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drake
May 11th, 2001, 10:19 PM
I have a fairly old aluminum tank that has been quite abused. It has been bounced around while going through the surf just a few too many times.... there is hardly any paint left on it at all. I would really like to refinish it so that it would look all pretty again :) Has anyone ever tried to repaint a scuba tank before? What kind of paint works well? Can it be done with normal spray paint or do I need an air compressor/paint gun? What is the best way to get the old paint off? Should I use some kind of chemical stripper or sand it off or what? Also if I strip off all the paint that means I strip off all of the inspection stickers also. Am I going to have a hard time getting it inspected again?

Thanks

Rick Murchison
May 11th, 2001, 10:28 PM
Most any aircraft grade aluminum cold stripper is ok for aluminum tanks, but you should query Luxfer (or whoever your tank manufacturer is) for the exact strippers they approve. Painting, on the other hand, is a different matter. Because paint can hide corrosion, it's generally advised that we users don't paint tanks at all - and many facilities won't fill repainted tanks for fear that a paint job has been "baked" on, a process which detempers the metal and makes the tank weak and a potential failure on fill. At the least, many facilities will require a post painting hydrostatic test of the tank before filling it.
You might want to just keep your beat-up paint job as a sign of your vast experience.
Rick

turnerjd
May 14th, 2001, 08:10 AM
IF you do really want to paint it, small cans of car type spray paint work very well.

An old club I was in had a problem with students leaving tanks allover the place (and then other people collecting 'unwanted' tanks). A few cans of purple and fluorescent yellow paint later no-one could miss our tanks, and remarcably few went missing after that!

IF you are going to paint it, use a thin coat, just enough to give it the colour, as rick sais, painting can often hide nastyness! (DON'T bake the paint on, and don't spend lots of time preparing the tank)

Jon T

devjr
May 20th, 2001, 07:06 PM
I visited a dive shop at a marina in Fort Lauderdale, sorry, don't remember which. For a nominal fee, they would have your old tank stripped to bare metal and clear coated. The redone tank on display looked silvery and brand new.

drake
May 20th, 2001, 11:48 PM
I guess for now I will just keep it like it is until I can find a place to do it professionally. Every time I look at it, it does remind me of the couple hundred happy hours spent bouncing around trying to get through the surf in Majuro. It's too bad my BC's didn't fare as well as my tank :) My next thread will have to be "anyone know of a good way to patch about 500 holes in a BC?" It's too bad I can't take the 3 BC's I have that all leak and make a franken-BC that doesn't leak :)

Rick Murchison
May 21st, 2001, 08:22 AM
HHHhhaarrr!
Franken BC indeed...
Send pictures!
Rick

TexasMike
November 2nd, 2001, 01:01 PM
I am now the proud owner of my first four AL80 tanks (used ones). And my vanity would benefit if I was able to repaint them.

A search of the board shows that we haven't discussed this yet. Any hints, tips, techniques, types of paints, etc., I should use to accomplish this?

Was kinda thinking of doing two of them with a really strange custom design (barber pole, woodlands camo, TSDT logo, etc)

herman
November 2nd, 2001, 06:20 PM
Mike,

You may not want to paint them. Some diveshops can get very picky if they see the tank has been repainted. Reason being that if the tanks were repainted and the paint baked on in an oven, there is the possibility that the temper of the AL has been compromised. I am sure you don't intend to bake them but the shop does not know that. Besides, old beat up tanks make you look like an old pro.....That reminds me, got to go beat up on my tanks some more.. By the way, how did the sub dive go, I have not heard..

Herman

Dee
November 2nd, 2001, 06:54 PM
Every nick and ding in that original paint job was hard earned by that tank! Wouldn't you love to hear the stories it could tell?

Personally, I like the looks of a galvanize or brushed alum. finish. It looks cleaner, you can readily see the condition of the tank and you don't have to keep repainting it to keep it looking good. Just write your name in paint pen, or magic marker around the top of the tank so you can spot it easily at the dive shop.

And all those cool stickers you like but are advised not to stick on your tank? Put them around your tank boot.

DoubleBubbles
November 2nd, 2001, 07:02 PM
I have seen these vinyl sleeves that cover your tank at some local dive shops. They come in a variety of colors, and may be the best route to go. I think they also have some designs available printed on them too.

joewr
November 2nd, 2001, 08:11 PM
something subdued and tasteful? For example, a frog wearing a dive mask and carrying a Texas State Flag? Maybe Artsprite (aka Patty the Swamp Master) can rustle something up for you? ("rustle up" is probably a poor choice of words in your part of the country...).

Or how about a Texas Longhorn wearing a dive mask? But, maybe the most appropriate would just be a Copenhagen decal...

Joewr...

DoubleBubbles
November 2nd, 2001, 11:01 PM
Now that has to be a sight; watching your dive buddy dip a little Copenhagen then spittin' underwater. I hope they swallow instead.

Bob3
November 3rd, 2001, 01:33 AM
First things first.
Only FINE CUT chewing tobaccos should be used while diving. Leaf types can plug the exhaust valve on your regulator, where fine cuts can be flushed through. :D

On to the paint.
Never heat an aluminum tank any warmer than your armpit.
#1 Remove old paint. Run to your local auto parts store & grab some aircraft stripper. It'll be safe to use on the aluminum. flush, wash and dry after stripping, and hit with a scuff pad. You may just want to leave the tank with that finish, or haul in to someplace for glass bead blasting for a fine bare satin finish.
If ya HAVE to paint it, immediately after scuffing apply a light coat of zinc chromate primer. Apply a second light coat. It's MUCH better to use multiple coats than to get goobers & runs hanging & have to sand 'em down. (goes for the paint, too).
For paint, I suggest a plain old high gloss Rustoleum Appliance White; fairly tough but easy to retouch or strip again. Both the primer & paint are available in spray cans.
If you know how to run a Binks #7, drop me an e-mail for other paint options.

I'd still go with the bare aluminum like Dee says.

TexasMike
November 3rd, 2001, 11:30 AM
B^cubed:

Thanks for the info, that is what I was looking for. And I agree with the basic plain satin finish. If I ever purchase new tanks, this is what I planned on getting anyway.

Joe: No longhorns on my tanks fer me, buster. Remember, I are an Fightin' Texas Aggie and proud of it! I can even count to twenty if I take my dive booties off!

The reason for the oddball designs is so that I can pick them out of the crowd of tanks and people can pick me out of the crowd of divers underwater.

joewr
November 3rd, 2001, 01:29 PM
Geez, Mike,

You reminded me of the time that I visited my son at Marine OTS in Quantico and I asked on of his roomies about the Longhorns...guess who else was an Aggie?

So what about a BIG AM (I cannot seem to make the A lie over the M here...gotta talk to LD...) with a dive mask hangin' on the A?

Joerw...wondering if Mike knows the one about the 6th generation Aggie and the family beer mug...

