tag:blogger.com,1999:blog-36913768.post116578950564659635..comments2024-03-28T23:08:14.827-07:00Comments on Unreasonable Rocket: Tank pressure test success...Paul Breedhttp://www.blogger.com/profile/11024641086551653462noreply@blogger.comBlogger6125tag:blogger.com,1999:blog-36913768.post-1166816207708601882006-12-22T11:36:00.000-08:002006-12-22T11:36:00.000-08:00Paul,PET and PETG are not the same material, the G...Paul,<BR/>PET and PETG are not the same material, the Glycol ( G ) modifys the properties. Also FYI soda bottles are multi-layer with different layers having different properties. Most bottles are blow molded from "parisons" ( test tube shaped objects with the screw threads on top )which is why they shrink when heated.<BR/>Have you tried polycarbonate tube? PC is not brittle, it actually has a very high impact resistance.<BR/>As far as your end caps, have you considered vacuum forming them?<BR/><BR/>HTH<BR/>GaryAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-36913768.post-1166113896225994362006-12-14T08:31:00.000-08:002006-12-14T08:31:00.000-08:00Is the tank still flexible...Yesterday I would hav...Is the tank still flexible...<BR/>Yesterday I would have said yes, today I don't think so I thought the florescent tube cover was PET, I've since learned its polycarbonate. If its polycarbonate it will be brittle and shatter. so Now I have to find a source for PET tubes and try again...Paul Breedhttps://www.blogger.com/profile/11024641086551653462noreply@blogger.comtag:blogger.com,1999:blog-36913768.post-1165982420178088112006-12-12T20:00:00.000-08:002006-12-12T20:00:00.000-08:00Is the tank still flexible at cryogenic temperatur...Is the tank still flexible at cryogenic temperatures?<BR/><BR/> jakAnonymousnoreply@blogger.comtag:blogger.com,1999:blog-36913768.post-1165904408848960592006-12-11T22:20:00.000-08:002006-12-11T22:20:00.000-08:00Hi. I've been following your blog with great inter...Hi. I've been following your blog with great interest. I've decided to do a Lander project myself. See my blog for details.<BR/><BR/>Your tanks are awesome ! As for your end caps being heavy you can machine them out quite a bit I'd think. The idea looks sound. Its really nice when something that looks good on paper actually works !<BR/><BR/>For a good pipe seal in Alu use a straight pipe thread with an o-ring or crush gasket face seal. These fittings are often used in hydraulics. And don't forget an anti-seize compound. Alu will gall really fast without.Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-36913768.post-1165903648367988332006-12-11T22:07:00.000-08:002006-12-11T22:07:00.000-08:00I can't find any larger tubes. I can find it in 4'...I can't find any larger tubes. I can find it in 4' x 8' sheets. If I can figure out how to make the seam work it would be perfect.Paul Breedhttps://www.blogger.com/profile/11024641086551653462noreply@blogger.comtag:blogger.com,1999:blog-36913768.post-1165899019101698462006-12-11T20:50:00.000-08:002006-12-11T20:50:00.000-08:00Very cool. Other than soda bottles and flourescen...Very cool. Other than soda bottles and flourescent light covers, are there any other common, inexpensive PET tubes in other sizes?Anonymousnoreply@blogger.com