Why did Horse Collar BC's fade away?

[Angelo Farina]

I have an old HCBC that's getting up there in years. The stitching on the external bag is fine but the internal air bladder is getting old. The whole thing has been updated with a shoulder dump valve, a power inflator and a parachute type harness. I need to replace the internal air bladder but they haven't been made in quite a few years.

So, I'm going to make my own! I'll take the old one apart as a pattern and have a supplier for the Polyvinyl C. material and the adhesive but don't know what gauge materiel to use. I could measure the old one once I cut it apart but would like to have everything on hand once I start the job. Does anybody know how thick the internal air bladders are?

Same happened to my very old Fenzy (the one you see in my avatar).
I inserted a new bladder. I simply used an annular PVC floating device previously used by one of my children.
Something like this:

 

[Waterwulf]

I guess that you take your parachute with you if you go on a commercial plane aswell? Imagine the plane goes down and you don’t have one with you.

Actually, I don't like big airplanes and try to get out of them as fast as possible. Funny thing is, I've taken off in one more times than I've landed in one! I usually leave them mid-flight.

 

[jadairiii]

have a supplier for the Polyvinyl C. material and the adhesive but don't know what gauge materiel to use.

I dont think a "glued" bladder will hold. I dont know of any BC manufacturer that glues their inner bladders. Why not just buy a new one, there are companies that still make them.

It is a "life saving" device. Why half-ass it?

 

[Gone for diving]

An inner tube will work fine.
Go to your local agriculture store,
You can get fat tube with smaller diameter,
I have made a few wings for my old plastic back plates, with tire tubes and don't even cover them.

This is a small one I don't use anymore.

 

[Waterwulf]

Angelo....Thanks, I think I'll pass on the kids floaty but only because it's the wrong shape! Otherwise, it would have been perfect! Besides, my Grand Kids would probably steal it out of my BC so they could use it in the pool! lol

Judairiii....I have not been able to find one that will fit a Seaquest. They haven't been available for years. There is one company that makes one but it's not a duplicate and would have to be altered. It's just easier to make my own.

Gone for diving.....Inner tube rubber is to thick for an internal bag. Plus, when it gets old, it tears. Polyvinyl Chloride comes in different types for different uses. What I use has "Plasticers" in it to make it flexible and anti UV additives. It's basically waterbed materiel.

Yes, a glued bladder will hold just fine. Modern BCD rigs have internal bladders that aren't really separate pieces. It's all one piece. The seams are sewed and "painted" with a substance to waterproof and air proof them. The material is backed with nylon or something similar and it's pretty tough.

Most of the old Horse Collars had a separate internal air bladder. You could remove it from the external cover, which was usually nylon. (After removing the fittings) The seams on those were only glued because the material by itself wasn't strong enough for sewing. It's the same stuff waterbeds are made out of. (Those are glued too and they take a lot of abuse) The internal air bladder held the air and the external bag held the air bladder and fittings.

The materiel is Polyvinyl Chloride. The adhesive is specifically designed for it and is incredibly strong but it's not the only bond. I have a free style heat sealer that I will run over the seams too. (Free style means I can go around corners with it) I have a fully equipped shop and have done this type of work before. I have no doubts that my fabrication abilities are as good or better than most production facilitates. Plus, my quality control is way better than theirs. "Good enough to sell" ain't good enough for me to use!

The process is straightforward. The old one aka the donor is cut apart so it will lay out flat to trace the pattern onto the new material. The new pieces are cut out and marked front or back. Then I use a die cutter to cut the holes in the front part. The rear part has no cut outs. Forty five mils. for the purge valves and six mils. for the CO2 inlfator. Then tiny slits are cut around the inner edges of the holes so they can be folded over. The slits are folded over and glued in place. Now the holes are the required fifty mils. for the purge valves and eight mils for the inflator. The holes are double thickness around the edges. Factory doesn't do that but I think it's adds strength.

Then, all but one purge valve hole are sealed over with silicone patches on what will be the inside of the bladder. I use silicone for that because it sticks good to the Polyvinyl Chloride but it's easily peeled off. The edges are lined up and overlapped by about twenty five mils. The adhesive is laid in and cured. Then I run over the new seam with the heat sealer and trim the edges. It's ready! Except it's inside out.