TexasMike
November 3rd, 2001, 03:32 PM
No (but want to hear it)

I do have an Aggie Coffee mug (the one with the handle inside of the mug)

Also, did you hear on the news about the Aggie who was hospitalized after failing to join Osam bin-Laden's terrorist organization? He suffered third degree burns around his mouth and lips when he tried to use the tail pipe to blow up a bus.

joewr
November 3rd, 2001, 04:21 PM
TejasMiguelito,

The joke I am thinking of was taught to me by the shavetail Marine Lt. whom I "insulted" by asking about the Longhorns...it requires use of the hands...thus, we will have to wait until Barbara and I go on a swamp dive with your gang. Barbara will probably, though, only be a very interested spectator. She thinks 60 ft is poor vis!

Joewr...wondering why Dee wears those rose-colored lenses...is rose-colored mud prettier...

Dee
November 3rd, 2001, 05:50 PM
Originally posted by joewr
TejasMiguelito,

Joewr...wondering why Dee wears those rose-colored lenses...is rose-colored mud prettier...

'Cause when I started diving and needed RX lenses in my mask, I trusted the dive shop who told me that's what I needed! Now I'm used to them and can't tell the difference. Besides, it DOES provide another color other than green ;)

joewr
November 3rd, 2001, 11:20 PM
Originally posted by Dee


'Cause when I started diving and needed RX lenses in my mask, I trusted the dive shop who told me that's what I needed! Now I'm used to them and can't tell the difference. Besides, it DOES provide another color other than green ;)

I like my explanation better!

Joewr...ah, the romance of rose-colored mud...my old san anton rose colored mud...

blacknet
November 4th, 2001, 12:29 AM
Hello,

The *ONLY* way I would paint any scuba tank is for decoration purpose only. It's expensive to do it correctly, it's time consuming, some shops will get all anal and drill you 20 billion questions and then end up hating you when you slam the manufactures manual on the tank onto the counter and tell them you followed every guideline/rule/regulation.

Personaly, if any shop gives me grief about filling my tanks then that's not a shop i'll revisit.

custom painted tanks will take damage from various areas and it's impossible for you to prevent it (unless it's for decor) and they always wind up looking like trash.

Ed

Divemstr13
November 7th, 2001, 09:08 AM
Any shop that sell's Luxfer tanks cans order you custom printed tanks fron their distributor ScubaLux , in a bunch of different colors. They use some system that makes the graphics bond to the tanks coating, real strong stuff. Nothing like stickers or stencils that are always peeling. Love my Nitrox tank graphic. You can even get a custom design or logo done relativly cheap.

TexasMike
November 7th, 2001, 10:36 AM
DM--

Thanks for the tip on new ones, but I've already picked up four used ones still on their original hydro (9/98) for a very sweet deal. And I'd like to paint them so that they can be somewhat "original" and will stand out of the crowd.

Norm
January 13th, 2002, 01:53 PM
I've always just used sandpaper and hand-roughed any exisiting finish. I then apply multiple coats of the cheapest stuff Walmart has - usually around .99 cents a can. Heck, my tanks live hard and they'll get scratched up and chipped soon enough. Just hit them with another shot of the cheap stuff and they look new again! :jester:
Norm
Tip: On new steel tanks apply a coat of clear laquer. This keeps them looking new for years! If they are of an oddball pressure, (like the old 95's that had plus/+ or a HP steel with 3500 psi on them), just take a laundry pencil and fill in the depression where the numbers are before spraying. This makes the stenciling really stand out and (semi) permanent.:doctor:

roakey
January 13th, 2002, 02:58 PM
Step 1: Remove boot
Step 2: Mask off valve
Step 3: Strip using zip-strip and a scotch-brite pad by 3M
Step 4: Unmask valve

That's it. Note the boot didn't get replaced. Any kind of boot, netting or covering will trap water and can lead to corrosion. The exterior of my AL80s look like, er, processed food and I'm kinda proud of 'em. :)

Roak

blacknet
January 13th, 2002, 03:03 PM
Hello,

NAA to much work. Even easier plan is

Step #1 call vendor
Step #2 order new tank in desired size and color with desired valve/boot
Step #3 pay for the equipment and enjoy

Ed

WreckWriter
May 2nd, 2002, 10:49 AM
Originally posted by roakey
Step 1: Remove boot
Step 2: Mask off valve
Step 3: Strip using zip-strip and a scotch-brite pad by 3M
Step 4: Unmask valve

That's it. Note the boot didn't get replaced. Any kind of boot, netting or covering will trap water and can lead to corrosion. The exterior of my AL80s look like, er, processed food and I'm kinda proud of 'em. :)

Roak

Hi Roak,

Zip-Strip is also Luxfer's recommended product but which type of Zip-Strip works best? I found their website and they make several versions. I have a set of Luxfer 80s that need to become bare aluminum and I would like to do it with as little wailing and gnashing of teeth as is possible.

Thanks for your time.

Tom

WreckWriter
May 2nd, 2002, 10:52 AM
Originally posted by devjr
I visited a dive shop at a marina in Fort Lauderdale, sorry, don't remember which. For a nominal fee, they would have your old tank stripped to bare metal and clear coated. The redone tank on display looked silvery and brand new.

Still no idea which one? General location (within Ft. L of course)?

Tom

Bob3
May 2nd, 2002, 10:55 AM
Look for a stripper that's approved for aircraft use. (hit the auto parts store)
If it doesn't eat something THAT thin, it'll be fine on a scuba tank.;)

WreckWriter
May 2nd, 2002, 11:00 AM
Found a place nearby that will do them for me at about $25. http://www.hydrostat.com/hydrostat.htm

May just do that to save the effort!

Tom

Swamp Rat
May 2nd, 2002, 04:26 PM
Mike isnt Deerfield beach right where we will be for Weckmania? If so I would get them to strip them. Then find a Graphic place and have them Photo engrave them. It does not harm the tanks and you can get any kind of design you want on them. Your pretty limited as far as colors go black, natural, gold, red, and shades of such. But the design can be as complicated as you want.

WreckWriter
May 2nd, 2002, 04:35 PM
I called them. They offer 2 finishes, just plain stripped "brushed" look, and the glossy look seen on their site. Turn-around time is 3-5 days. Cost is about $23 for the plain, about $29 for the glossy.

Tom

wannabe
May 2nd, 2002, 10:24 PM
Most painting (autobody) ovens don't get much above 140F because of concerns with CNG vehicles, fuel tank venting, and wrecking other stuff in the car that may not be high temperture friendly.

To start working with the temper of Al you will need to get to 300F+

With that said I would wait till a hydro was needed so if there was an issue from your dive shop about filling the tank the concerns would be squelched at that point.

BlkPnthr
October 7th, 2002, 04:04 PM
I'm looking for links to sites that will provide information or information from members on in-expensive ways yet, effective ways to strip paint, prime and re-paint scuba tanks. The club I belong to is looking to "refresh" our rental tanks as the paint is peeling, have a few different colours and we'd like to standardize the colour. Anyone with information that they think could benifit us, we'd certainly appreciate it. We're dealing with both steel and Aluminum tanks.

Thank You

Genesis
October 7th, 2002, 04:12 PM
is that both heat and mechanical removal (e.g. sandblasting) are prohibited.

This leaves chemical strippers.

As for repainting, aluminum is no fun. The trick is all in the primer, and good aluminum primers are VERY toxic. Be extremely careful not to get any INSIDE the tank!

