Tank height strap for backplate?

[AdivingBel]

On the first dive of the day (when the cambands are dry) I've gotten into the habit of unthreading the outside loop (only) of the cambuckle. I give it a tug and then lift up on the buckle enough to hold tension while I rethread the loop. Then using the extra band length for leverage, I close the buckle. Since I started doing that, I've never had a camband come loose (it's a plastic cam buckle, no problems). I also have a lower band with a scubapro type buckle. I don't worry about getting it extra snug (it stays snug enough) as it's really there to keep the tank from twisitng and loosening the top band. YMMV

 

[tbone1004]

Thanks for the correction, never used a single tank system from DSS, so was going off of the product links. If the wedge blocks are working like is mentioned above, they should mitigate the need for pads on the bands themselves unless you are wanting to protect the paint if you're using metal cam buckles, with plastic it doesn't matter, but you can't crank down quite so hard, but my cam bands are usually "snug" but I've never fought to close them. Methinks this is a gear setup problem and once you have the cam bands set appropriately, then you really shouldn't have to adjust them that often.

 

[ams511]

If I find a easy and clean way to do this, I will definitely give a try.

If the top mounting hole of your plate is clear you can try this: Make a loop out of cord. Pass it though the hole on the plate and then though the middle of the loop. now the loop is attached to the plate. Hang the loop on the valve or tank neck and it should help with positioning the tank straps. When done remove it so you don't get caught on anything. That is the basic idea. I am sure it can me modified to be better.

Related, a while ago there was a thread where someone was using a SP style for one of the bands and a regular style for the other. From memory they were doing this to help with positioning. Maybe someone else remembers how it was done.

---------- Post added March 26th, 2015 at 09:42 AM ----------

But for whatever reason (cost?), DSS prefers plastic cam buckles, and so includes the wedge block to make up for the inability to crank down hard on the buckle.

Only Tobin can say why he used plastic rather than metal however plastic buckles do have some advantages. There are lighter than metal and don't scratch the tank. Also they are very durable. The metal buckle may be able to cause a pinch flat also.

I admit metal is more durable, but most recreational BCs I have seen use plastic buckles and there does not seem to huge problem with broken buckles.

 

[Lorenzoid]

. . .
I admit metal is more durable, but most recreational BCs I have seen use plastic buckles and there does not seem to huge problem with broken buckles.

There's no problem with broken plastic buckles on recreational BCs because there is flexibility built in elsewhere. But there's nothing flexible about an STA-less metal backplate. You've got the cambands threaded through slots in the plate and the buckles to tighten them, and that's it--there is no "give" in the backplate. Hence the need for wedge blocks. (Not "explaining" to you, just restating the situation.)

I've been under the impression that metal buckles are more common on BP/Ws. But that may be because most BP/Ws require an STA, and perhaps the STA provides the bit of flexibility that's needed to keep the cambands under tension. (I don't have much experience with STAs, either.)

 

[ams511]

I picked up somewhere along the way that you need to wet your cam bands and then make sure they are really tight. And, as I explained before, I have often not been able to wet my cam bands first, so I've always been paranoid about getting them EXTRA tight when dry. Maybe the specific rig setup I have I just don't need to work THAT hard at it.

You dive instructor should have told that the cam bands should be wet before mounting on a tank. I was told the material in the straps expands slightly when wet and the wetness helps the strap move down the tank. Remember, unlike most recreational BCs you have two cam straps to keep the tank in place. So there is no need to be paranoid.

 

[stuartv]

However, I am wondering if the BC was assembled correctly. My experience with eBay used BP/W is that they are usually misassembled in some way.

Well... I bought it off CL, directly from the original owner. Then I bought new webbing and re-rigged it to fit me. Then I traded the original size M BP for a size L BP and moved all my rigging from the first BP to the second.

Before I did it the first time, I read/watched all the info available on the DSS site and some other sites (DGX? GUE?) on how to assemble a Hogarthian rig. There is a difference between Tobin's directions and the DIR directions on where to position the waist belt buckle and I did it Tobin's way the first time, then did it the DIR way the second time. So I am pretty confident that it's assembled correctly.

---------- Post added March 26th, 2015 at 02:07 PM ----------

You dive instructor should have told that the cam bands should be wet before mounting on a tank.

Yes, they did. And I do when I can. But, my limited experience so far has been mostly diving off boats. And that has meant assembling my rig for the first dive while the boat is under motor out to the first site. Which has meant that it was not practical/safe for me to wet the cam bands before assembling my rig for the first dive.

How do you wet your cam bands before the first dive, in that situation?

 

[ams511]

There's no problem with broken plastic buckles on recreational BCs because there is flexibility built in elsewhere. But there's nothing flexible about an STA-less metal backplate. You've got the cambands threaded through slots in the plate and the buckles to tighten them, and that's it--there is no "give" in the backplate. Hence the need for wedge blocks. (Not "explaining" to you, just restating the situation.)

I've been under the impression that metal buckles are more common on BP/Ws. But that may be because most BP/Ws require an STA, and perhaps the STA provides the bit of flexibility that's needed to keep the cambands under tension. (I don't have much experience with STAs, either.)

Perhaps BC construction has changed over time but the BCs I am familiar with don't have a lot of flexibility. The cam straps are run through a hard plastic backplate. The plastic may flex a bit but not by much. I doubt it is very compressable. My old Beuchat BC was assembled this way as well as the Scubapro BCs I learned on. Most of the others I have seen look to be assembled the same way.

An STA provides no more flexibility than a plate does. While most manufacturers do sell a complete system I don't think most are sold that way. Probably most sold are a mix and match of items except for DSS and Halcyon.

---------- Post added March 26th, 2015 at 10:23 AM ----------

How do you wet your cam bands before the first dive, in that situation?

Usually the op has a rinse tank set up near the boat. I just use that if available.

 

[stuartv]

Usually the op has a rinse tank set up near the boat. I just use that if available.

Near the boat, or ON the boat?

I have eyed the rinse tanks on the boats I've been on and, generally, the one that isn't "cameras only" has been too small to dunk my whole rig. And disassembling to something that would fit wasn't really an option. So far, I have mostly been out on medium-sized or smaller boats.

Thanks for all the advice (from everyone). Next time I dive, I think I will just start by trying dry bands (if not convenient to wet them) and just closing them as they're set and see if I end up having any problems with my tank slipping. If I DO have a problem with a tank slipping, it's MOST likely going to be when I'm getting in or out of the water, right? Probably when I'm getting out and the bands are now wet and have relaxed? Not actually when I'm in/under.

 

[ams511]

Near the boat, or ON the boat?

I have eyed the rinse tanks on the boats I've been on and, generally, the one that isn't "cameras only" has been too small to dunk my whole rig. And disassembling to something that would fit wasn't really an option. So far, I have mostly been out on medium-sized or smaller boats.

Thanks for all the advice (from everyone). Next time I dive, I think I will just start by trying dry bands (if not convenient to wet them) and just closing them as they're set and see if I end up having any problems with my tank slipping. If I DO have a problem with a tank slipping, it's MOST likely going to be when I'm getting in or out of the water, right? Probably when I'm getting out and the bands are now wet and have relaxed? Not actually when I'm in/under.

Near the boat, usually on the dock. You only need to wet the straps not dunk the whole rig.

 

[tbone1004]

you have your own tanks don't you? Just wet them and set them the night before.... take them off and you're good to go