Tool for casting parts.

[boss subfixer]

If this is in the wrong place please feel free to move it.
I got a new harbor freight catalog in today for fall and they have a 2 1/2 gallon, pressure paint tank item # 93119-1BCB on sale for $40. They are usually $80. These are real good for deairing mold making rubber, for those of you that don't know this, this is key to making smooth bubble free castings.
Take care.
Don

[mylo]

Boss,

I'm just getting into

Boss,

I'm just getting into casting my own parts and am constantly looking for information / how to.

Thanks for this.

Mylo.

[boss subfixer]

Mylo your welcome. Not really

Mylo your welcome. Not really my idea I just saw this at a real good price.

[hampboats]

Pressure pots

How much pressure is required to de-air a mold? Without being able to see the mold inside, is there a way of determining if you have enough pressure? I have been thinking about getting one of these.

[m. munger]

I believe the term "De-airing"

I believe the term "De-airing" refers to putting the subject material in a 'hard' vacuum (~29 inches of mercury) using a vacuum pump, there-by extracting any and all air from it. Silicone casting rubbers are "de-aired" to eliminate any air-entrapment within a rubber mold/tool. You can also "de-air" a casting material while in a mold, to get you closer to a bubble-free pour.

Putting your casting material under pressure (~30 psi +/-) prior to it changing state (curing), will crush most if not all trapped bubbles, depending on your mold sprue/vent geometry.

The tank mentioned is a pretty good bargain, relatively fast closing/sealing (time can be 'of the essence' with some casting materials!) with its four wing-nut clamps, plenty of plumbing connections. It should work well within our nominal pressure ranges.

Mr Merriman long ago shared his techniques with me, and now shares his methods and strategy with us all at:

http://vabiz.com/d&e/articles.html . Check out some of the Cabal

Reports Thanks Master!!!

Matt

[seaphoto]

That tank works very well

That tank works very well - a buddy of mine modified mine with a manifold so that the air pressure did not disturb the mold, blowing resin everywhere - he did this by adding a length of tubing in a "s" shape, and drilling a lot of small holes so that the pressure is dispersed around the permimeter of the pot, instead of shooting straight down.


Kurt

[boss subfixer]

Thats a good idea. One

Thats a good idea. One less boobie trap to step in.

[Guest]

I use a modified pressure

I use a modified pressure cooker, which is a cheap way to get a good pressure pot. Very quick sealing, as it clamps together using a bayonet lock system.

Andy