I'd be looking at a two-part catalyzed topcoat paint if I was doing this. That stuff is not cheap, but its tough as nails. It also needs to be sprayed for good results, and most of these two-part paints contain isocyanates (BIGTIME toxic hazard - as in wear a pressure-fed moonsuit!) No single-part paint is going to hold up as well.

You might want to talk to someone who paints aluminum and steel boats (not bottom paint - topsides refinishing) - you might even be able to get them to spray your tanks with the "leftovers" from a boat job at a MAJOR cost savings.

Dee
October 7th, 2002, 04:29 PM
They won't be pretty very long. Chemically strip the old paint off and to customize them, put a nice club sticker on them.


You won't be looking at chipped paint again in a few months.
With no paint, you can always tell the condition of your tank.
The most you'll have to do to keep them looking nice is replace the club stickers.
It's lots cheaper and less work!

FredT
October 7th, 2002, 04:50 PM
"Bead blast" aluminum tanks with walnut shell media or ground corn cob. This will remove the paint, polish the exterior of the tank, and take little effort. If all else fails use a timed aircraft paint stripper, but this is expensive if doing a bunch of them. Walnut shell in a media recycling bead blasting booth is about the best bet $ and time wise. If using regular abrasive use a glass or silica free "slag" media of about 160 grit, and move fast. Black Beauty is a good media for blasting aluminum, but it cuts fairly fast if you dwell on a single spot AT ALL! 160 grit at about 90psi nozzle pressure and 8" nozzle separation will turn the surface to a nice satin finish fairly quickly. Blasting on a tumbler eliminates handling time and speeds up the process considerably. As Dee said, aluminums are best left bare and unbooted. When blasting use an OLD valve to protect the seal areas. It won't survive the process in useable condition.

For steel tanks the same methods will work, but finish topcoat with ZRC where ever the galvanizing is missing or damaged. I would avoid the Black Beauty and/or power brushing any tank that may have an intact galvanizing coating under the finish.


Dee is right with sticker idea. For semi-permanent ownership marking on either type use a laquer based coating and stencil. Permanent markings are best applied to the VALVE with metal stamps. (Misc stamps into the tank can annoy DOT/TC unless done in specific places and limited stamp depth.)

FT

Genesis
October 7th, 2002, 07:08 PM
is it kosher to use a physical removal technique (e.g. sandblasting) on tanks? I know that heat is absolutely verboten, but I had heard that sandblasting was a "no go" as well as it would void the existing hydro (and require a retest after being complete.)

FredT
October 7th, 2002, 07:59 PM
Genesis once bubbled...
is it kosher to use a physical removal technique (e.g. sandblasting) on tanks? I know that heat is absolutely verboten, but I had heard that sandblasting was a "no go" as well as it would void the existing hydro (and require a retest after being complete.)

Correct. Agressive sand blasting can erode material to a thickness less than minimum wall very quickly in a manner that can't be picked up on a visual. The media I suggested however are either softer than the metals being blasted, so they VERY non-agressive to the pressure vessel wall, or are so fine the cut rate is negligable. All will carry enough energy to remove paint, especially paint that is already experiencing adhesion failures. I've used the fine Black Beauty on VERY thin wall aluminum buoy hulls to prep the surface for re-application of a Mare Island Epoxy paint system. The trick there is to have a very fine abrasive particle and medium to low air pressure. 160 mesh will have a particle size smaller than .006" with most of it below 0.003". It looks like dust, and can clog a baghouse filter in a hurry. Media this size is effectively not reuseable, and it takes a lot to do a tank. Walnut shell will have a particle size about .06 to .1", with ground corn cob about twice that. Since both walnut and corn cob are re-useable the net abrasive material cost for doing a batch of tanks starts to get reasonable if doing more than about 6 tanks. The "polished" look either walnut or cob will give to the tank is a plus if doing the refinish for cosmetic reasons. Dry ice is another good paint removal blast medium that won't damage the base metal, but the investment necessary to do that one is $ignificant. Fine particle size Calcium Carbonate (limestone) media is also a realistic option.

My personal opinion is that the time to do tank exterior cleaning is when the bottle is due for hydro and a complete valve overhaul. It should also be done before the hydro. This allows for a good pre-hydro visual to be completed. That way you can cull a bad tank from the lot ealrly in the process. If there is external corrosion on a tank bad enough that it requires an immediate refinish an "extra" hydro may be a good idea anyway. If the tanks are just "ratty looking" on the outside with no visible exterior corrosion I'd probably let them ride to the next rebuild date.

FT

Genesis
October 7th, 2002, 08:18 PM
for the clarification - that's what I thought...

GP
October 8th, 2002, 08:33 AM
Fred, I have an OMS/Faber steel tank that has corrosion on the boot area of the tank. What's the best method to remove the corrosion? Should I hand sand it down and coat with ZRC and repaint? The tank is due for a vis and hydro next April. Just wondering if I can save this tank or not at this point.

FredT
October 8th, 2002, 09:23 AM
If any is involved it's way thin and not very effective.

If hand sanding follow up with a phosphoric acid rinse. Kano Labs Exrust is a good pretreatment product. This will remove all poorly adhering zinc and any residual rust.

After a thorough inspection for pits the tank can be recoated with ZRC. Do clean and refinish the entire tank exterior. The OMS Imron doesn't seem to be holding up well.

Rework cost if you DIY should be about $60 for the first tank, less for later tanks as the materials can mostly be reused. It's still cheaper than going for new bottles.

FT

GP
October 8th, 2002, 12:43 PM
Thanks for the info Fred. Where can I obtain the products you speak of? Also, if I remove all of the rust and repaint the whole tank, is it necessary for me to strip the "entire" tank even in the areas that show no signs of corrosion or is just repainting sufficient enough?

JDostal
October 8th, 2002, 05:19 PM
Yeah...I'd have to say go this route. I know you said you were looking to *cheaply* paint tanks...but it's not going to be very cheap no matter how you do it.

My diving friends were telling me the story of this idjit that spent a LOT of money to paint his tanks the color of his truck...and then screamed and yelled every time they were moved because he didn't want them to get scratched!!!

Tanks will get beat up...straight aluminum w/ a sticker will last much longer....and be dirt cheap.


Dee once bubbled...
They won't be pretty very long. Chemically strip the old paint off and to customize them, put a nice club sticker on them.


You won't be looking at chipped paint again in a few months.
With no paint, you can always tell the condition of your tank.
The most you'll have to do to keep them looking nice is replace the club stickers.
It's lots cheaper and less work!

FredT
October 8th, 2002, 06:59 PM
GP once bubbled...
Thanks for the info Fred. Where can I obtain the products you speak of? Also, if I remove all of the rust and repaint the whole tank, is it necessary for me to strip the "entire" tank even in the areas that show no signs of corrosion or is just repainting sufficient enough?

As far as doing the entire tank, I would. Then again I have been accused of being real anal about some things. If the "factory" finish fails in one place, what will prevent it failing in another area. If the process has failed, fix the process, don't patch it and have to do it over again later. A double coat of ZRC is the next best thing to hot dip, and it won't void the DOT/TC roll mark.

