Gassing off/ Degassing???

[doohboy24]

hi again everyone. well pressure tank is assembled and currently under test pressuring. was sitting here reading some things about castings so i can try tonight. i have bought just a quart from micheals casting craft and the hardener. i have read alot about gassing off or degassing. what is that and when do i do it? is it needed to be done??

 

[toolcrazy]

I didn't degas the first cast I did under pressure, and didn't get any bubbles.

Degassing is a method of removing the bubbles from the mixed resin. Some use a jewelry sonic cleaner to vibrate the bubbles out. I also saw a home made unit made from an old vibrating chair pad. I cast at about 40psi, so this may be why I didn't get any visible bubbles. Some say that it don't need to be that high, but it worked form me.

 

[Blind_Squirrel]

You can also put the resin under vacuum (if you have a vacuum setup) to try to expand and remove the air from the resin. The only time I "worry" about bubbles is when I am casting clear or translucent resin. If I am casting solid blanks (not around a tube) I put the resin under 4 bar (almost 60 PSI) of pressure. I have never noticed any voids in my blanks.

 

[stevers]

I seldom de-gas. Pressure seems to remove (compress) all of my air.