DivAir #10

[vance]

I just picked up a lot of 3 DH Scuba regulators, even though I said I was trying to pare down the collection, not add to it. None of the regs are in very good shape, but WTH. I can't resist fixing stuff that needs it, and the price we arrived at was fair. 

The lot includes a DivAir Model F, which was the reason for the buy. This thread concerns the DivAir, and other two might be featured in their own. 

My last DivAir, the 3D, has a new owner (Fred), and I realized that left me DivAirless. That's a state I do not wish to be in! Add the fact I have two new DivAir diaphragms going begging and it makes sense to me.

This DivAir has an interesting lock-out on the reserve mechanism that I've never seen before. You can see the stump of the lever in the groove. I'm not sure why anyone would do that. 

 

The wedge shaped lock part looks very familiar. It might be a modded reserve part taken from inside the reg.


 

[SeaRat]

Interesting. I've never dived a DivAir. What do they breathe like?

Concerning the lever lock, it actually looks like it was from the factory.

John

[nikeajax]

Ohhhh--VERY FUN! Yeah, that looks like a kludge to me too: perhaps the owner didn't want to deal with having even think about the reserve. Looking forward to hearing more about it

And yes, I also agree about it looking familiar: it feels like some kind of insert-key, like maybe to keep something from spinning, like a door knob...

JB

[nikeajax]

John, they breathe exceptionally well, you wouldn't think something that old could deliver as much air as it does

JB

[vance]

I am waiting to see what the internal parts look like. As noted before, the "F" models could be "B" or "C" aluminum bodied regs converted to fiberglass by the factory. There are some lever differences in later models that make the reg perform better.

[vance]

I think I would position the reserve to be "on" rather than off. Why limit the tank pressure if you have no reserve?

On second thought, the reserve might be disabled on this one (since that locking wedge might be the reserve actuator), so it might not make any difference which position the lever is locked in. We'll see!

[vance]

Here are the promised photos. These are after disassembly and cleaning. The reg doesn't look much different, except for the diaphragm.

Note the Scuba HP seat. I replaced it with a larger diameter DivAir seat. I wonder if the Scuba seat worked ok in use? I didn't pressurize the reg before I disassembled it, so I don't know if it held air. That's an interesting experiment for another time! 







This is the HP filter. Arpin didn't use a sintered filter, just these 3 screens.



And the completed, working regulator.

[vance]

This is a late model DivAir. Note the 2 adjuster screws on the lever system. There isn't anything mysterious about adjusting them. The center one adjusts the lever height. The body design allows the lever to flop upward with the diaphragm off, so they put in the second adjuster simply to eliminate the slop (and possibly some noise?).

Also, the late model levers have short fingers that contact the diaphragm plate. This makes the lever act as an air director when the lever lowers down over the air channel to the intake horn.

As mentioned in other DivAir threads, the metal body DivAirs were often upgraded to the plastic body by the manufacturer. They would swap all the parts from the old body to the new, so many fiberglass DivAirs have early internal parts installed, and have covers with model and serial #s that don't match up.

[vance]

The DivAir didn't have any kind of exhaust non-return built into the body. The exhaust design cast into the body (check out photo # 2 two posts above) was meant to get around the need for one (and probably Cousteau's patent). However, in practice divers found that in certain positions the exhaust hose could take on water or flood. The fix was to insert a wagon wheel and mushroom valve that fit into the corrugations of the hose near the exhaust horn.

[vance]

I happened upon the fine screens on Amazon or eBay a while back. They are a perfect match. I had to buy 100, and still have some. Anyone need any?

[james1979]

Sept 13, 2023 15:15:09 GMT -8 vance said:

I happened upon the fine screens on Amazon or eBay a while back. They are a perfect match. I had to buy 100, and still have some. Anyone need any?

I wouldn't mind a few next time something is headed my way.

[vance]

You got it! Remind me when the time comes.

[vance]

Because I am emotionally attached to it, I decided to try to back out of my promise to give it to Fred, and keep the 3D Divair.

So, I offered this one to him in its place. He graciously accepted (because he's a nice guy, and this one is not a modded and repaired wreck).

Wise decision, Fred! But appreciated.

So the DivAir is off to Brussels, and will be in Fred's capable hands for some dive testing. I am looking forward to his experience(s) with it!

[vance]

I sent it off today with a VTP-made Snark III LP poppet. I'm looking forward to Fred's review of the DivAir.

Although it gets touted as an extraordinary breather, it really isn't as great as all that. It's amazing for a 1950s regulator, but it's nowhere as good as a later USD single stage regulator.

My rating of it is that it's better than a Scuba Deluxe.

[vance]

Sept 12, 2023 14:31:22 GMT -8 vance said:

The DivAir didn't have any kind of exhaust non-return built into the body. The exhaust design cast into the body (check out photo # 2 two posts above) was meant to get around the need for one (and probably Cousteau's patent). However, in practice divers found that in certain positions the exhaust hose could take on water or flood. The fix was to insert a wagon wheel and mushroom valve that fit into the corrugations of the hose near the exhaust horn.



I believe I sent Graeme or Neil (Red Rover) this part for an aluminum DivAir.