Divair Plastic vs Metal

[SurfLung]

Divair Plastic vs Metal
- I have seen somewhere in discussions about the Divair regs that the plastic bodied ones are to be avoided. On the other hand, I saw I beautiful restored Divair from Mark Spencer that had a plastic looking body.
- The reason I'm asking is that my buddy Rich got me a Divair for about $25 and it doesn't look damaged... Just old. It has a shiney metal face or top can and the back side is plastic. It has a reserve, too. I'll post a photo later.

[ScubaLawyer]

Not plastic - fiberglass. Very strong and durable. Just don't try to take the body out of the can. You will end up with a pile of fiberglass shards and a cracked can.

[Vancetp]

Eben,

You got the deal of the century. I'd buy DivAirs all day long if I could get them for twice the price you paid.

OK! 3X.

The black fiberglass (let's call it plastic?) bodied DivAir is the most durable of all 3 models. Many Alu regs were upgraded to plastic by the service company. The bronze ones might have qualified for upgrading as well, but I don't know for sure.

You gotta love it: fiberglass is impervious to salt water!

I'm not saying the plastic ones perform any better, b/c I don't have any data to support or deny that. However, due to changes in the metal lever parts design, I wouldn't be surprised if it does. All of this is discussed elsewhere. There's a lot of info here and on VSS.

My plastic DivAirs breathe well. I love me a DivAir. I have rebuilt around 10 of them. Currently, I have 1 aluminum and 3 plastic, + a special one with a JBWeld repaired plastic body (the process posted here on VDH) and a 3D printed cover. It's my favorite.

Listen to Mark: Do not attempt to remove the valve from the plastic body! You will FUBAR that reg.

Post some pictures, pls...!

Phil

[Vancetp]

So, in regard to your original question, the metal bodied DivAirs suffered so badly from salt water corrosion, the company decided to offer an upgrade to plastic for a "minimal fee".

I don't know how much the conversion cost, but many owners took advantage. So, they'd take in a metal Divair and swap all the parts from it to a new body. The original cover, with serial #, would be installed on the converted reg. By doing this, they created a nightmare for all of us interested in the history of it all. This is discussed in threads here on VDH and on VSS.

It's a mess.

[SurfLung]

- Thanks for the good advice... So I got the best version! Well here's how the $25 deal went down:

- Rich 50,000 Questions was out of town and visited a dive shop. The owner had a box of tank bands and harnesses and Rich called me up to see if I wanted what's in the box. The owner said "shoot me a price". So I said, "Would $25 be too low?" We're on speakerphone. And I hear them on the other end, "Hey there's also a double hose regulator in the box. Is it a Dial-a-breath? No it says Divair... I never heard of that one."
- Well, I have heard of a Divair. SwimJim has told me about the Divair. So I said, "I've heard of that one. Okay how about $50 for the Divair and the box of bands?" And that's the deal we agreed on... Sight unseen.

- I'm sorry I still haven't taken a picture of it. But last Saturday I took the metal top off and found the diaphragm is shot... Just the metal disk was left. And the big circular clamp that holds it was still there. Nothing broken and the lever moves freely. I put it on the scuba tank , turned on the air and the lever releases air properly when depressed. There was a little hissing air leakage. I tried squirting some food grade silicon lube into the air inlet at the yoke. Then connected and pressurized again and the hissing was less... Almost not at all.

- Then yesterday, SeaHunt Jerry sold me a new diaphragm that was made by Jerry Moseman. So hopefully, little clean up and re-assembly and I may have this thing working without a total re-build.

[Vancetp]

There isn't much to it. A couple of o'rings and the HP seat are pretty much all that need any service, other than the diaphragm. There's no exhaust valve in it. If you are interested, I have the large and small screens that were used instead of a sintered filter. You can use a sintered filter in it no problem.

The nylon seat can be resurfaced (very carefully), and there's a couple of mods you can do, including one that mods a Healthways soft seat. It is smaller in diameter than the DivAir seat, so a sleeve has to be put over it, or a sleeve needs to be fitted inside the valve body.

There's a discussion about these seats here: https://vintagedoublehose.com/forum/vie ... r&start=15

[SurfLung]

- Okay, so I'm skipping past the photos and cleanup and going straight to the video. My buddy SeaHunt Jerry supplied me with a brand new diaphragm that was made for him by the late Jerry Moseman. Very fragile and sensitive, but after clean up it installed just fine. I haven't closed up the patient yet and I've always been curious as to how those funny looking DIVAIR diaphragms work. Also, how does the exhaust work? The video shows the diaphragm pretty well but the exhaust slot is hard to make out. It's a slot in the main body that empties outside the rim of the diaphragm.

- I mentioned earlier that I could hear a leak. Well it seems to have gone away with some use. So at this moment, I think I can close this patient up, put the new hoses on and she'll be ready to dive... Yes that seems like an awfully quick restoration!