For ZRC check the website for a dealer near you. It ain't cheap, but it's worth it.

http://www.zrcworldwide.com/

For Exrust contact Kano Labs at: http://www.kanolabs.com/ or 800-311-3374

Check the industrial supply houses in your area for bagged abrasive media and shell media. Ground corn cob can be had at most feed stores as animal bedding. It takes a bunch of cob unless you have a recirculating blast cabinet and you can upsize the suction tube. Walnut, almond, peach pits, or pecan shells would be a better bet if you are reusing media. What type shell material you can find locally will vary by region. All shell media of similar size will work about the same provided particle size is similar.

BTW Caustic strippers CAN be used on a steel tank. Don't get them near an Aluminum tank though. The reaction of aluminum with a caustic stripper is quite impressive.

FT

GP
October 9th, 2002, 11:02 AM
Thanks again Fred. I ordered some Exrust today and I plan to get some ZRC as well. Since I live in an apartment and don't have access to a nice workshop with an air compressor for blasting and what not I'll have to use stripper to get the paint off the tank. After reading some past posts it sounds like it's going to be a crappy job but in the end it should be worth it. Now with the ZRC would it be ok to apply the two coats with a brush or mini roller or should it only be sprayed on? Again, I don't have an air compressor and spraying equipment so I pretty much need to do the brushing method but I'm wondering if that is an adequate way to apply the ZRC to a "tank" before I go ahead with this project.

FredT
October 9th, 2002, 12:25 PM
ZRC is good for brush on, but reportedly it does come in an aerosol now for field touch-up. I haven't used the aerosol yet. If brushing you may want to do several thin coats instead of two thick ones to ensure you don't have any holidays in the coating.

Be sure to mix the stuff thoroughly and often whichever method you use. The zinc powder it contains wants to drop out of suspension pretty quickly.

FT

Bob3
October 9th, 2002, 12:42 PM
Can't recall the name, but we used some aerosol "cold galvanizing" spray back when I used to be a pipefitter.
Maybe if I think for a while... [darn CRS]

Paint stripper suitable for aircraft use [safe for aluminum] is available from the average auto parts store, after that a satin finish can be applied to Al tanks by hand with a Scotch scuff pad.

If you just HAVE to paint the sucker, an immediate application of zinc chromate primer is in order.
RustOleum makes a nice high gloss "appliance white" that we used to use on rockets. Sticks tight & EZ to touch up.
:mean:

thethumper
October 9th, 2002, 01:43 PM
FredT once bubbled...

BTW Caustic strippers CAN be used on a steel tank. Don't get them near an Aluminum tank though. The reaction of aluminum with a caustic stripper is quite impressive.

FT

Hey Fred,

Does this include Naval Jelly?

FredT
October 9th, 2002, 02:00 PM
thethumper once bubbled...


Hey Fred,

Does this include Naval Jelly?

Naval jelly is a jel form of phosphoric acid. Acid eats aluminum, but nowhere near as fast as a caustic like lye.

Acid = high in H+ ions
Caustic = high in HO- ions

Both are bad for light metals, but caustic is orders of magitudes worse. If you remember dry Drano drain cleaner the active ingredients were dry lye and aluminum chips. Just add water and stand back.

FT

Bob3
October 9th, 2002, 02:30 PM
Phosphoric acid, ain't that the stuff in Coca Cola?
Coke makes a good "liquid wrench" alternative for rusty bolts.
Meat tenderizer, too.
;)

thethumper
October 9th, 2002, 04:08 PM
FredT once bubbled...


Naval jelly is a jel form of phosphoric acid. Acid eats aluminum, but nowhere near as fast as a caustic like lye.

Acid = high in H+ ions
Caustic = high in HO- ions

Both are bad for light metals, but caustic is orders of magitudes worse. If you remember dry Drano drain cleaner the active ingredients were dry lye and aluminum chips. Just add water and stand back.

FT

Does that mean I can or can't use Naval Jelly on Al tanks, or no?
:confused:

FredT
October 9th, 2002, 04:57 PM
thethumper once bubbled...


Does that mean I can or can't use Naval Jelly on Al tanks, or no?
:confused:

:banging: Naval jelly is designed to be used to remove rust, NOT paint!

I have never seen a case where it would be needed on AL!


That said, I'd avoid it if possible. There is a product called "Aluminum Jelly" used to brighten structural & architectual aluminum railings if heavily discolored, but the discoloration is caused by a tightly adhering passive corrosion film that actually helps prevent seawater corrosion. Leave it be unless you have other overriding considerations.

FT

thethumper
October 9th, 2002, 08:27 PM
That would be a no. That's sufficient. I used to use Naval jelly to strip blocks & heads of paint, that's why I asked. The adhesive on the paint on these 2 Al80's is shot. I peeled the VIP & Mnfgr stickers off & the paint came w/it. I was able to flake it off w/my nail. So it's back to bare Al & Scotch Brite.

Thanks!

FredT
October 9th, 2002, 09:07 PM
Just take it to a coin operated car wash and hit it with the wand at maximum force. Should be done in a few minutes for less than $3


FT

thethumper
October 10th, 2002, 08:41 AM
FredT once bubbled...
Just take it to a coin operated car wash and hit it with the wand at maximum force. Should be done in a few minutes for less than $3


FT

Thanks Fred. I don't have a pressure washer, but though about it, but hadn't considered the self car wash. Good idea. Thank You.

David

joel_pratt
October 14th, 2002, 01:04 PM
I have used black beauty to blast all of my aluminum 80's. I leave it sans paint and they have so far lasted 2 years with no problems. Both have been through Hydro and multiple vis+ inspections as well as being thrown around. Marking is not as noticable and no paint to peel. Our local lds only rents aluminum tanks that came with a blasted, raw finish...they always look new!

Helius
January 12th, 2003, 02:26 PM
Hi ppl,

Anyone ever tried to paint over his tank? I want to draw a pic. or something like that?
has anyone tried that before?
which kind of paint? how to make sure it will last?

If not, what do you think about a sticker?

C_C
January 12th, 2003, 02:56 PM
Do not apply direct heat to your cylinders...

350 degrees F is enough to condemn an aluminum cylinder!

Also, stickers that MAY obscure corrosion/cuts/dings/gouges SHOULD be removed during the Visual Cylinder Inspection done by a PSI Certified inspector.

What image did you have in mind?

C_C

Helius
January 13th, 2003, 06:25 AM
I'm cgecking before trying anything that might cause any damage. :)

BTW: I have a steel tank, if that mattrs.

SDAnderson
January 13th, 2003, 08:22 AM
Repainting your tank may cause you problems at your next visual inspection - this is one of the indicators that a tank may need to be referred for hydro. The inspector can't see what you hid under the paint job and will also be concerned about that you might have baked the finish and destroyed the tank.

Additionally, getting paint to adhere to the surface of many tanks is very difficult. Galvanized finishes and other surfaces aren't designed to take paint well and you should never thermal cure a scuba tank - even empty of air.

If you want to paint your tanks, start with the manufacturer. They usually can provide the best information and instructions on how to proceed.

