Thoughts on holding hardwood with vacuum

[meatbal80]

I have started playing around with cutting hardwood rather than just sheet goods. I would prefer to use vacuum to hold down my parts but i cant seem to work out all of the kinks.

I assumed that when i placed a block on the vac table that it was not creating a good enough seal to hold perfectly still. I then created a puck with a grid system to accept gasketing. I now get a good seal and get good resistance when trying to pull the piece off. But the piece slides very easily, the gasket seems to make it a little spongy.

I would prefer not to have to use clamps/wedges/cam action clamps to hold the piece in place.

[knight_toolworks]

you need the right gasket too. but it sounds like you don't have enough vacuum. solid wood is harder as it may not be flat enough it also may let air in through pores. You would want a high vac pump and good gasketing. myself clamps or nailing it is fast and easy.

[meatbal80]

where would i get the right kind of gasket?

[ed_lang]

I hold hardwood without any problems at all.

Allstar gasket is what I use with dedicated fixtures for each part.

One Fein Trubo III (like ShopBot sells) is what I use to hold my parts.

My setup is as follows-

Same type of plenum as you would construct for a Trupan spoilboard system. I have 0.25" location holes and pins to locate fixtures onto the machine. I use 0.5" plywood for the fixtures and AllStar gasket. My fixtures can be removed and replaced with different ones or even Trupan for that sheet job.

Hope this helps.

[bob_s]

try www.allstaradhesives.com they are very knowledgeable - I would suggest that you call them before you order.
I haven't gotten mine build yet, but I am planning to use an air compressor/venturi system as well as a physical clamp. I will use screws or cams to hold the piece for all of the sculpting cuts, then vacuum for the short time it is cut out to avoid using tabs.
I currently do a lot of long cut times, hours, on sculpted parts. I don't see any advantage in using vacuum for hours, when a tiny slip will ruin a part. I have been using tabs effectively - they are quiet, don't slip, and if you put your screws in a file that uses a bit to mark the surface can be placed close to your cutting paths. I want to try this hybrid concept because the tabs can be a pain to plane and sand off on some parts.
I am cutting some cabinet parts now, and there is no question that a conventional vacuum system would be a great help if i did a lot of this.