Wrestling with bouyancy issues on G10/Ikelite

[WOODMAN]

I have a G10 in the Ikelite housing with dual Ikelite ds125 strobes, and boy does this thing get heavy underwater. I can feel it in my wrists after a couple of dives from constantly holding the thing level, as it wants to nose downwards most of the time. I have been researching this for awhile now, and some sort of floats on the strobe arms looked good at first. I tried pool noodles on the arms, but they crushed at depth, of course, and were useless. I obviously need noncompressible foam of some type. I have been looking at the Stix floats, but then I noticed they make a band of floats that are supposed to go around the lens port on a housing, and I got to wondering if this might work around the nose of those heavy DS125's? The nose housing is about 3 3/4 inches in diameter, and I wonder if a band of those floats might be coaxed into clamping onto the front of each of the darn things? I could pull off some of the floats if it proves too much, but I sorta doubt that will happen. Any ideas on this harebrained scheme? Any input cheerfully accepted. (Sorry I couldn't put in a link to Backscatter for those Stix floats, but I have not yet figured out how to insert links. Yeah, I know- it's probably simplicity itself, but I haven't found the tutorial on this yet.) Again, any help will be greatly appreciated. (I suppose I could get a couple of those giant tanky plastic float arms from Inon, but somehow those things look mighty cumbersome, although I suppose no worse than what I am contemplating. Thoughts?) Woody

 

[Banon]

My wife uses a Canon G11, Canon housing, ULCS base/arm, with an Inon Z240 strobe. The strobe is negatively bouyant and put stress on her arm, trying to tilt the camera forward as you describe in your post. We got her a single bouyancy arm and it solved the problem.

My guess is that you can solve your issue with a lot of different approaches, but bouyancy arms will be the cleanest solution. I haven't held your exact setup, but you might think about how leverage and bouyancy would combine. Normally the arms are positioned at close to the highest point of the setup, which means they provide lift which naturally tilts the nose back up. No need to add a float to the nose of the housing, in fact since the nose is near the bottom of the setup, it might cause other imbalance issues unless offset by bouyancy elsewhere.

If you already tried the pool floats and they worked well for you in shallow water when tied to the arms, then you are almost guaranteed that floatation arms like Styx, ULCS, or others will be a viable option.

Have fun!

Banon

 

[skynscuba]

Get the 6# Divinycell foam, and make your own. I did this to balance my -10oz focus light, and also put some on each stobe arm. I was going to do it for my wife's wide angle lens, but didn't get to it yet. Get the 1" thick. Very easy to cut/shape, and you can glue it with the PVC cement like you use on PVC plumbing. I painted mine black with a few coats of spray plastic, and tied them on with small bungee cord.

DIVINYCELL FOAM PVC from Aircraft Spruce

It will provide about 0.52 ounces of flotation for each cubic inch.

 

[WOODMAN]

Get the 6# Divinycell foam, and make your own. I did this to balance my -10oz focus light, and also put some on each stobe arm. I was going to do it for my wife's wide angle lens, but didn't get to it yet. Get the 1" thick. Very easy to cut/shape, and you can glue it with the PVC cement like you use on PVC plumbing. I painted mine black with a few coats of spray plastic, and tied them on with small bungee cord.

DIVINYCELL FOAM PVC from Aircraft Spruce

It will provide about 0.52 ounces of flotation for each cubic inch.

Most interesting- I knew there had to be something like this out there, and I knew someone here would know about it. Man, that stuff is expensive, though, but I can sure see the possibilities. The 6# stuff you say? This might just work. Let me "noodle" on it for a bit. Thanks for the idea. Woody

 

[skynscuba]

Most interesting- I knew there had to be something like this out there, and I knew someone here would know about it. Man, that stuff is expensive, though, but I can sure see the possibilities. The 6# stuff you say? This might just work. Let me "noodle" on it for a bit. Thanks for the idea. Woody

That $18 (plus shipping) 10x12x1 piece gives 3.9 pounds of buoyancy. I don't have a rig as heavy as yours, but I did mine and my wife's, and still have a bit left over. You don't have to make it neutral, just easier and less tiring to use. You will probably find that you don't want the bulk of foam that would be required to totally balance the rig.

 

[WOODMAN]

Well, I just got that chunk of Divinycell foam, and migawd! It is as dense as a pine board! Lets's see- I have enough to make 2" diameter floats for each of my 4 strobe arms, plus a nice chunk to clamp under the housing. Woohoo, I think this will work. Now comes all the cutting and crafting. Black plastic-adhering paint you say? Gotcha. The small bungee cords seem somehow inelegant to me, but for the life of me I can't think of a better attaching system, so okay. At least this whole thing will be readily dismountable, so I can get it off to allow me to pack the camera system in it's travel case, which already has only about 3 square inches of available space left over when the camera is in it. That was the problem with all the other systems I looked at, as they took up too much space and required me to break down the arm assemblies to get them off (which isn't particularly easy:mooner, or else the arms were the floats themselves and wouldn't fit in my travel case. This way, it all comes off fairly easily and can pack separately if necessary. I just wish I had a better way to keep those float halves together over the strobe arms other than bungee cords. Oh well, progress marches on. Stay tuned for developments. Woody

 

[gert7to3]

Skynscuba,

Great post on that aircraft materials source.

For cheap, tough flotation you might try wine corks. The new plastic ones especially, since they're totally sealed. Extractor holes can be plugged with silicone.

 

[gert7to3]

You could use zip ties (wire ties) to hold the floats together. They are cheap enough to be cut away and replaced. There are some thicker models which are reusable. The little ratchet can be opened, freeing the strap.

Your last post popped in while I wrote my previous post.

 

[WOODMAN]

Okay, here is an update. It took me awhile to finish this, but it came out pretty well, I think. I am gonna try to post pictures of the assembly below. Zip ties were the obvious solution, and I cannot believe that I didn't think of it myself. I have not gotten this rig wet yet, so I am unsure how much help this will be. A question that I should know the answer to, but it escapes me at present:blush:... Will this setup show more lift in salt water than fresh, or less? I can probably get it into a pool here to test basic flotation, but how will that correspond to salt water? (Dammit, I'm supposed to know this..) Anyway, here are the pictures of the rig and a closeup of the arm floats. [I also posted the pictures in my photo gallery if this doesn't work] I managed to use every bit of that sheet of foam for this, other than cutting and sanding losses. Woody

 

[WOODMAN]

Another update- I finally got this rig into a pool, and lo and behold, too much buoyancy! (at least in fresh water...) So I removed the bottom float from under the camera body, and now the rig is just a few ounces negatively buoyant, and will slowly sink if I let go of it. That is just about perfect, to my way of thinking. Now if it will continue to do that in salt water, we will just about have this thing licked. Woody