Likewise, stickers must be removed prior to inspection so that the surface of the tank can be seen. Little stickers sometimes come off without being destroyed, big ones never do. Stickers also tend to trap water against the tank, magnifying the corrosion problem enormously.

Then again, you could view those dings and scrapes as memories and well-earned scars and leave the surface alone. Your tanks will probably last longer if you leave well enough alone. There are stickers and nylon mesh (available on eBay and many dive shops) but remember that, come inspection time, if they don't come off easily they will need to come off hard.

Steven

Rick Murchison
January 13th, 2003, 08:44 AM
I generally don't recommend paint - other than some sort of clearcoat (I personally use epoxy) on a steel tank as paint can hide rust. But if you must paint, epoxy (the real stuff you mix just before painting) will stick to most surfaces pretty well at room temperature - and room temperature is what you want.
Rick

Helius
January 14th, 2003, 04:19 PM
I thought to make it look better.

Check these url's plz ...
http://www.island-scuba.com/Merchant2/merchant.mv?Screen=CTGY&Store_Code=001&Category_Code=gallery

http://www.island-scuba.com/Merchant2/merchant.mv?Screen=CTGY&Store_Code=001&Category_Code=cygraphics

AzAtty
January 15th, 2003, 10:42 AM
...that these guys only offer the custom paint job with the purchase of a new tank. That would address the issue of rust and damage cited above. They don't say enough about the paint they use or the drying procedure, although I get the distinct impression that they air dry the tank.

Whether you want to spend money on the custom paint job is, of course, your decision. In my experience, tanks tend to accumulate some scratches and minor dings that will mess up the custom job, so the nice graphic you see on the first day will probably look like it has a bad case of leprosy within a short period of time. That will be compounded by the likelihood that the graphic paint probably won't adhere as well as the manufacturer's paint.

don harris
January 18th, 2003, 09:54 AM
I had a tank painted in fall and I really never mean to bang things around but 26 dives later the tank looks worse then it did when it was original (aluminum 80) there was a clear coat put on But it still chips off So :) just my opinion :)original is meant to stay original ,but I have seen guys with custom painted decals and they have kept them nice for a long time ,no chips, no scratches this could never be acomplished by me ;-0

Hallmac
January 18th, 2003, 11:41 AM
I paint tanks all the time! Here's what I do.

I glass bead blast all the old paint off (if you dont have glass beads use the finest sand you can find. You dont want to remove metal) and prime the tank with a rust preventing primer. When completely dry I use spray epoxy and allow to dry for 72 hours. Paint on your design and clear coat. Allow to air dry on all stages.

The reason I blast all tanks is to remove excess paint levels that hide the DOT stampings and the Hydro dates. Painting this way all markings are very visible.

I usually get about 100 dives before they start looking poor and need a new paint job. Hopes that helps.

PS. I Hydro tanks everyday and this will not harm or prevent them from being tested.

Hallmac

Rush
January 18th, 2003, 11:56 AM
Hallmac,

What paints and what clear coat do you use ? As an airbrush hobbyist and avid scuba diver, I have always wanted to combine the two and paint one of my tanks, and would like some advice from someone who has experience in this.

Hallmac
January 18th, 2003, 10:25 PM
Well I used to use paint from Dupont that I got from N.A.P.A. Auto Parts that was designed for marine use. However I currently use this combo.

Epoxy Spray Paint from Kryon ( weird I know ) but it is a very hard chemical resistant fast primary color. After 72 hours it becomes stable enough to top off with enamel designs without chemical orange peal. I top coat my designs while wet with an enamel clear coat.

2 coats of primer
2 coats of epoxy
1 coat of design
3 coats of clear

has worked very well for me

Hallmac

Rush
January 18th, 2003, 10:36 PM
That is just what I wanted to know. Now, one of these days I'm gonna have to be brave enough to attempt painting one of my tanks !

Butch103
January 19th, 2003, 01:49 PM
I was going to have my steel tank's vis done and then clean the tank, (stickers and residue paint)...thn have my LDS reapply the sticker and then just tremclad it........Oh wellll.......................( It was going to be a glitzy gold)

Hallmac
January 19th, 2003, 03:48 PM
Do you normally use lacquer, enamel, or polymers in your air brush?

Hallmac

scubaspider
July 14th, 2003, 07:11 PM
Does ne one know which method is best to paint a tank and would it harm the tank?? I was considering powder painting my tank which involves baking the tank in an industral type oven designed for such. Of course I wouldnt do this w/ the valve in place but would the tank be ok if exposed to a high amount of heat for a couple of hours???



:spider:

ScubaPete
July 14th, 2003, 07:52 PM
You could always try to rattle can it.:bonk:

If it doesn't stay on long you could change you tanks "style" for cheap:flusher:

blacknet
July 14th, 2003, 08:05 PM
Hello,

Let me stress this.

NEVER BAKE A TANK!

Let me repeat that

NEVER, EVER, BAKE A TANK!

High temps will destroy the tank and cause it to explode by weakening of the material. There should be a label on your tank detailing specific instructions for heat damages among other things.

If you are wanting to paint a tank then consider some epoxy type paint that does not use heat. There are plenty out there. Also look at airbrushing and some clear epoxy coating for protection.

Ed

chsmoke3
July 14th, 2003, 08:20 PM
Bad idea if you are thinking about doing this to an aluminum tank!!! Luxfer says that any of their tanks must be condemned if they ever reach a temperature of 350 degrees F. Are you planning on powder coating steel or aluminum tanks? I am no metallurgist, but baking aluminum would be a bad idea. I'm guessing that it would anneal the metal making it soft. As far as steel goes, I don't know for sure, but probably the same case. Anyone else have a method?

pasley
July 14th, 2003, 08:36 PM
One of the reasons cited for tanks failing and exploding is a change in the comosition of the AL alloy caused by the heat generated by overfilling the tank.

This of course is a lot less than you are planning to do. Baking the tank can potentially change the charateristics of the alloy the tank is made of with potentially deadly results.

http://www.scubabomb.freeservers.com/

has a nice article on a guy who was injured getting ready to fill an in VIS (2 months before) and in hydro tank that exploded to do failure of the alloy.

NO EXPERT, but that is my $0.02 worth.

Gilligan
July 14th, 2003, 08:43 PM
Don't even think about heating up an aluminum scuba tank. There is a photo on this site that will give you some idea of the damage an exploding aluminum scuba cylinder can do:
http://www.scubabomb.freeservers.com/Scubadag.htm

Rooster1
July 14th, 2003, 09:29 PM
Does anyone know how hot a down draft paint booth gets when you bake the paint?? I am certain it is not 350 degrees which is the annealing temperature on an aluminum alloy scuba tank. There has been many tanks painted in down draft booths and then baked. I have been in these booths and can tell you from experience that the inside of your car and especially your trunk in the summer months when you are hauling your gear or leave one tank in the trunk while you do your first dive is just as hot or hotter then the heat that I have been in when in a paint booth.

