Subject: Dry Micro question.
From: ACRE NL
Date: 2/26/2003, 8:34 PM


How do I get air bubbles out of a 50/50 mix of
micro ballons and West Systems epoxy?

That depends how much of the air you wish to remove. If you
mean serious evacuation we used to do
silicone soft tooling of parts in college. This requird that
after stirring the two part silicone
for x minutes we had to put it in a bell jar and pump it down
with a rotary vane vac pump. You
need a large jar and to be able to put the mix in a tub large
enough that it is only 1/4 full.
When the evacuation starts the mix appears to "boil" as the air
comes out and it expands quite a
bit then collapses into a very dense mix.

If you only need a small reduction, find one of the deluxe home
vacuum bag sealers, they are $250
for the one with a decent pump or tear the thing apart to plumb
in the intake line off your shop
compressor. These bag sealers let you seal the bag while still
pulling a vacuum. This is a huge
advantage for applying micro because you can snip off the
corner and use it like a pastry bag.

..Chrissi

I bought a diaphram vacuum pump off of E-bay for $12.  It draws 20 " Hg
vacuum.  There were lots of vacuum pumps to bid on at super low prices.

 
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