Practicality of making a vacuum bag
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Anyone making your own vacuum veneering bags? I am contemplating buying a sheet of vinyl or polyurethane and seaming it myself. Having never done this, I wonder how difficult it might be to fold and glue a seam and install the bag valve? Is this a 2 person job?
Greg
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Exo 35:30-35
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Replies
Greg:
I've made mine forever. Try spending some time on the Joe Woodworker site http://www.joewoodworker.com he's got some great information there.
My only advice would be to make sure you've got adhesive that is compatible with your bag material and make sure that you work in an extremely well ventilated space, some of the solvents are pretty nasty or at the very least flamable.
I like heavy vinyl as it will stretch over shapes and is a bit more resistant to leaks caused by sharp corners.
Best of luck,
Madison
I've heard from several folks that a waterbed mattress makes a good bag. I have one but haven't yet embarked on this adventure, yet.
Regards,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
I have made a two bags, the largest about 54" x 72" , large enough to do a dining room table top. I used some vinyl material purchased from a fabric store. I think it is about 12 mils thick. Finding a glue that works was the hardest part. I fold the end shut and clamp with boards, and get very little leakage. My pump is an old medical vacuum pump that I found. I use a programmable light timer that turns the pump on for 2 minutes and off for 5 - 7 minutes. This takes a little trial and error to set up by monitoring a vacuum gauge.
I have used mine about 25 times and it is still holding up. I think Joewoodworkers site has a source for a vinyl glue.
Robert
I made one out of an old water bed mattress.
Jigs,
Can you tell us more about it? As I posted, I also have one and would like to look into making a press with it.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
I just slit one end. Made a long clamp from two 1 X 6s with a 3/4 X 5/16 dadoes in them about 3/8 in from the edge, and with 1/4-20 bolts every 8-inches to clamp it down.
I'd fold a couple of pieces of 1/-2-inch dowel into the slit end to close it, and clamp it tight. I used the fill/drain hole as the vacuum port.
So with a few pieces of scrap wood and a vacuum pump and you're rocking and rolling!?
What would you recommend for a pump?
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
If you have shop air, check out joewoodworker.com venturi systems.
I think they also sell vacuum pumps.Greg
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Greg,
Thanks man for the link. Lots of info. to digest.
Regards,Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
My room mate at the time was a mechanic, and had a pump for evacuating airconditioners. I used it, and his manifold setup.
Jigs,
I know diddly-squat about veneering, much less about vacuum veneering and as such I'll need to do some research on it. But it is something I would like to do.
One thing I'm curious about: Does the size of the bag have any influence on the size of the pump or am I amplifying my lack of knowledge? Could one start out with a relatively simple setup with a small bag to get his feet wet, so to speak?
Regards,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Edited 4/29/2008 8:30 am ET by KiddervilleAcres
You most certainly cold start with a small set up.
The bag only needs to be big enough to fit the piece you want to veneer. The pump only needs to be large enough to evacuate the bag you have, and even a small pump would eventually do it.
I have seen small set ups on ebay that were a small bag (24 X30), and a hand pump.
If you have large compressor, there are venturi devices that generate vacuum from air flow. And, if you have a good water supply, there are "Chemists Aspirators", that use a venturi to generate vacuum from the water flow.
Well blow me down as Popeye used to say.
I was just talking with an old friend who is a plumber and familiar with vacuum pumps. He suggested that I retrieve an old compressor from a discarded refrigerator (I know where there are several of them - FREE), connect the water bed matteress (Which I have - FREE) to it on the vacuum side - done. Well almost anyway. For a few dollars more he will make one for me.
Of course it might cost me a gun rack but that's cheap enuf for me to do. Soooooooo, I guess that answers some questions, eh?
Most appreciative of your help,
Bob @ Kidderville Acres
A Woodworkers mind should be the sharpest tool in the shop!
Edited 4/29/2008 10:22 am ET by KiddervilleAcres
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