DA Aquamaster
July 14th, 2003, 09:34 PM
Powder coating may be an option on steel tanks, but you'll need to see how compatible it is with a galvanized finish. If you have a galvanized steel tank, just leave it that way - much less work in the end as the galvanized finish is much more durable. Getting paint to stick to a galvanized scuba tank is a problem even with a primer made for galvanized metal, but under no circumstances do you want to remove the galvanized finish. The average tank takes a lot more abuse than the average car and the paint tends to chip.

With an aluminum tank (as pointed out above) you are limited in the amount of temperature that can be used to cure a two part or epoxy paint. This can make the finish less durable than desired.

Also you need to be aware that a lot of dive shops (the smart ones) will require a new hydro on a newly painted aluminum tank before they will fill it. There have been cases of tanks being baked in the painting process and there have also been cases of tanks being repainted after being in a fire. So new paint can make a dive shop nervous and you may want to wait to paint the tank until it's due for a hydro anyway.

blacknet
July 14th, 2003, 09:35 PM
Rooster1 once bubbled...
Does anyone know how hot a down draft paint booth gets when you bake the paint?? I am certain it is not 350 degrees which is the annealing temperature on an aluminum alloy scuba tank. There has been many tanks painted in down draft booths and then baked. I have been in these booths and can tell you from experience that the inside of your car and especially your trunk in the summer months when you are hauling your gear or leave one tank in the trunk while you do your first dive is just as hot or hotter then the heat that I have been in when in a paint booth.

Hello,

Getting a fill, throwing the tank into your trunk then driving to a dive site can be enough temp to condem your tank(s), easily.

Ed

Rooster1
July 14th, 2003, 09:57 PM
blacknet once bubbled...


Hello,

Getting a fill, throwing the tank into your trunk then driving to a dive site can be enough temp to condem your tank(s), easily.

Ed

do you know if this has ever happened? The reason I ask is because I have picked up some very hot tanks from vehicles and from a fresh air fill. In fact I remember last year on a couple of occasions picking up a couple of my tanks that were just filled at the lds and I was amazed at how hot they were, how ever if the heat you are talking about from the tanks in the trunk while getting to a dive site, if they as you are saying can be easily condemned then wouldn't almost ALL scuba tanks get condemned as almost ALL of them will reach hot temperatures in trunks and during fast "HOT FILLS"??

Genesis
July 14th, 2003, 10:21 PM
First, the critical temperature for AL tanks is ~350F. That's HOT. Way beyond what you can reach in a car on a hot summer day.

But, heat-curing paint is a big no-no. I wouldn't bother repainting anyway; it'll just get banged up again.

Boogie711
July 14th, 2003, 11:07 PM
With respect, are you going to tell me that getting a fill, tossing the tanks in my trunk and heading to a dive site would be enough to condemn my tank?

That's what it looks like:

Getting a fill, throwing the tank into your trunk then driving to a dive site can be enough temp to condem your tank(s), easily.

Come on!

Condemnation point for Aluminum tanks is 350 F. 350!!!

Water boils at 212 degrees. There is NO WAY a fill and a hot trunk ride even approaches 350. Stick them in a hot, black trunk at high noon in Arizona, straight off the compressor, and you're not hitting anywhere CLOSE to 350.

I'd be REALLY interested to see your source on a statement like that. Sheesh.

scubaspider
July 15th, 2003, 12:37 AM
DA Aqua,


This would be a steel tank that I would be painting. As far as the finish on it or the condition of the tank, I have no clue. This tank is coming from my father's friend who is getting out of diving cuz of his time constrants. This was an idea to make a tank look something other than the regulator single colors and put some designs on these things making them more interesting than just a tank. I was going to try and make a web design for a spider....go figure. Another brainstorm idea was to paint the tank like a shark and place a fin on the tank, but then i'm playing w/ buoancy and glues and stuff so, that wouldnt be good, but it would look cool underwater!!!


thanks,

~spider

Boogie711
July 15th, 2003, 08:05 AM
Like they all say - it's going to get all scratched up anyway. At least if it's SUPPOSED to look scratched up, it will be cool. A nice design all scratched up will look like crap.

And you don't want to put a shark fin on. A) it will screw up bouyancy/trim, B) it will make it a royal pain to thread through a cam band, and C) it will look REALLY bad when it gets scratched/dinged/squished/mangled, etc.

Just run with what you got. If it's all scratched up, as long as it's not an issue with rust or corrosion, consider it 'well loved.' :)

ReefGuy
July 15th, 2003, 08:50 AM
I saw a website offering shrink wrap tank skins. They have different designs, and when you put them on, you heat them with a blow-dryer, until the plastic shrinks. It's then semi-permanent, but can be cut off with a knife (apparently, you just score and peel).

Is this a bad idea?

roakey
July 15th, 2003, 08:54 AM
ReefGuy once bubbled...
I saw a website offering shrink wrap tank skins. They have different designs, and when you put them on, you heat them with a blow-dryer, until the plastic shrinks. It's then semi-permanent, but can be cut off with a knife (apparently, you just score and peel).

Is this a bad idea?
Anything that traps water (especially salt water) against metal is a bad idea. That's why even tank boots are a bad idea.

Roak

Ps. I just combined the dozen or so tank painting notes into just two notes, painting AL tanks and painting steel tanks. Now it's two-stop shopping for all cylinder painting needs. You may want to go back and reread this note from the beginning to get all the information available.

DawgPaddle
January 7th, 2004, 02:28 PM
Hello All -

Just curious, is painting (art) on aluminum 80's a problem? Is is not recommended or legal (anything like that). I ask because my wife is an artist and I have some ideas that I'd like her to paint on the tanks but wanted to find out more specifics on it.

Type of Paint
Advice
No-No's
Safety Factors

My apologies if this topic has already come up. If so, please point me in the right direction.

Thanks,

DawgPaddle

cyklon_300
January 7th, 2004, 02:50 PM
is a waste of effort IMO...if you dive much at all, it'll just get scratched and look ratty.

If you must paint, do NOT heat-cure (bake) the cylinder...

roturner
January 7th, 2004, 03:02 PM
Hello All -

Just curious, is painting (art) on aluminum 80's a problem? Is is not recommended or legal (anything like that). I ask because my wife is an artist and I have some ideas that I'd like her to paint on the tanks but wanted to find out more specifics on it.

Type of Paint
Advice
No-No's
Safety Factors

My apologies if this topic has already come up. If so, please point me in the right direction.

Thanks,

DawgPaddle

painting is ok. heating is not. If you heat your tank to cure or to remove old paint then you may (probably will) destroy the metal and it could (probably will) blow up when you fill it.

Some people report that rust paints like what you would use on a car work well. Also, if you were to put a coat of clear lacquer (no heat cure types) on over the paint then it will scratch proof it a bit.

Have fun.

R..

IndigoBlue
January 7th, 2004, 03:10 PM
Eventually I will paint all of my tanks black. I just have not gotten around to it yet. They are ordinary metallic silver now, a boring color.

Some divers have really wild, mod paint jobs, like flames or mermaids etc. It looks truly beautiful, like an underwater Altimira.

You should use enamel paint. You are not permitted to bake the paint job. It must air dry.

You cannot obscure the serial number or hydro date either, or the other DOT info like working psi, composition code, etc. I would give the whole tank one thin base coat, then mask the I/D info so that subsequent layering does not obscure it.

