# How can I make this?



## sethndaddy (Dec 4, 2004)

something to get the bubbles out of silicone molds....I saw once awhile back someone made a "pressure chamber" out of a gallon paint can.
I take it a compressor would be needed, I work at Home Depot, could I get one small enough there, or search the hobby world.
thanks guys


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## vaBcHRog (Feb 19, 2003)

Be very very carefull if you try to make a homemade pressure chamber. Pressure chambers are nothing to fool with as they can explode and hurt you. I would recommend you get a vacuum pump and degass the silicone prior to pouring your mold.

Where are you getting bubbles in your silicone mold?

Two things that can help with air bubbles. 

One is after mixing your silicone pour it vety slowly from 24 inches above your mold you will get a very thin ribbon of silicone as it pours.

Two, you can mix a very small amount of silicone and brush it on the car you want to mold. Two coats will prevent an bubble for normal castings.

However the above will not prevent air bubbles inside the silicone mold which you can not see. However these will only be a problem if you are pressure casting your resin.

Roger Corrie


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## sethndaddy (Dec 4, 2004)

vacuum pump and degass the silicone prior to pouring your mold.
WHAT DO I USE FOR THIS ?? I USE SMOOTH ON ALSO AND NEVER THOUGHT OF THE BRUSH ON IDEA. I GET A SMALL BUBBLE HEAR AND THERE, BUMPER OR WINDOW, NOTHING BIG, BUT IT DRIVES ME CRAZY TO TAKE ALL THAT TIME TO HAVE A LIL IMPERFECTION LIKE THAT.


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## sethndaddy (Dec 4, 2004)

another thing, I do one part slosh molds and found the silicone tearing very easily lately. I tried a 2 part mold once and found I could barely get the 2 parts apart without ruining the mold (they were so tight) 
Roger, would you be kind enough to email me a close up pic of the 2 parts so I can see where I went wrong?


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## vaBcHRog (Feb 19, 2003)

sethndaddy said:


> vacuum pump and degass the silicone prior to pouring your mold.
> WHAT DO I USE FOR THIS ?? I USE SMOOTH ON ALSO AND NEVER THOUGHT OF THE BRUSH ON IDEA. I GET A SMALL BUBBLE HEAR AND THERE, BUMPER OR WINDOW, NOTHING BIG, BUT IT DRIVES ME CRAZY TO TAKE ALL THAT TIME TO HAVE A LIL IMPERFECTION LIKE THAT.


 I have an automotive airconditioning vacuum pump. I use Food Saver 1 QT and 2 QT containers to mix and degass the silicone.

Roger Corrie


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## vaBcHRog (Feb 19, 2003)

sethndaddy said:


> another thing, I do one part slosh molds and found the silicone tearing very easily lately. I tried a 2 part mold once and found I could barely get the 2 parts apart without ruining the mold (they were so tight)
> Roger, would you be kind enough to email me a close up pic of the 2 parts so I can see where I went wrong?


 Which Smooth-on silicone are you using? I use the Ooma 25. Your molds should not be tearing when you slosh cast. Do you heat the mold prior to adding the resin?? I heat mine for 1:30 in the microwave. You can also try dusting the mold with talcum powder or baby powder prior to pouring the resin this acts like a mold release and also relieves the surface tension which helps get rid of any tiny air bubbles. A two part mold is tight howver the mold should be flexible enough to remove it. Try adding a little baby oil to your silicone mix 5 or 6 drops this makes the molds a little more plyable.



















Hope this helps

Roger Corrie


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