vacuum chucks

Re: vacuum chucks

Jeff Willaford

I use adhesive backed craft foam from Walmart. Seems to work just fine for me for.

Re: vacuum chucks

Pete in Holland MI

There's a craft foam with PSA available at Craft stores (multiple colors too !). That's what I and others use.

I assume the wood chucks have been sealed with a couple coats of varnish? Lightly rub your hand over them while it's sucking on a sealed bowl. Feel sticky? If so, that's the air being pulled thru pores in the wood. A couple liberal coats of varnish will seal it.

Pete

Re: vacuum chucks *LINK*

Dave Paine

My high school physics teacher told me "Nature abhors a vacuum". Very true.

In my experience, it is easier to maintain positive pressure than negative, i.e. vacuum.

Any aspect of the chuck may leak, especially the wood itself. The wood needs to be sealed which may require several coats of sealant/ finish.

The chucks need a gasket to seal between the wood and the work. Some foam materials work. If the work is not flat or the wood chuck is not flat, or if both are not parallel, then some thickness in the gasket helps to conform to both surfaces.

I purchased the rubber gasket material in the link. Works well to fill imperfections in the fit between the chuck and the work.


http://www.packardwoodworks.com/Merchant2/merchant.mvc?Screen=PROD&Store_Code=packard&Product_Code=110920&Category_Code=lathes-acc-vc-holdfast

vacuum chuck gasket tape

John K Jordan

I bought everything from Joe Woodworker.

He says:

"The last part is to attach a vacuum gasket to the rim on the drum. After I (unsuccessfully) tried several types of gasket material, I found one that did exactly what I wanted."

http://www.joewoodworker.com/veneering/vacuumchucking.htm

I haven't built my chucks yet but his vacuum gasket tape does look and feel very good. And it's pretty cheap. And I've come to trust Joe.

http://www.veneersupplies.com/products/Vacuum-Chuck-Gasket-Tape-34-x-116-x-3.html

JKJ

closed cell foam is what you want

Re: vacuum chucks

John C Lucas

I've tried a lot of material including commercial rubber designed for that purpose. My favorite ie the closed cell foam sheets I get from Hobby Lobby. It seems well and is thin enough that it doesn't throw the bowl off center. It can be cut larger and wrapped around the edges a little. I glue it on with clear silicone caulking. The downside is its thin. If the bowl warps much it won't seal well. In those cases I use a square piece with a hole in the center as an extra thickness. Place it over the face of the Chuck and insert the bowl. The square corners help position it. Once you turn the vacuum on it seals perfectly.

The other easy to find material that works well is the gasket material used to attach truck toppers to the bed. It's self adhesive and comes about 2 inches wide. I just butt several strips together and then seal any gaps with clear silicone. It's a little thicker and seals most bowls but doesn't hold up as long. However you have to buy it in rolls so you always have plenty of extra

Re: vacuum chucks

Barry Irby

I went to commercial gasket shop and bought "Armaflex" (sp?) or closed cell Neoprene. Bought some that was an 1/8" thick and some that was 3/8". The 1/8" stuff worked well, but the 3/8" was too thick and deformed too much and made it nearly impossible to center the bowl or whatever.

Have also used Foamies from Walmart and they worked well.

And the advice you got about sealing the wood is correct. Coat it with varnish and let it dry. You can also use packing tape. Doesn't take much of a seeping air leak to kill the effectiveness of the vacuum.

Re: vacuum chucks

Jeff Smith

I've made a few, but after using the precision vacuum hub that JT Turning Tools sells, it is the one I go to most often. It takes common PCV pipe adapters and seals with an o-ring. You can change out the adapters easily for different sizes. I've got 2", 3", 4" and 6" adapters. Just true up the adapter face, glue on some closed cell foam and you're good to go. They seem to last forever - I've never had to change them - yet anyway. JT also makes a very good vacuum adapter for most lathes.

Re: vacuum chucks

Doug Turnerdougturner1 cox.net

I use closed cell foam packing material that substitutes for bubble wrap. It is free and I mount it with spray glue, then trim to size. Works great. About 1/16 inch thick.

Re: vacuum chucks

George

I like the Foamies with the adhesive backing. I've used them for years with no issues. I recently bought a ten pack of them online. Could be a lifetime supply!