Take off all stickers first, then after painting, have the tank(s) vis-ed (and O2 cleaned if needed).

Make sure your paint job matches your exposure suit. You don't want to clash colours!

IndigoBlue
January 7th, 2004, 03:15 PM
is a waste of effort IMO...if you dive much at all, it'll just get scratched and look ratty.

If you must paint, do NOT heat-cure (bake) the cylinder...

When it then gets all scratched and ratty looking, then it looks really cool, like you have actually been somewhere!

cyklon_300
January 7th, 2004, 04:31 PM
When it then gets all scratched and ratty looking, then it looks really cool, like you have actually been somewhere!

I don't like murals, bumper stickers, mesh wraps, anodizing, paint or anything else on my cylinders...the VIP and O2 clean stickers are enough adornments. The boring galvanized or unpainted aluminum is fine with me.

DawgPaddle
January 7th, 2004, 04:50 PM
I'm not meaning the whole tank as a scene or something, I could bo buy a cover for that, just perhaps a logo or something like that. Our kids (at home) are Bulldogs, and I was thinking of a Bulldog diver or something.

No Heating For Sure

CBulla
January 7th, 2004, 05:12 PM
Have fun and paint it! The scraching and smearing shows your active! :D

Druid
January 8th, 2004, 07:35 PM
is a waste of effort IMO...if you dive much at all, it'll just get scratched and look ratty.


That doesn't happen to all the painted steel cylinders that are commonly used in the UK

Maya
January 8th, 2004, 07:42 PM
NO HEATING! I still have nightmares from the AL 80 tank that exploded at around 1500 psi in our dive shop while it was being filled..due to baked on paint job..

GotAir
January 10th, 2004, 06:17 PM
But my question is ? are some colors taboo to use. I thought of painting my tanks fire engine red, but i thought I might be mistakin for a secue diver or something. is there any color code on tanks that indentifies the divers skills.

Mike

roakey
January 11th, 2004, 01:19 AM
But my question is ? are some colors taboo to use. I thought of painting my tanks fire engine red...
Fire engine red is a great color, they'll look sickly grey by the time you hit 30 feet deep.

Good 'ol ROY G. BIV....

Roak (NOT a fan of color, except maybe yellow, which hangs in there 'till about 100 feet, maybe more.)

IndigoBlue
January 11th, 2004, 12:08 PM
But my question is ? are some colors taboo to use. I thought of painting my tanks fire engine red, but i thought I might be mistakin for a secue diver or something. is there any color code on tanks that indentifies the divers skills.

Mike

Black, all black, everything black, black exposure suit, black tanks, black mask, black snorkel, black regs and hoses, this colour identifies a hunter. I have kneeled for countless hours like this, underwater, behind rocks, just a black hole in the water, reflecting no light at all. The fish cannot see you then. Its as if you are not even there, as long as you do not move. You can see wonderous things for moments on end, like this.

Some hunters like to wear camo. But have found that black works even better.

cyklon_300
January 11th, 2004, 12:47 PM
a screaming pink AL80 for an Argon storage bottle...

Stands out like a sore thumb and reduces the likelihood anyone will mistakenly grab it for backgas...the Death's Heads and Ar - Do NOT Breathe signs are a tipoff, too.

I guess you could use martial arts belt color schemes for skill levels...work your way up to brown and then black cylinders. You'd have to be able to cut your cylinder in half with your hand to get the black rating.

mikediveguy
January 12th, 2004, 01:12 AM
I'm looking for links to sites that will provide information or information from members on in-expensive ways yet, effective ways to strip paint, prime and re-paint scuba tanks. The club I belong to is looking to "refresh" our rental tanks as the paint is peeling, have a few different colours and we'd like to standardize the colour. Anyone with information that they think could benifit us, we'd certainly appreciate it. We're dealing with both steel and Aluminum tanks.

Thank You
hey if you're in the base club go talk to the re-finishing boys wink it what we do in comox :)

netdoozer
February 22nd, 2004, 02:47 AM
Found a place nearby that will do them for me at about $25. http://www.hydrostat.com/hydrostat.htm

May just do that to save the effort!

Tom

I wasn't able to get to the above website. I know the above message was posted ages ago, so I wasn't sure if they were still around.

I want to get my aluminun's tumbled. I live close to Deerfield Beach, FL, any suggestions?

Bill

roakey
February 22nd, 2004, 01:07 PM
Bill, use the PM function of this board to send mail to WW.

And, BTW, you have GOT to be the only first-time poster that used the search function before posting, let me send you a big thank you from all the mods!

Roak

Diver_Jan
March 1st, 2004, 02:33 AM
Hi everyone,

I have picked up a used tank. The trouble is, I don't like the color and would like to paint it. Any suggestions how this might be done??? It is a aluminum 63. I was even thinking it might look kind of cool to do an underwater scene with air brush. What do you think? How can I prepare the surface??? Steel Wool, or what? And what kind of paint can I use? Rustoleum???

Thanks for your help!

Jan :54:

Zippsy
March 1st, 2004, 03:30 AM
The color of paint should provide the most camouflage for the place where you will be using it. If it's primarily for driving around the desert, I'd paint it a sandy color. If it's for more of a jungle setting, paint it green. Make sure you use different shades to break up the outline.

Ummmm. Wait a second. Are you talking about a scuba tank? I think I may have made a boo boo. Don't get mad - it just moved your post back to the top of the list :D

DiveTyme
March 1st, 2004, 05:57 AM
You may want to think about using some thing else. Some dive shops will not fill a tank if they have been painted. I have seen some tanks that have like a film on them. I don't know how well it works, just have seen it.

RebreatherBoy
March 1st, 2004, 08:36 AM
The important thing is to remove all the loose paint and any grease film....

You can sand it with just about anything, or you can take it somewhere where they will sand blast it for about $15 or so dollars, so you don't have to deal with it at all. if they sand blast it down to the bare aluminum, you can always spray paint it but those paints are not catalysist cured, so they will not be particularly hard or durable. There are companies that specialize in custom tank paint jobs who will handle the whole thing for you, but doing it all yoruself has to be a labor of love becaus eif you figure out all the countless hours you will spend doing this, cpampared to whatever your salary is for what you do, your time will be wasted.

Rustoleum is primarily a means to inhibit rust on steel products. If you have a steel tank, don't sandblast off the zinc coating which is called galvanizing. Zinc is harder to paint the more fresh it is as it is sorta oily.

NetDoc
March 1st, 2004, 09:34 AM
Just don't let them "bake" the finish on. Heat will destroy the tank's integrity.

Most tanks are already painted... a little custom paint should not detract from it any further, and air brushing sounds great. Have fun and let your imagination plummet. :D

ScubaRon
March 1st, 2004, 10:22 AM
You can also buy an airbrushed tankwrap (http://www.highfeedback.com/page3.html).

Make sure to post a pic of what you end up with!

SDAnderson
March 1st, 2004, 10:41 AM
Painting tanks can take more time and cost more money than it's worth.

