Vintage Double Hose

Anyone have a 1st gen. Healthways Scuba parts diagram or repair manual. Didn't see one in the M&C section. Didn't really need a HW Scuba but I now have one so I figure I might as well fix it up to play with. Thanks. Mark

Never mind. Answered my own question
Amazing what a simple Google search will give you in a zillionth of a nanosecond.

Never mind. Answered my own question Amazing what a simple Google search will give you in a zillionth of a nanosecond.

What is up with the funky exhaust system anyway? Why the diaphragm over the inside of the exhaust horn?

The exhaust diaphragm (#28) is the Achilles heel of that regulator. Most everybody just seals off the opening in the can where #28 should go and use a duckbill of sorts. The next model, SCUBA DELUXE, went to a good mushroom valve design.

simonbeans wrote: ↑

Thu Aug 02, 2018 5:18 pm

The exhaust diaphragm (#28) is the Achilles heel of that regulator. Most everybody just seals off the opening in the can where #28 should go and use a duckbill of sorts. The next model, SCUBA DELUXE, went to a good mushroom valve design.

That's what I was thinking. Any reason not to just weld a piece of metal over the opening where #28 fits and install a duck-bill on the horn? Or is there some pressure-related reason for having a rubber diaphram of some sorts?

Now that I have the exhaust diaphragm off I can see there is very little space between the inside end of the horn and the inside wall of the diaphragm.  Guess it needs the flex room to expand slightly on exhalation so exhaled air can get out of the metal horn and out through the holes in the can. The exhaust diaphragm on there is in pretty decent shape but don't think i'll trust it. I'll make one out of a silicone sheet or something.



The more I look at this thing the more stupid I think the design is. Don't get me wrong, I actually like the aesthetics of the reg but the whole exhaust diaphragm blocking a giant hole open to the ocean/lake/river/pool, etc... which empties into the air delivery chamber seems like a leak, choke, gasp, gag, free ascent waiting to happen. I'm probably concerned over nothing and I'm sure the reg works just fine as thousands were likely sold and used. I also don't mean to denigrate Healthways afficianados. I have a gold label that I love. I just don't get why some design engineer thought this was a good idea. (And borrowing from Bob Newhart, for Healthways afficianados,  "denigrate" means to "put down.") 

P.S. Now that I think about it , the exhaust mushroom valve in the 2nd stage of a single hose reg is a lot flimsier and that seems to hold back the sea pretty well.

That's a real nice looking Scuba. I now have 4-5 of them, but only one looks as nice as yours!

There is a long thread on Vintagescuba.proboards.com concerning this regulator and people's mods and solutions to the exhaust diaphragm problem. Let me head off the inevitable snarky comments: One does not have to be a believer in those solutions or the folks who post there in order to glean a lot of information about the Scuba.

One should be well aware of the problem of having a large hole leading from the ocean/lake/river, etc., into the air side of the regulator. A small failure of the diaphragm can have catastrophic consequences if flooding occurs. I have had a small leak around the flange cause the regulator to fill up enough to make breathing difficult near the end of a dive. Since I carry a backup regulator on my rig when I dive single stage regs, this wasn't serious.

Sealing the perimeter of the flange and the membrane is crucial. RTV will work. Then, testing the seal around the diaphragm is also crucial. Testing can be done by duct taping the exhaust holes, clamping a hose on the exhaust horn and filling it with water. Leave it hanging for a while. Any leak around the flange or pinhole in the diaphragm will show itself.

People have used many things to serve as a membrane with success. Silicone sheet cuts too easily , and the wire clamp will likely cut it when you try to get the thing over the flange. Butyl innertube rubber works well, but I think it might deteriorate fairly quickly. Others have used Nitrile gloves, etc.

Out of more than a dozen Scubas I have owned, every one of them showed evidence of water intrusion and the effects of water sitting inside the air chamber. This leads me to suspect this has always been a problem with this reg, even when new and supple diaphragms were available. Frequent checking is wise.

I like the Scuba for its slim profile and it's simplicity. They breathe pretty well if you use a Hope-Page or USD loop.

Thanks for the input Phillip. It appears there are many ways to tackle the exhaust diaphragm issue, none perfect but some workable. BT from Texas has given me some great advice. My diaphragm is old but in pretty decent condition. I've been looking at ways to use it to cast a two-part silicone mold and then use liquid silicone to cast a new exhaust diaphragm (using a release agent so the two silicones do not stick). During my research I had flashbacks to silicone polymer chemistry questions in college. Still researching.

Mark

I have been making dipped silicone duckbills for the Scuba. I use a turned wooden plug and dip and brush the liquid silicone onto the plug. I have had good success with this method.I'd really like to discuss the casting process for an exhaust diaphragm with you. Having a mold made will cost far too much for the 2 dozen diaphragms you'd sell, so I'd love to see some solutions...

Vancetp wrote: ↑

Sun Aug 05, 2018 7:54 pm

I have been making dipped silicone duckbills for the Scuba. I use a turned wooden plug and dip and brush the liquid silicone onto the plug. I have had good success with this method.I'd really like to discuss the casting process for an exhaust diaphragm with you. Having a mold made will cost far too much for the 2 dozen diaphragms you'd sell, so I'd love to see some solutions...

Phillip,

I'm in the midst of researching the casting process right now. I have a pretty good idea of what I want to do but no one seems to sell a small kit that will do exactly what needs doing for this particular purpose. As a result, if I go this route I'll have to source from different suppliers (e.g., clay, catalyst, reagent, release agent, mold form, etc...). I'm game to try but I'd like to not spend a zillion $ doing so. I'll post my work if I decide to go this route. If you want to talk email me your phone number. Mark

Really, the way to go on this is to find a good membrane material and a good way to seal the flange. Casting one or two isn't efficacious. Unless you can find a simple method!

Vancetp wrote: ↑

Sun Aug 05, 2018 9:42 pm

Really, the way to go on this is to find a good membrane material and a good way to seal the flange. Casting one or two isn't efficacious. Unless you can find a simple method!

BT has already figured that out. It involves the upper part of panty hose, liquid silicone, an oring and a pissed-off wife. Just saying.

That sounds like a very simple way of doing something I have already done in a WAY more complicated manner and probably not as well. I have tried the o-ring, and the ziptie (not even close), and the fishing line. My Eastern European regulators have a lot of coiled fishing line holding hoses and mouthpieces and duckbills on. It might work out eventually, with practice..

Phillip,

I found and read that other thread you were talking about on HW Scuba regs. Actually very interesting and informative. Thanks. Mark