[Vancetp]

Here's the diaphragm made by Jeff H. It is an exact copy of the late OEM part but in silicone. It appears to be less floppy than Jerry's due to the shape and big disks. I don't know if the uneven pull of the Moseman diaphragm has negative effects.

DSCF2013 by Vancetp, on Flickr

Supposedly, the design of the exhaust port keeps the hose from flooding, mostly. I know that it doesn't completely when the diver is in some positions, esp head down.

IMG_5071 by Vancetp, on Flickr

The above picture shows the exhaust opening.

One of my Alu DivAirs with a metal mouthpiece (no non-returns) has a mushroom/ww inserted into the end of the intake hose at the horn end. I suppose that the early divers were just used to clearing hoses!

IMG_1497 by Vancetp, on Flickr

[SurfLung]

My Photos...
- Sorry so late on these. They're redundant since Vance has similar views. But I took them so here they are. The top one shows my DIVAIR before cleaning it up as well as the underside of the Moseman diaphragm.

- This one shows the exhaust slot quite a bit more clearly than the video.

- Regarding the diaphragm made by Jerry Moseman, I think SwimJim's DIVAIR is also equipped with a Moseman unit. Jerry Moseman was before my time with this group and then he passed away. So I never knew him. BUt I understand he was quite a pioneer in the Vintage Diving community. SeaHunt Jerry was telling me that some of Moseman's early diaphragms were made from a rubber dishwashing glove. Considering the full diameter metal disk my original diaphragm was incorporated into, I can now see how he might have done that.
- Considering how delicate this diaphragm is, I'm thinking it might be a very easy breather.

Interesting Point - The DIVAIR is a single stage, upstream regulator. I always thought that Gagnan developed the single stage AFTER 2-stage regs were developed and I thought the Gagnon single stage was first. But these DIVAIRs are in quite a few old movies that seem older than movies with Gagnan regulators. So, who's single stage regulator was first?

[Vancetp]

Note the difference between the lever assemblies on my DivAir and Eben's. Mine was a C model (aluminum) that got upgraded to plastic by the service center. I believe that the redesigned lever on Eben's directs the airflow into the intake horn more efficiently. Also, the lever retainer on mine has no adjuster. It's the only one I've ever seen that lacks one. It isn't really an adjuster, but functions as a stop so the lever doesn't flop around.

[swimjim]

About 14 or 15 years ago I went to Haigh quarry down in Kankakee Illinois to go diving with a buddy of mine. I went into the dive shop to pay my entry fee and sign the release. There was a DivAir mounted on the wall. I had never seen one prior to that and looked into it. That led me to buy one off ebay. I had a good aluminum body. The seat sealed when I put pressure to it. But the diaphragm was toast. I used a swim cap to make a diaphragm and it not only worked, it worked well. I was really surprised on how well this reg breathed. I did a right up here on VDH about the experience. That's how I got together with Jerry Mossman. We spoke to each other on the phone. He told me how "back in the day" he dove DivAir's a lot. He even dove them under the ice. He made several for me to test. They all worked well. The one that Eben has was a third and last generation diaphragm. Unfortunately, not long after Jerry produced that batch he got cancer and was taken from us. He was a stand up guy who was passionate about DivAir regs and double hose regs in general. He is missed by those when got to know him.
I have dove my DivAir several times every year and really enjoy the reg. So far the diaphragm that Jerry made has held up just fine. The DivAir concept is more like a bellows that what you would thing of as a normal diaphragm. The whole reg really is some what unique. That's why I enjoy the reg so much. It doesn't hurt that it's a nice breather too. Really smooth! I'll close this out by posting a video I made during the test phase of Jerrys work.

Swimjim


https://vimeo.com/manage/8556402/general

[SurfLung]

- Forgive me for taking the liberty of re-posting your video for easier click and watch...
- Thank you for the background info on Jerry Moseman.

[SurfLung]

Finished Project...
- Like Vance said, there wasn't much to it. This DIVAIR mainly just needed a cleanup, a new diaphragm, and hose loop. I chose blue hoses to match later models and I used a gray mouthpiece to simulate the Hope-Page mouthpieces of later models. I've put it on a Scuba tank and breathed through it and it seems to breathe very easy and smooth. Here are some photos I took of the finished project.

[Vancetp]

Thanks for posting the pictures. I'm glad to see these being refurbished and used!

The Hope-Page mouthpiece had much to do with the good breathing characteristics of the DivAir. Jim's appears to be set up with a USD hoseloop, which may perform even better.

[swimjim]

I have tried both the Hope-Page and the USD curved mouth piece. The curved mouth piece while not historically accurate gives the best performance. I can't wait to do a DivAir dive with you Eben. Your really going to like that reg!