Attaching the spoilboard

[maginter]

I have a question with regards to the spoilboard and attaching it to the vacuum plenum board/surface. In my previous configuration I used a rubber seal around the perimeter of the zone. That worked OK as I only had four zones. However I didn't always end up with a flat surface. Since I have reconfigured everything, I wanted something a little more reliable and semi-permanent. I now have eight zones with t-track in between. I dont want to glue the spoilboard down to the vacuum board because if I have to change out one of the eight zones, it would really be hard to maintain consistancy. What I was thinking about was using 2 inch carpet tape to attach the spoilboard to the vacuum board.

My question..... Has anyone done this and were they successful in maintain vacuum through the zone with minimal loss. Also I just happened to think. Since I sealed my Vacuum board could I use a small bead of 100% silicon adhesive to attach the spoil board. I am only looking at attaching the eight individual spoilboards around each of their perimeters.

If this has been dicussed before I apoligize. I looked for a reference, but my search came up empty.

TIA,

Mark

[Brady Watson]

I wouldn't bother with a sealant or gasket, as it would be a waste of time on a low Hg"/High CFM setup. You only really use gasketing when you have very small parts or a high Hg" vacuum source with low CFM. Gaskets cause more problems than they cure for most applications.

Even with gasketed, or partitioned zones, you are still going to get some zone to zone cross-over of vacuum due to the nature of a bleeder board. The bleeder is porous, especially in the side-to-side areas and will still leak into other zones to some degree no matter what you do. The only way around this is to construct large vacuum 'pods' that have every edge sealed - but this is generally a waste of time if your intention is to cut different types of projects from one day to the next.

Carpet tape is OK, but will leak from one zone to another MORE than using nothing at all between zones. I prefer to just edge band, seal and adhere the bleeder to vac grid all in one shot by taping the entire perimeter (of support board/grid and bleeder) with aluminum foil HVAC tape. It has enough grab to keep the bleeder from shifting even with aggressive 'slaps' of material onto and off of the machine.

-B

[maginter]

Hey Brady -

Thanks for the reply. My intention is to have eight spoilboards cut to fit each zone. Each spoilboard will have the edges sealed to minimize the bleed. Do you still hold to your original comments with this explaination?

Thanks again....

Mark

[beacon14]

With eight small spoilboards I think you will have a problem with dust getting between and under the spoilboards, ruining your flatness.

I'm with Brady, except I've been using Gorilla tape to go around the perimeter of the table/spoilboard. Keep the vacuum running while you apply the tape. It's not perfect, but it works and can easily be removed to get to the T-tracks.