I have a vacuum former that I use to turn it right side out. The bladder is hooked up with the one opening exposed to the vacuum. Slow vacuum is applied and the whole thing gets sucked thru the hole and now it's right side out. (It looks like some kind of creature sliding out of the hole!!) The seams are on the inside. The silicone patches, now on the outside are peeled off, the new bladder is inserted into the outer bag and the fittings installed and then I do a pressure test. A few PSI and twenty four hours later, I have a new Horse Collar BC.

This time, I'm going to sew on some more pockets and attachments points to the outer bag while I have it all apart. I guess I'm going to have to measure it after I cut it apart since I don't remember what it was and I can't find that information. If anybody is interested, I can take photo's of the process and post them here.

 

[Gone for diving]

So, I'm going to make my own! I'll take the old one apart as a pattern and have a supplier for the Polyvinyl C. material and the adhesive but don't know what gauge materiel to use. I could measure the old one once I cut it apart but would like to have everything on hand once I start the job. Does anybody know how thick the internal air bladders are?

Yes, a glued bladder will hold just fine. Modern BCD rigs have internal bladders that aren't really separate pieces. It's all one piece. The seams are sewed and "painted" with a substance to waterproof and air proof them. The material is backed with nylon or something similar and it's pretty tough.

Most of the old Horse Collars had a separate internal air bladder. You could remove it from the external cover, which was usually nylon. (After removing the fittings) The seams on those were only glued because the material by itself wasn't strong enough for sewing. It's the same stuff waterbeds are made out of. (Those are glued too and they take a lot of abuse) The internal air bladder held the air and the external bag held the air bladder and fittings.

The materiel is Polyvinyl Chloride. The adhesive is specifically designed for it and is incredibly strong but it's not the only bond. I have a free style heat sealer that I will run over the seams too. (Free style means I can go around corners with it) I have a fully equipped shop and have done this type of work before. I have no doubts that my fabrication abilities are as good or better than most production facilitates. Plus, my quality control is way better than theirs. "Good enough to sell" ain't good enough for me to use!

The process is straightforward. The old one aka the donor is cut apart so it will lay out flat to trace the pattern onto the new material. The new pieces are cut out and marked front or back. Then I use a die cutter to cut the holes in the front part. The rear part has no cut outs. Forty five mils. for the purge valves and six mils. for the CO2 inlfator. Then tiny slits are cut around the inner edges of the holes so they can be folded over. The slits are folded over and glued in place. Now the holes are the required fifty mils. for the purge valves and eight mils for the inflator. The holes are double thickness around the edges. Factory doesn't do that but I think it's adds strength.

Then, all but one purge valve hole are sealed over with silicone patches on what will be the inside of the bladder. I use silicone for that because it sticks good to the Polyvinyl Chloride but it's easily peeled off. The edges are lined up and overlapped by about twenty five mils. The adhesive is laid in and cured. Then I run over the new seam with the heat sealer and trim the edges. It's ready! Except it's inside out.

I have a vacuum former that I use to turn it right side out. The bladder is hooked up with the one opening exposed to the vacuum. Slow vacuum is applied and the whole thing gets sucked thru the hole and now it's right side out. (It looks like some kind of creature sliding out of the hole!!) The seams are on the inside. The silicone patches, now on the outside are peeled off, the new bladder is inserted into the outer bag and the fittings installed and then I do a pressure test. A few PSI and twenty four hours later, I have a new Horse Collar BC.

This time, I'm going to sew on some more pockets and attachments points to the outer bag while I have it all apart. I guess I'm going to have to measure it after I cut it apart since I don't remember what it was and I can't find that information. If anybody is interested, I can take photo's of the process and post them here.

Seems like you have it all covered,
all you need is a dial vernier, to measure thickness,

Take any bladder measure it, divide by 2 and you will know the material thickness,

 

[Angelo Farina]

The shape of the bladder is quite irrelevant. It will adapt to the containing bag.
It must just be a little bigger than the container bag.
So, when overfilled , it will fully use the internal volume of the containing bag, without being stretched and risking to explode.
There is no need that the shape of the bladder is conformal to the shape of the containing bag.
I also used a tube for tires, it is heavier but more elastic the PVC annular.

