Is JB Weld High-Vacuum Safe?

[Ryan Atkinson]

I believe I've heard of JB weld and similar epoxies being used in high-vacuum environments for lower quality fusors and cyclotrons. Personally, I see a major offgassing problem with this. Does anyone know if it could hold up to the task, just for use in a bare-bones fusor or for other high-vacuum equipment? Thanks!

-Ryan

[John Futter]

Ryan
Read this forum
there is plenty of info

[RobertTubbs]

Yes.

[Jeroen Vriesman]

Nasa has an outgassing database:

http://outgassing.nasa.gov/index.cgi
Go to search and just type "JB weld" in the box.

What is also important is the high temperature it can handle, it means you can do some bake-out.
Curing temperature, material thickness and surface area exposed to the vacuum is also important.

I have used "Hysol 9497", cured for one hour at 100 deg.C and then used it in vacuum (bake-out at 100 deg. C for 2 hours), no problem reaching < 1E-5 mbar.

[Ryan Atkinson]

Nasa has an outgassing database:

http://outgassing.nasa.gov/index.cgi
Go to search and just type "JB weld" in the box.

What is also important is the high temperature it can handle, it means you can do some bake-out.
Curing temperature, material thickness and surface area exposed to the vacuum is also important.

I have used "Hysol 9497", cured for one hour at 100 deg.C and then used it in vacuum (bake-out at 100 deg. C for 2 hours), no problem reaching < 1E-5 mbar.

Thanks, this was very helpful.

-Ryan