Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: version B 2.10.1 6/24/83; site ttidcc.UUCP Path: utzoo!linus!philabs!ttidca!ttidcc!sorgatz From: sorgatz@ttidcc.UUCP ( Avatar) Newsgroups: net.rec.scuba Subject: steel vs. aluminum tanks Message-ID: <656@ttidcc.UUCP> Date: Thu, 8-Aug-85 22:17:50 EDT Article-I.D.: ttidcc.656 Posted: Thu Aug 8 22:17:50 1985 Date-Received: Sun, 11-Aug-85 07:02:52 EDT Organization: TTI, Santa Monica, CA. Lines: 41 < munch! gobble! chomp! chew! Why don't "THEY" fix this bug? > Here I sit, typing away at what might be the last message to ever get posted to net.rec.scuba...shudder! Would "THEY" really remove such a nice newsgroup? Annnyywaay..I recently did a 'side-by-side' comparison of the buoyancy factor of each type of tank, in a pool. The tanks were: a) aluminum LUXFER, 80 cu ft. b) steel PRESTEEL, 74.2 cu ft. The two tanks have approximatly the same weight when full, in submersion the steel tank provides -4lbs of buoyancy whereas the aluminum one is just a bit over -3. The real surprise, however, is that when the tanks are 1/2 full the aluminum 80 is +1lb. The steel tank was NEUTRAL when empty, and at the 1/2 point still has a +2. The aluminum 80 when empty was exerting better than +2! FACTORS: 1) I used a cheap fishing-scale and the same monofiliment sling. (the accuracy of which is +or- 8%) this may make these figures a bit low, if the out-of-water tests were any indicator. 2) Things in the pool, of course, have less buoyancy than they would in salt water. This could be corrected. OBSERVATIONS: When I use the aluminum 80, I need 28lbs of weightbelt ballast. With the steel 74.2 this is only 20-24lbs! The bottom time(for me at least) is not greatly different. CONCLUSION: I'm gonna buy a steel 96 and see if the buoyancy/bottom times are more in my favor. (-: (it sure would be nice if someone would come out with a TITANIUM cylinder, I think about 6000 psi in a profile like a steel '60 would be great!) -Avatar-> Erik K. Sorgatz Transaction Technology Inc. (Citicorp's R/AD West) ... . ... . ... 3100 ocean Park Blvd. (zone V1) . | |..|..| | . Santa Monica, Ca. 90405 |.|....|....|.| USENET path: {garfield,lasspvax,linus,cmcl2,seismo} |.|....|....|.| !philabs!ttidca!sorgatz | | ...|... | | ("..My poor Krel! Even they must have evolved up from the ..| | .|. | |.. mindless primative..after a million years of shining sanity, they could hardly have know what was destroying them!" -Dr. Morbius F.P.)