The surface needs to be prepped but using steel wool can destory the tank. Little fibers of steel imbed in the soft alumninum and the electrolytic process between the dissimilar metals will cause an oxidization problem. The tank needs to be blasted with a non-metallic substance, which requires special equipment and extreme caution, since the tank is so soft.

A can of Krylon isn't going to do the job, paintwise, either. You need something that will bond well without the use of heat and that can withstand the punishment that tanks receive. Aside from the inevitable dings, the process of filling and emptying tanks means that they stretch and contract repeatedly, which is really hard on coated surfaces.

If the cover-up paint job is detectable, the tank will most likely fail any subsequent visual inspection, essentially necessitating an annual hydro test - and expensive and time consuming process.

Sorry to be such a bummer, but its probably better to accept the tank as it is or sell it and buy what you really want.

nativenarcosis
May 18th, 2004, 05:59 PM
I am setting up a doubles rig using my AL80s. One was already aluminum finish but the other was painted. I of course being the aesthetic beast I am wanted them matching. I then stripped the paint off using paint stripper from Home Despot and finished it off with my DA sander and 400 grit sandpaper. Well, much to my dismay I took my newly finished tank in for a viz and the shop frowned on the process I used to stripped the paint off. Stated that it could have weakened the aluminum. Well.. me not being a metalurgist am coming to the higher power of the board to find out if this is indeed true.. or a farce.
I am thanking you in advance for the help I know I will receive from all you giants of knowledge!!

Curt Bowen
May 18th, 2004, 06:10 PM
I am setting up a doubles rig using my AL80s. One was already aluminum finish but the other was painted. I of course being the aesthetic beast I am wanted them matching. I then stripped the paint off using paint stripper from Home Despot and finished it off with my DA sander and 400 grit sandpaper. Well, much to my dismay I took my newly finished tank in for a viz and the shop frowned on the process I used to stripped the paint off. Stated that it could have weakened the aluminum. Well.. me not being a metalurgist am coming to the higher power of the board to find out if this is indeed true.. or a farce.
I am thanking you in advance for the help I know I will receive from all you giants of knowledge!!


I have sand blasted a couple AL tanks in the past, seemed to work fine

cyklon_300
May 18th, 2004, 06:16 PM
after stripping an Al80 with Aircraft Stripper and then HAND finishing with 600# wet/dry was this...

The shop threw a hissy, questioned me at length about the procedures I used, and demanded a hydro. No big deal, just do it and fill it.

To satisfy my curiousity, I called Luxfer directly and spoke to a technical specialist. He stated that as long as the paint was removed 'without power tools' and passed inspection, it was good to go. Mine passed and I've had it filled at least 125 times since.

Depending on how you used the sander and what kind of temperatures were generated in the process is the key to whether you made a garden gong or not.

Drew Sailbum
May 18th, 2004, 09:03 PM
If you generate sufficient heat, you will change the metallurgy of the cylinder and it is no longer capable of holding up to the high pressures fo scuba service. I would tend to assume that a power sander would be capable of generating sufficient heat in localized spots to make a cylinder suspect.

Generally, if you used a power sander to strip a coating, I would not pass the cylinder on visual inspection.

nativenarcosis
May 18th, 2004, 09:14 PM
If you generate sufficient heat, you will change the metallurgy of the cylinder and it is no longer capable of holding up to the high pressures fo scuba service. I would tend to assume that a power sander would be capable of generating sufficient heat in localized spots to make a cylinder suspect.

Generally, if you used a power sander to strip a coating, I would not pass the cylinder on visual inspection.

This is a pneumatic dual action sander that I use on the fiberglass on my Corvette. Heat is definately not a problem so I should be in the clear..

Drew Sailbum
May 19th, 2004, 09:22 AM
This is a pneumatic dual action sander that I use on the fiberglass on my Corvette. Heat is definately not a problem so I should be in the clear..
As the visual inspector, I cannot tell what means were used to strip any coating. I can usually see tell-tale marks which come from a power sander.
You don't have to remove much metal to condemn a cylinder. In a typical 3AL cylinder, the removal of greater than .030 inches of metal in any one spot is enough to condemn the cylinder. If a cylinder was sanded and metal was removed, it may be difficult to determine where the original baseline was to measure pit depth.

cra2
June 23rd, 2004, 05:51 PM
I just got a couple of used aluminum 80's.
A) how do I clean 'em up - get all the stickers, scuffs off, etc?
B) can I paint them? If so, how?

Thanks,
cra2

DA Aquamaster
June 23rd, 2004, 06:17 PM
Old VIP stickers come off with a little heat. The key word here is "little. Use a hair dryer, not a heat gun, as a heat gun is too much heat and anything over 325-350 degrees is bad news for the heat treated alloys used in aluminum scuba tanks.

A razor blade can also be used to remove stickers with some 409 or WD40 to remove the remaining goo.

Painting is possible but surface prep is important. You do not want to use power tools to strip the old paint as it can generate excessive heat. You also want to use a stripper that is compatible with aluminum. Soda based strippers used for aircraft repainting are ideal.

Painting itself requires an appropriate self etching primer and preferably a two part paint such as imron or MTK that is fairly resistant to scrapes and dings. That type of paint will require the use of a suitable paint gun. There may be some paints out there in a spray can that hold up well, but I have yet to encounter one. A mild scuff sanding can help adhesion but mild is the key word as you do not want to introduce scatches that will reduce the strenght of the tank.

You also under no circumstances want to heat treat the paint as the temps involved can weaken the tank.

Be advised that newly painted Al tanks make dive shops nervous as more than one tank has exlpoded after the paint was baked in a paint boot. They will require a description of how you repainted the tank at a minimum and at worst may require a fresh hydro test in addiiton to a VIP. It's a good idea to talk to your LDS of choice about your plans first and maybe get their suggestions. You then will have a better chance of convicing them that you did not do something stupid with the tank once it is painted.

I have often considered just using a preparation like Zing on a tank to clean and brighten up an old aluminum tank. It works great on aluminum boat hulls but boat hulls contain very little pressure and I have never heard whether the acids in the Zing preparation could potentially weaken the walls of the tank.

FLL Diver
June 23rd, 2004, 09:03 PM
Found a place nearby that will do them for me at about $25. http://www.hydrostat.com/hydrostat.htm

May just do that to save the effort!

Tom

Tom - did you ever get your tanks done there? How'd they turn out?

Marc

nativenarcosis
June 23rd, 2004, 09:23 PM
After doing my AL80s.. My recommendation is this:
Chemical strip (keeps the viz guys happy. They don't like seeing roughed up tanks.) And then hit them with some Mother's polishing compound. What I figure if it is good enough for my Corvette's wheels it will suffice for my AL80s. They now look MARVEE. Pardon the vainess of having nice and shiney tanks but I cannot help it.

mstevens
June 13th, 2005, 11:50 PM
B^cubed:

...I are an Fightin' Texas Aggie and proud of it! I can even count to twenty if I take my dive booties off!

Hmm. You must never have worked on Bonfire...

Surelyshirly
July 21st, 2006, 06:21 PM
Have brushed aluminum tank and wish to air brush or paint a custom design on it, simple but would definately make it mine. What kind of paint should I use and should I then clear coat it? If it chips off it chips off and then I will touch it up

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