Thread: Vacuum Press

P,

Hmmm... If I can't copy it from entirely scrounged materials, I don't consider it to be cheap

Thats my definition of cheap, says I.

I was thinking of using the bought bags and hand pump for a while then taking a deep breath and cutting out the valve and welding it to a bigger bag that I had made on the cheap.

I was thinking of making bags from heavy plastic, the kind the tent people use for windows in cafes, and doing a loooong overlapping side seam with a tube sealed in it, which was connected to a bicycle (car) tyre stem and valve.

Would take a bit of jiggery pokery, and half a tube of silicone, but I don't see why it wouldn't work?

How does the air get into a bicycle pump? Is it possible to reverse the washer in it, to make it suck?

That sounds like good cheap fun! (and bike pumps used to be soo easy to steal, err, I mean borrow! )

P

Ahhh, I looked into making my own hand pump... The one way valve cost about $30.

All the other parts were standard PVC fittings. I can dig out the plans if you want.

However, the hand pump all industrially made would pull a vacuum about the same as the Vacuvin wine pump (but cost a lot more once you included all the fittings etc).

The wine pump I bought was $30 and that included 2 seals.

Clinton, if you want to make a bigger bag - don't cut the bag up. A two pack of seals costs about $10 from your local Kitchenware supplier.

In fact, why buy the carbatec one for $100 when all you want is the pump and seals - which cost $30?

Cam

Originally Posted by bitingmidge

1) Find a fridge and use the bits, but I like the valves and auto maintenance of pressure that the plans provide. Initially almost free.

This is where an air-con comp beats a 'frig hands down.

The attached pic shows the job I'm planning on using, and indicates the normal flow direction. The filter, radiator, etc can be stripped out for weight savings, but don't need to be removed... although I'll replace the filter (on the end marked "Out") with something to scavenge lube. The best thing are the fittings: being for air-con it's made to be serviced. You can see the shut-off valves in the pic, along with the fittings for fitting a vac-pump/gauges, etc. for normal maintenance. A simple matter so install a pressure switch and gauge in the marked fitting, et voila!

Take into account you dont need a bag for vacuuming. A 20mil vinyl sheet should be the minimun. You need to be carefull on the choice because cheap vinyl hasnt got a memory which you need for veneering. The best is 30 mil industrial grade clear urethane membrane.

The simplest way to describe a "non bag" system is to have a bench with a sheet of melamine attached with a series of shallow grooves routed to help with air removal, and have your inlet valve inserted up through the bottom and sealed. When pressing a panel, lay it onto the melamine and put your newspaper over the veneer and throw a 20 mil sheet right over the entire bench.

Now you just need to seal the edges. The best way is to have a simple frame made up with a rebate like a picture frame that has a neoprene or rubber gasket in the rebate so it slips snugly over the vinyl and bench edge and just use some hand clamps to tighten and make air tight.

I have seen a great example where the frame was anchored at the edges with rope and attached via a pulley from the celing and the bench can be used as a normal bench and when the need to vacuum arises you just lower it onto the bench. Its a simple solution for the woodie who is just an occasional vacuumer

I have never done any veneering and dont know much about it, but if you have to go the home made route then is a vacuum press really necessary. I'm thinking that I recently rang all the commercial veneer people in Sydney (the walnut table thing) and not one of them mentioned vacuum. I got the impression, not sure I'm right though, that they use mega mechanical presses. A mechanical press should be pretty easy to make, I'm thinking some recycled steel, a couple of hydraulic car jacks, some carefully shaped timber, some mdf to give a flat surface, and the top of my workbench.

Of course you could only do flat surfaces, but isnt that normal, veneer the flat bits, solid timber or laminations for the curves. Or maybe do the flat bits well, and if the need for a curved bit every arises, get it done commercially.

Any comments
Arron

Arron, vacuuming is made for curves. When you get into it you will find its the best way to laminate curves and using the same formers they lay veneer. A cheap hydralic press as you mentioned is ok for small stuff in a small workshop, but what if you want to press a table top? it has to be a humungus press. The above method i described is dirt cheap and so easy and takes up no space

If you have a car you have a source of vacuum. Most cars have a vacuum tank, surely it might be possible to hook up to a bigger tank and utilise the manifld vacuum? Old cars are easy, just hook it up to the inlet manifold, new cars might be a touch more difficult.

