- On our way to vacation in Texas, my wife Jill and I were privileged to stop over at Bill and Francie Tucker's home for a brief visit. As you might recall we did a similar trip last year when Bill and I actually went diving with his Bendix Oxygen Diluter conversions. This year the timing of the drive down didn't allow time for diving but we still had a great visit.
- Our first day of driving had us arriving a full day early at Tucker's house. When I sheepishly texted to see if that would still work for them, I got a warm and friendly call from Francie saying they were looking forward to seeing us. The second day traffic held us up so that we didn't arrive until late in the afternoon. But when we got there, and the Tuckers made us feel so comfortable and welcome. Of course Bill and I talked diving while Jill and Francie talked girl talk. We went out to dinner at a Japanese Habachi and before you knew it the evening got late and it was time for bed.
- The next morning, after a Francie made us a nice breakfast, we went out to the shop to tear down Bill's latest Bendix O2 diluter project. The photo above shows us carefully (trying) to remove the original 2nd stage diaphragm. This part looks and operates very much like the 2nd stage diaphragm of a double hose scuba regulator.
- In the photo above, you can see how the lever and the diaphragm are actually attached to each other. When the diaphragm is compressed, the lever depresses a little plunger to let O2 (or air) flow into the breathing hose.
- Next, we flipped the unit over to examine the other side... Which is the 1st stage.
- As Bill explains it, this 1st stage is one of the most difficult (and dangerous) parts of the original Popular Mechanics inspired conversions. In the top right of the photo, you can see the 1st stage before disassembly.
- In this next photo (above), you can see the 1st stage in relation to the position from which we removed it.
- And finally, above you can see a close up of the 1st stage... Which is essentially a "bellows" or accordion looking thing that's made out of copper. Apparently the original setup for this system ran off an oxygen tank with only 500 psi of working pressure. And that worked fine for WWII pilots. But when you hooked it up to a scuba tank with 2250 psi of pressure, this little copper bellows would fatigue and ultimately fail... From what Bill told me, a diver might experience a blow out of the bellows.
- So a large part of making this conversion suitable for scuba diving has been to solve the 500 psi bellows 1st stage. And Bill has worked it from several directions. In one case he put a pressure reducer between the tank and the 1st stage. In another he simply pulled the 1st stage out and hooked up a 1st stage from a single hose regulator. (At least I think that's what he did). I had a great time working at the bench with Bill and I learned a lot. Not just about the Bendix but all kinds of tricks of the trade, modifications of tools, compressor configuration, etc. After our "Shop Time", we retired to Bill's den and visited some more until Jill came in and I realized it was almost noon and we were supposed to have hit the road by 10:00 AM! I hope I didn't overstay my welcome but I sure had a great time.
- Thank You So Much... Bill and Francie for your friendship and hospitality!
- BTW, in the photo above, Bill is wearing a T-Shirt from the U.S. Navy Submarine Research Laboratory in Florida... He was wearing it in honor of one of the the Sand Dog events he attended a few years back.
