Table as vacumn press?

[myxpykalix]

When watching Amy Devers on "free form furniture" it occurred to me while she was using a vacumn press. If you weren't using the table to cut but needed to vacumn press something using your fein vac could you use it to vacumn press something by sucking the plastic down, closing the vent on the pipe would that work? Just a thought, since I don't have my table yet thats all i can do (is dream about it!)

[ed_lang]

When I vacuum press parts, I use my smaller high vacuum (29") pump and a closed bag with platten inside. I would not expect the Fein Turbo III's I have, would not be able to pull glue joints tight.

I have not tried it, so who knows. I bet someone here will give it a try and report back.

A 4'x8' vacuum press sure would be nice.

[rhfurniture]

look at www.joewoodworker.com (http://www.joewoodworker.com)
I think a gast type would work but not an overblown vacuum cleaner.

r

[billp]

I also think a smaller, high vacuum pump would work better, but after seeing how a bunch of guys are using a simple Shopvac, and some painter's drop cloths to build 33'hulls for racing sailboats, I think there is a lot of room for "testing"in this area.....http://www.multihulldesigns.com/pdf/cm33.pdf
PS. In addition to the standard vacuum pod/puck demo we usually do at the Camps, we'll be bringing around a small version of a vacuum bag setup to explain how some 'Botters are incorporating bagging technology into their work this season..

[beacon14]

The Fein vacs will acheive 5 inches of mercury, maybe a tad more with zero leaks. The Gast type high-vacuum, low airflow pumps like those used with vacuum veneering will pull 25 inches of mercury, and are typically used with cutoff switches which maintain around 20 inches or more.

My own system leaks a bit so I press with between 15 and 20 inches of mercury, and it's the lowest I would consider adequate for pressing veneers flat.

In short, the shopvacs don't have enough vacuum power to be used for veneer pressing, although they might work for some basic laminating tasks where the materials are nice and flat to begin with.

[waynelocke]

I agree with David, although, it probably would depend on the glue, the substrate and the veneer. If you were to use epoxy and had a good flat substrate and flat veneers you might get by because the epoxy does not require the intimate contact that the PVA and resin glues requirebecause of its good gap filling properties.

Given the expense of the bag and the materials, spending the money on a high vacuum pump shouldn't be a killer. You can find a used pump for less than $75. Dealing with veneer bubbles and delamination exceeds that cost real quickly.

[trakwebster]

Could anyone here point us vacuum newbies toward information about using vacuum bags as gluing clamps?

I've heard that it can be done, but cannot exactly picture how. I do have a very small vacuum pump, which will create about 12 lbs of pressure here in our town at 4000 feet altitude. In theory, on a glue joint which was 4" x 6" that would be 288 pounds of clamping force. I doubt that I'm applying more than that using hand clamps, so perhaps it would be workable, and it might be useful where hand clamps are clumsy.

It makes me want to experiment, but how does it work?

[billp]

Arthur,
You can get some very good info from two web sites; the above mentioned www.joewoodworker.com (http://www.joewoodworker.com) , and a secondary site created by the same people; www.veneersupplies.com (http://www.veneersupplies.com) . They have good information, and are also a source for all of the parts and fittings you'd need to get into using vaccum...

[beacon14]

There is also a lot of good information at

Vacuum Pressing Systems (http://vacupress.com/index.htm),

They just about started the small vacuum bag movement years ago and have an excellent forum on veneering and especially vacuum bag techniques.

[trakwebster]

Thanks fellows, I'll be studying these three.

I've already peeked briefly at them, but one question comes to mind, for those who have used vacuum clamping to glue parts together ...

When using this method, why don't you have a lot of squeezed out glue sticking the workpieces to the 20-mil bag and anything else inside the bag?

[les_linton]

Arthur,

I have been using one of the small Vacu Press systems in Davids post for about 4 years with great results. The forum that Darryl Kiel runs on that site is a wealth of infomation also.

"glue sticking the workpiece to the the bag". Well, that's about the same with any new tool, once you learn to apply the correct amount of glue for the project, you will not get much coming out.

Depending on the project, I will often use a top and bottom platen made from MDF slightly larger than the project and those I spray with lacquer and then wax. That way any glue that does come out ends up on the waxed pieces and comes right off.... generally.

On small projects, I simply put wax paper on both sides and that keeps every thing from sticking. Sounds like a lot of work, but once you get a few things set up it is pretty easy.

Les