Big stuff is what I want it for, I've got a table thats waiting to be re-veneered and sold.

Little stuff thats curved can be pressed, but making a jig takes up too much time IMO. I'm over it anyway.
Do enough small stuff of different designs, and the vacuum press would be cost/time effective I think.
I think of all the time and MDF I'd save.

Lignum: That idea sounds cool, I could use my glue up table. Whats the "inlet valve", and what drives the vacuum?

Clinton, the valve is the same as used on a vacuum bag and you can get them cheap from cloudmaker or a West System dealer. And The vacuum will just be a venturi used of your air commpressor, thats the easiest way (and reasonably cheap) Cloudmaker and West system also sell them.

The sheet over the bench is a fantastic way to veneer and brilliant for large table tops and in my opinion so much easier and better than a bag

Originally Posted by Lignum

The sheet over the bench is a fantastic way to veneer and brilliant for large table tops and in my opinion so much easier and better than a bag

Sounds good. Is there any chance of some photos or diagrams. Maybe making it the subject of a separate descriptive post. I'm sure a lot of people would be interested.

Arron

Arron and Clinton here is an example from Vacupress (the best vacuum systems by a mile) The one featured is hinged, but works on the same principle. A seperate frame suspended from the celing would be my prefered method if you dont have alot of spare space.

And for around AUS $44 delivered quick (mine took 5 days) a sensational DVD called Working in a Vacuum, it is so facinating to watch and you will get very excited and get stuck straight into some veneering. The first 5min will give you a basic run down on veneering and then it gets stuck into the real nity gritty, great stuff The bloke who is in the DVD and runs Vacupress is Darryl Keil who writes most of the good articles for FFW.

Also this site has a brilliant forum where you will get all the information you could possibly want for veneering. Again Darryl Keil is the moderator



http://www.vacupress.com/products2.htm#fliptop





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There is an article in the most recent issue of Wood Magazine here in North America where they try a spacesaver bag for vacuum veneering. The tester said that the bags lost vacuum over an extended period of time. Their recommendation is that it works better for storing clothing.

I also did a bunch of tests on the spacesaver when we first worked on the TAP kit idea thinking they may have been able to supply us with custom bags for our purpose. Both the seal and the zip loc closure leaked on my tests. We got in touch with the zip loc distributor here again hoping to incorporate this into the design. They informed us that the zip loc would leak because the plastic lock gets distorted by the heat sealing process at the 2 sides of the bags while attaching them to a bag.

I actually found a spacesaver with an attachment for a manual pump. The pump they provided was great but again the bag leaked.

The other big problem with using a space saver is you have to somehow hook it up to a vacuum pump and not the recommended vacuum cleaner which will not pull enough of a vacuum to properly do vacuum veneering. Keeping a vacuum cleaner running non-stop under load is dangerous and can easily cause a fire. I do not recommend it.

There are no other kits out there, like our Thin Air Press system. I picked the pump and valve, the bag and the sealing tape we use after a year of testing probably a hundred different combinations. What we came up with works. We created the kit originally to teach kids how to make laminated skateboard decks so it needed to work and be easy enough for a young person to use. It is not just the pump that makes our kits work.

You can reverse engineer one of our valve systems with little problem and attach it to a larger home made bag. The valve is not heat sealed to the bag. This could be an option for making larger projects. I know it is too expensive to ship custom bags from here to Australia and there are probably lots of places that could make them there.

If you are wanting to do large veneering projects an electric vacuum pump may be the way to go but for things like drawer fronts or chair arms, small components our kits work great.

Hope this helps with some of your questions.

Ted

If anyone has a copy of Australian Wood Review, issue 49 I think. There is something about our kits somewhere in the issue. I would be totally in dept if anyone could send me a picture of it. We have been waiting here for the issue to show up but none are to be found. I have seen other issues but not this one.
The writeup is for sure not a good thing to post on a forum but if it was sent to: [email protected] it would probably not be too much of a problem.

Ted