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ScubaLawyer
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Question on reproduction silicone diaphragms

Tue Aug 07, 2018 12:28 pm

I have a question for my own nefarious purposes. What kind of silicone compound is used in casting reproduction second stage diaphragms? It certainly ain't 100% silicone aquarium cement or Home Depot caulking silicone. Appreciate any info. Thanks. Mark
"The diver who collects specimens of underwater life has fun and becomes a keen underwater observer. .. seek slow-moving or attached organisms such as corals, starfish, or shelled creatures." (Golden Guide to Scuba Diving, 1968) :D

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Chris
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Re: Question on reproduction silicone diaphragms

Tue Aug 07, 2018 1:02 pm

I was curious about that yesterday while skimming the post on making your own aqualung.
Formerly tripplec. Decided to use my real name since you guys aren't a bunch of flaky internet trolls.

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antique diver
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Re: Question on reproduction silicone diaphragms

Tue Aug 07, 2018 1:12 pm

tripplec wrote:
Tue Aug 07, 2018 1:02 pm
I was curious about that yesterday while skimming the post on making your own aqualung.
The Permatex "Flowable" Silicone would not have sufficient strength to work well by itself. It needs the support of the nylon mesh (like that found on the thicker upper part of pantyhose), and it will still remain very soft and flexible. It is probably not the best Silicone to be used as regulator diaphragms, but it is readily available at auto supply stores, and easy to spread with your fingertip. I have used it to make diaphragms for single hose Aquamatics, Healthways Scubastars, Voit Trieste double hose regs and now for the Aviation reg. There are some drawbacks to it, as the edges are not as tough as they really ought to be for maximum strength to be held securely in place on some regs.

I too would like to know of a better material that us amateurs can work with! I know that Jerry Moseman used some two part silicone gels, but don't know what they were. I'll try to find out.
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Chris
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Re: Question on reproduction silicone diaphragms

Tue Aug 07, 2018 3:28 pm

Thanks for the info. Now another way to astonish the local "trained" divers that all think I'm gona die.
Formerly tripplec. Decided to use my real name since you guys aren't a bunch of flaky internet trolls.

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antique diver
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Re: Question on reproduction silicone diaphragms

Tue Aug 07, 2018 7:03 pm

tripplec wrote:
Tue Aug 07, 2018 3:28 pm
Thanks for the info. Now another way to astonish the local "trained" divers that all think I'm gona die.
Yeah, nothing will shock them better than a homemade diaphragm made from pantyhose and windshield sealant. :shock:

That's a good enough reason to make one even if you now have a perfectly good factory original! You don't even have to use it. Just make one to show them, proving what a dangerous and crazy rebellious diver you are! :twisted:
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Re: Question on reproduction silicone diaphragms

Wed Aug 08, 2018 1:02 am

UPDATE: In my quest to learn what kind of silicone compound is used in regulator 2nd stage diaphragms I've been doing some research on commercial outfits that make regulator and industrial diaphragms and gaskets. The two materials I keep seeing are silicone (VMQ) and fluorosilicone (FVMQ) but I'm still not sure is that is what is actually used. If it is, I haven't yet seen a supplier that sells the product. Any and all input is appreciated.  Thanks. Mark
"The diver who collects specimens of underwater life has fun and becomes a keen underwater observer. .. seek slow-moving or attached organisms such as corals, starfish, or shelled creatures." (Golden Guide to Scuba Diving, 1968) :D

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Chris
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Re: Question on reproduction silicone diaphragms

Wed Aug 08, 2018 1:09 am

We just need to come up with a smelting process and start gathering up all the old rock hard healthways diaphrams to re melt.
Formerly tripplec. Decided to use my real name since you guys aren't a bunch of flaky internet trolls.

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Re: Question on reproduction silicone diaphragms

Sat Aug 11, 2018 3:12 pm

tripplec wrote:
Wed Aug 08, 2018 1:09 am
We just need to come up with a smelting process and start gathering up all the old rock hard healthways diaphrams to re melt.
If only that would work. :D

I have been running into a brick wall trying to find out what type/compound of silicone is used to cast modern diaphragms. I made a simple email inquiry to one of the larger manufacturers and within a day got a letter (emailed, faxed and snail-mailed) to me from their bank of lawyers screaming TRADE SECRET - TRADE SECRET- TRADE SECRET ! ! ! DON'T ASK AGAIN! ! ! !

Of course now I'm even more determined to unmask this great secret (through means of public records access of course) and divulge it to the world. Any and all assistance appreciated.
"The diver who collects specimens of underwater life has fun and becomes a keen underwater observer. .. seek slow-moving or attached organisms such as corals, starfish, or shelled creatures." (Golden Guide to Scuba Diving, 1968) :D

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Re: Question on reproduction silicone diaphragms

Mon Sep 10, 2018 9:04 pm

Hi Mark,

Why don't you ask Jeff Heaton up in BC? He makes custom hoses and DivAir diaphragms.

[email protected]

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Re: Question on reproduction silicone diaphragms

Mon Sep 10, 2018 9:35 pm

Vancetp wrote:
Mon Sep 10, 2018 9:04 pm
Hi Mark,

Why don't you ask Jeff Heaton up in BC? He makes custom hoses and DivAir diaphragms.

[email protected]
I have communicated with Jeff. Seems to be a great guy, very helpful. He is working on the same exhaust diaphragm issue I am so we are trying different things and see what works best. I also had a nice long phone conversation with another VDH member today who works with military grade tactical gear and had some great ideas on the kind of material to use. Stay tuned. I will post developments as they occur. Mark
"The diver who collects specimens of underwater life has fun and becomes a keen underwater observer. .. seek slow-moving or attached organisms such as corals, starfish, or shelled creatures." (Golden Guide to Scuba Diving, 1968) :D

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Re: Question on reproduction silicone diaphragms

Wed Oct 03, 2018 12:10 am

This is my first attempt to duplicate a 1st Gen. Healthways SCUBA Exhaust Diaphragm.

I first used sulfer-less plasticine clay to insert my existing diaphragm into.

Image

I then poured the first half of the silicone mold and let it set overnight.

Image

That gave me side one.

Image

After pouring the second side and waiting another day I now had my mold.

Image

I then used a different silicon compound and cast the replica.

Image

Needs a little trimming but not bad for a first try. Original next to duplicate.

Image

Image

Mark
"The diver who collects specimens of underwater life has fun and becomes a keen underwater observer. .. seek slow-moving or attached organisms such as corals, starfish, or shelled creatures." (Golden Guide to Scuba Diving, 1968) :D

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luis
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Re: Question on reproduction silicone diaphragms

Wed Oct 03, 2018 5:32 am

That looks great. Nice work.
Luis

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h2operations
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Re: Question on reproduction silicone diaphragms

Wed Oct 03, 2018 7:22 am

That look good.

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antique diver
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Re: Question on reproduction silicone diaphragms

Wed Oct 03, 2018 8:42 am

I'll be looking to you for help and advice next time I need to make a diaphragm! Or better yet, I think I'd just like to pay you to make one for me :D

Good job, and sure looks nicer than any I have made :?
The older I get the better I was.

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Chris
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Re: Question on reproduction silicone diaphragms

Wed Oct 03, 2018 9:23 am

The beads are for alighnment, then you poor the silicone in and squeeze them together? Where did you get the materials, most things like sulferless clay are unheard of in Coos Bay Oregon. When you poored the second half, did you sprinkle in something like baby powder to to keep the halves from sticking?

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Formerly tripplec. Decided to use my real name since you guys aren't a bunch of flaky internet trolls.

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