Great Dane excavating co.

[modelman]

Originally Posted by bigford

wouldn't it draw the air out the 4 vent tubes?

No, Vacuum is meant to be used on an open mold or table or a flat surface. Example-if you vacuum something down on a flat table, you seal the part around the edges and vacuum the air out from under the bag and atmospheric pressure pushes the material down against the table. The same thing happens when you pull a vacuum on an open mold. BUT-if you pour wet rubber into a rubber mold the vacuum will distort the mold and just force all the wet rubber from the mold. Most people don't realize that atmospheric pressure does all the work when bagging. The vacuum pump just pulls the air from underneath the part. Hope this makes sense