Vacume Press-What do i need

larry merlau

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Delton, Michigan
well i have a large bent panel that i will be needing to make in the near future. i have found out that the best way to go about this is a vacume press.. have seen small versions, but i need a larger one. the finished size of this panel wil be approx, 36" high and 72" wide. with a gradual bend. from what i know so far i would make a form that matches the shape needed and then glue up some 1/8" bending ply and put my veneer on it. so what do i need to make this press, how big of pump? would the one that stu found on surplus parts do it? and for the rest of the press? i appreciate all the help offered. Oh and steve, no its not gonna be your coffin. i declined making it for her:D
 
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larry, any good pump will work...........bigger pumps just pull the vacuum faster.......even a small pump will suck a bag down and hold it.......check to make sure that whatever pump you buy is rated for continous duty and will pull 25-27 inches of mercury...
the bag is the expensive part...........you can "cheep out" and use a homemade one out of vinyl and it`ll work for a few projects before you get some leaks, or you can buck up and buy a good poly bag......either 20 or 30 mil.....for most work the 20 mil is easier to work with and is what i prefer...i`ve had very good luck with qualityvak and plan on continuing to use them.....they ain`t the cheapest but they`re fair and sell quality stuff and know a woodworkers vacuum needs......tod
 
I bought 20 mil vinyl from a tent & awning supply store, and the glue and air valve from joewoodworker.com. I used joewoodworker's directions, and assembled a 30" X 48" bag for about $40. It has worked very well - with no leaks - for half a dozen or more projects so far.

The pump I have is a Gast, quarter horsepower, 120 volt one that looks exactly like the picture that Stu recently posted. Same specs, too, except mine's 120 V.

Minor gloat: I found the vaccuum pump at a neighborhood garage sale, where nobody knew what it was. I paid $10.00 for it.
 
OK tod now about the frame?

i was hoping that a frame could be made for this that would work well. a $300 bag is kinda pricey but i understand your needs. and as of right now i am not looking at doing alot of this. so maybe vinyle would work for this round. think i have aline on a pump. so now i need a frame suggestion.
 
yup, most of the time that`ll do fine.......then you need to decide if you`re going to place the form in the bag or place the bag with your glue up on top of the form.......if you put the form in the bag both the form and bag gotta be built stout! tod
 
Sorry, but repeating much of this reply in several threads - a lot of veneering questions popping up all at once! I recently took a semester-long veneering class - http://www.palomar.edu/woodworking - where we each made numerous projects including starbursts, mariner's stars and game boards. Be glad to cull my class notes and handouts and send more detailed replies to specific questions. We talked about big projects, but no one did anything on the scale you're talking about. That'll be one big a$$ bag!:D My personal experience is that joewoodworker.com is a great site for info and supplies and he has excellent customer service. There's tips there for making your own bag. If this is a one shot project, you can get by with much thinner, lesser quality bag material. I have some class notes and articles I could send you re: mechanical presses, vacuum presses and bags.

Vacuum press?. . .
If you make a bag that doesn't leak, you wouldn't necessarily need a huge pump. Once the initial air is withdrawn (which does take longer with a small pump) it shouldn't be that difficult to keep the vacuum constant. But it's gonna be a PITA to get your piece inside a bag that big, keep the veneer lined up, get the forms/cauls in place, etc. You'll probably need a positive and negative form for a curved surface. I've seen vacuum bags snap MDF forms like popsicle sticks when they're not supported. You could end up with a 72" flat panel.

Mechanical press? . . .
Seems like it'd be an easier setup. You could consider pressing it in sections rather than having to deal with putting on a 3' x 6' piece of veneer, lining it up on a wet surface, etc. Maybe like when veneering a column, you wrap the veneer around the column but don't glue up the overlap part. After initial part sets, come back, cut excess to make an invisible joint, then glue up that part.

PM me if you want more info.

Mike
 
larry, you can always make a road trip:D .......my big bag is 16ftx6ft and i`ve gotta couple of 4x8`s that`ll work just fine for what you`re doin`.....tod
 
larry, you can always make a road trip:D .......my big bag is 16ftx6ft and i`ve gotta couple of 4x8`s that`ll work just fine for what you`re doin`.....tod

thats sounds pretty inviting tod:D maybe i am wading in pretty deep:huh: i still need to know what thickness i should get for veneer tod.. i looked at the web page its offerd in 1/16 on one option// thanks mke for the info from the freshly learned student, have been to joes web page.. i got aliitte lead time on this so am just gettin research right now..
 
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