vacuuming investment

I read about using a vacuum arrangement to remove the bubbles from
investment, then pouring it into the flask around the model and
vacuuming it again. Seems redundant, why not mix it, pour it in
and just vacuum it once? Or have I mis-read?

-- Carl


If you try to 'reply' to me without fixing the dot, your reply
will go into a 'special' mailbox reserved for spam. See below.


--
Carl West http://carl.west.home.comcast.net

change the 'DOT' to '.' to email me

"Clutter"? This is an object-rich environment.

Carl West wrote:

I read about using a vacuum arrangement to remove the bubbles from
investment, then pouring it into the flask around the model and
vacuuming it again. Seems redundant, why not mix it, pour it in
and just vacuum it once? Or have I mis-read?

During first vaccuming, the investment is rising to 120 - 130 %volume.
If you would do it in the flask with the mold, it would run out of flask.
The second vacuuming is neccesary to remove air bubbles in undercut
regions of the form. If You have simple forms, the second vacuuming is
not neccesary.

Best wishes,
Heinrich Butschal


--
www.juwelen.online-boerse.org
www.meister-atelier.de
www.schmuckfabrik.de
www.medico.butschal.de

On Tue, 11 May 2004 00:37:33 GMT, Carl West
wrote:


I read about using a vacuum arrangement to remove the bubbles from
investment, then pouring it into the flask around the model and
vacuuming it again. Seems redundant, why not mix it, pour it in
and just vacuum it once? Or have I mis-read?

-- Carl
I've always done it this way. I don't know exactly why, but I get very
few bubbles with double vacuuming. And I've only 'missed' two to three
castings out of the last couple of hundred.

Leo