Not a Sea-Hunter but love the gear

[duckbill]

When your tech services your double hose, ask him to let you watch. Although you may not want to service your gear completely, it helps to know how the thing works. Plus you'll need to take it apart just to change out the duckbill. The regs mentioned are very simple in design, and easy to work on. But do yourself a favor & get the reproduction band clamp from VDH. The clips around the can are a real PITA.

Good idea to watch, like BSea says, but you only have to remove a hose to change the duckbill.
I personally don't mind the clips. I have my own technique which works for me, and the new, reproduction band clamps don't always tighten sufficiently unless you put unsightly crimps around the edges. A friend of mine ended up making a diaphragm gasket to add thickness like there was on the Aqualung regulators. The later round label USD regulators were made with them and they worked fine. A band clamp may work for you too, and is worth a try. They do make opening the cans easier. If you get one, I suggest you replace the stainless screw and nut with brass or even zinc plated steel (which are cheap enough to replace at the first signs of corrosion. The stainless on stainless can gall and seize something terrible after a few assemblies/disassemblies and you may end up having to twist off or cut the screw to get it apart.

 

[captain]

Try a little silicone grease on the screw. I have never had a galling problem. If you want to be assured of having a problem use zinc plated steel.

 

[pescador775]

Stainless will seize in aluminum. Dow Corning silicone is the preventative. Personally, I've never had a problem with band clamps or screws but I use the original USD clamps and have no experience with repo's. Plated screws are junk and I would not use them. The new, repo, silicone rubber diaphragm seals perfectly without a gasket, at least in my reg. Come to think of it, I've disassembled several round label regs which were brand new and never seen a gasket, yet. As it is, my regs would not close if a gasket were used. The thickness would not allow the clamp to compress enough to get a bite with the clamp screw. I might be able to close the box with clips but why bother?

 

[BSea]

Good idea to watch, like BSea says, but you only have to remove a hose to change the duckbill.
I personally don't mind the clips. I have my own technique which works for me,

Duckbill's right, you don't have to open the reg to change the duckbill. I've only changed them when I service my reg, so that why I mentioned the duckbill for self service.

I'm getting better at the clips, but I still don't like them. My limited experience with bank clamps has been good. I have a snark III and a RAM that have band clamps, and I wouldn't want to do it any other way. Having said that, I have a 58 DA that still has clips, but I don't dive it often. When my yellow hoses arrive, I'll be using it more.

Stainless will seize in aluminum. Dow Corning silicone is the preventative.

I'll have to do this from now on.

 

[Nemrod]

I have never seen gaskets on a USD regulator under the diaphram--maybe I missed something. There are differences in cans as to port positioning and even the rim height that could cause some problems with band clamps. Thus the cutout needed on some regulators for the ports. The NOS clamps seem to work best but I have good success with the reproductions as well wih a little work they seem just fine. I have several NOS type USD diaprhams and note that there are differences in bead thickness on them. The silicone diaphrams seem to be to the thicker range but within spec. I think that you may find that band clamps that were loose on some older diaphrams may now fit perfect. N

 

[duckbill]

I've disassembled several round label regs which were brand new and never seen a gasket, yet.

The round label regulators were designed for band clamps.

The gaskets were used in the original Aqua-Lung, which used clips. I guess the diaphragms were made thinner and/or of a different material.

The only reason that zinc plating isn't all that great is because of the thickness of the zinc. Steel SCUBA cylinders, tank bands and their hardware have all been made with zinc (galvanized) coatings and are very corrosion resistant. But, I haven't found any hot-dipped screws in the size needed for a band clamp and brass may be too soft.

 

[duckbill]

I don't have a silicone diaphragm yet, but I love the idea. Silicone should last a lifetime. Pescador and Nemrod have pointed out that the new silicone diaphragms are thicker and seal very well with band clamps. So,...


novicediver,
Go get yourseld a USD double hose regulator and if it has clips (and function takes precedence over historical appearance for you) then get a silicone diaphragm or two and a band clamp and you're good to go (once it is serviced, of course). If it already has a band clamp or you want to stay with clips, then get a silicone diaphragm anyway! But, don't throw the original parts away. Just remember you need some education and pool time to become familiar with the effects of regulator position and to practice hose clearing. You can figure out the "nuts and bolts" of the thing for yourself. I hope you join our ranks soon.

 

[Nemrod]

Get the silicone diaphrams, I get no kick backs or gain from recommending them, I recommend them highly. They are much more flexible and in most cases should make a noticeable difference in breathing effort and cracking effort. Nothing will turn a sow's ear into a silk purse so if the regulator has other issues those must be delt with but an otherwise healthy regulator should see a noticeable increase in performance. Plus, the silicone diaphrams and silicone hoses and other parts are chlorine resistent so you can get in more quality pool time--lol. Of course the duckbill (cheap and easy to replace) and those of you who still have the neoprene cage valves (silicone valves are rare and come and go on the market) will still have those issues with chlorine. N

 

[captain]

I have never seen a diaphragm gasket in a USD regulator nor one listed or mentioned in a manual or parts break down.

 

[duckbill]

I have never seen a diaphragm gasket in a USD regulator nor one listed or mentioned in a manual or parts break down.

You will find it in the SIO (Scripps Institution of Oceanography) reference 53-28, "Overhauling The Aqualung", text (pg 4, "disassembling procedure", step 2; and pg 8, "assembling procedure", step 16), and Figure 2 (on pg 3). This is for the "Broxton" Aqua-Lung, ca.1953.

If you don't have a copy, you can see it in pdf at:
http://www.vintagedoublehose.com/downloads/Scripps_Overhaul.pdf