 

[Gone for diving]

I also used a tube for tires, it is heavier but more elastic the PVC annular.

Yeah just be careful with no safety vent...
Power inflator can really inflate it...
Oral inflate you can never stretch it...
That why I don't use the one in the picture.... was to small to orally inflate, for decent lift.

 

[Angelo Farina]

Yeah just be careful with no safety vent...
Power inflator can really inflate it...
Oral inflate you can never stretch it...
That why I don't use the one in the picture.... was to small to orally inflate, for decent lift.

My tubr was inside a fixed-volume container bag. And it had an overpressure valve. The tube wss not very thivk and heavy and oral inflation was easy.
The tube was large enough for filling the container bag with stretching significantly, so oral inflation was possible with little effort.

 

[dead dog]

I took my first underwater breath in 1968. I took a course in Florida but it was just to be able to buy air from local shops. In 1972, we moved from the coast of Florida to Southern Germany. Because of my previous underwater experience, I was able to sign on with a Search and Rescue Team, although we never rescued anybody... just body recovery. In 1974, we moved back to Florida and I discovered that my certifications were no good anymore so I had to take a real Scuba diving course! I signed up for a NAUI course put on by a local dive club. (Hurlburt Dive Club)

Up until that point in my underwater adventures, I had never seen or even heard of a Buoyancy Control Vest. Buoyancy control for me and everybody else that I dove with, consisted of a bag of lead weights attached to the anchor line. You guessed what you needed, jumped in, went to the weight bag on the anchor line and took or left lead as needed. That was our buoyancy adjustment!

However, at the dive course, one of the instructors had a vest that he could inflate or release air as needed to adjust his buoyancy on the swim! He'd stolen it from the Air Force and modified it. I wanted one! Then I started seeing them in dive shops so I bought one. It was wonderful! It was the greatest thing since canned air! I forget the brand but it was a Horse Collar type with a purge valve down low and an oral inflator on the chest. It also had a CO2 inflator which I thought was neat. I used that thing all over the Gulf Coast of Florida and most of the assorted springs and caves inland.

Then life happened and I stopped diving for a while. When I came back to it, I discovered that the Horse Collar BC was no more. They call them "Snorkel Vests" now and they're really nothing but toys. I took a refresher course to get myself back in diving shape. I used their gear and had to wear a jacket type BCD with the tank attached to the back. It had a neat button to automatically inflate the vest or deflate it.

That was the only thing about it that was any good in my honest opinion! The rest of it sucked!!!!! It had a lot of drag! I felt like I was pulling a sail behind me! I started trying to learn how to make it work for me and got good enough to satisfy the instructor but....it sucked! I hated it! Besides the underwater drag, it kept trying to drown me! It kept pushing my face into the water, even with minimal air inside. Back in about 1975, my girlfriend and I surfaced in a squall and got separated from the dive boat in the waves. We had to float for an hour or so before the boat found us. We would have drowned using a modern BCD! As it was, we just inflated our Horse Collar BC's, held hands and floated peacefully up and down the waves until we heard the boat blowing the horn looking for us.

In present day, I managed to locate a Seaquest Horse collar type BC that was in perfect shape and upgraded it with a new corrugated hose/inflator button. My only complaint about it, is that there's not much pocket space and hardly any gear attachment points. I can live with that.

So! Why did the Horse Collar Buoyancy Compensator stop getting used? Why is the new style jacket type better? In my very un-expert opinion:
The H/C B/C allows the diver to dump their weights and tanks without loosing their flotation. It is much less drag underwater and will not drown you if you're unconscious. The H/C B/C adjusts my buoyancy underwater perfectly and I can inflate it with air from the tank or from my lungs. I have a purge on the lower end and a pull purge on the hose.

What can a new stype jacket BCD do better besides have more pockets and attachment points?

The horses keep getting bigger and bigger, and could no longer get their head through the opening of the horse collar.