vacuum tables

[Regis]

Skip and Bill brought up vacuum tables in another thread but it was not carried on (guess they didn't want to hijack the thread). BUT, that is something I have an interest in for forming holsters. I'm relatively sure the commercial tables will work but, has anyone made (or made use of) smaller versions or even the vacuum bag type?

Does the very moist (perhaps wet) leather affect/harm a vacuum pump? How long must you leave it under vacume? Does the bag type with shop vac pull enough vacume?

My 4 or 5 a year would not justify a commercial vacuum table.

Thanks

[Skipknives]

How i made my vacuum table:

3' X 2' (ft) piece of 3/4" inch ply-wood

3' X 2' (ft) piece of 1/8" inch lexan

I drew a 14" X 16" rectangle on the ply-wood

inside that area cut parralel lines about an inch wide and one inch spaced apart with a router.

only cut in half the thickness of the board (set the depth shallow)

then go back over the same area doing the same thing on the lateral,,forming a grid that resimbles a checker board.

but all the cuts join forming a grid,,the one inch spacing between lines now is transformed into 1" X 1" areas that will suport the clear lexan cover over this area.

Note*cut this rectangle to the left or right of center because the final product will sit on a bench top and a vacuum pump will sit on the other end.

at the corner of the grid that is clossest to the center of the board cut a connecting channle three to four inches long that extends out side of the grid but is connected.

seal the cuts in the board with a water sealant paint so while under a vacuum air won't be sucked in through the pores of the wood.

when that is dry place the clear lexan over the board and with a marker map out a grid of dots spaced 1/2" apart within the grid.

at the other end of that channel that extends out side of the grid mark one dot.

these dots will need to be drilled for air to pass through. Drill a hole at each corner for screws as well (inset about 1" inch in from the edge)

when all the holes are drilled lift off the lexan and clean up your mess lol

in that one stray hole that was drilled out side of the grid a air fitting will need to be attached.

(vacuum bag supplies have thies fittings that come with rubber washers) the fitting will have threads cut in the end for a hose to attach.

get a tube of sillacone and squish a bead on the board around the grid and include the stray hole and channel where the fitting will be.

make sure it is one compleat circle without any gaps,,set the lexan on the board squashing that bead of silicone and secure the edges with the screws. (have that air fitting on the lexan first cuz there is no going back after the silicone is dry.

you have formed your vacuum chamber.

go to the art store and buy a 16" X 18" canvas on a frame. from the back poke a hole in the canvas and cut away all the cloth that is not covered by the frame this will be the lid of your vacuum table.

on the e-net buy two or three yards of streach-membrain from aero-space composits it has a 400+ % stretch memory used comomly on vacuum tables to do odd shapes when applying vernieer to wood. the cost is under $20 for several yards,,it is transparent green and looks like shrink-wrap,,but mush tougher. wood supplies might also have it.

loosly cover the frame with the membrain and staple it to the frame (save the rest of it for the future)

place the covered frame on your table over the holes and square it up. (only the air-fitting hole won't be covered)

using a marker draw around the frame,,then set the lid to the side.

go to the hardware store and buy a roll of weather striping with adheasive back. and apply a strip to the table inside the rectangle you drew on the lexan. at the corners instead of cutting the strip apart,,cut a "V" notch and change directions forming the rectangle on the lexan.

at each corner use some of the left over silicone and dab it into the "V" notch and the start/finishing point and let it dry.

when the vacuum pump is turned on set the lid on and press slightly on the frame until the vacuum catches up.

Now go to the sewing store and buy a yard or two of "batting" it is 50% cotton and 50% nylon and only an 1/8" to 1/4" inch thick.

cut a section of it and place over the holes on the table (inside the weather stripping) this will form a small passage for all the air to be vacuumed out. without it the membrain might trap pockets of air.

I'll go out to my shop and snap a couple of pictures and add to this,,give me a few minits to come back.

[Skipknives]

ok here are 5 pictures of my dusty vacuum table.

note the inline moisture catcher to protect the pump from water droplets.

pardon my spelling it was never my strong point.

http://i196.photobucket.com/albums/aa55/skipknives/v1.jpg

http://i196.photobucket.com/albums/aa55/skipknives/v2.jpg

http://i196.photobucket.com/albums/aa55/skipknives/v3.jpg

http://i196.photobucket.com/albums/aa55/skipknives/v4.jpg

http://i196.photobucket.com/albums/aa55/skipknives/v5.jpg

Edited November 7, 2007 by Skipknives

[Skipknives]

Regis,,dont use a vacuum bag for most sheaths or holsters cus the bag will contract and a wrinkle contacting the leather leaves a mark.

the table will remain flat and easyer to control the wrinkles.

Edited November 7, 2007 by Skipknives

[Regis]

Skip,

What a great answer. This is definately for me to print and start accumulating parts.

Thank you,

Regis

[Skipknives]

whee haw glade you can use it

if you die with your secrets they go too,,lol

[Billsotx]

Skip,

Thanks for sharing. The photos are great; they fill in the blanks in my miniature military mind. I appreciate you taking the time to describe all this and making the pix.

regards,

~Bill

[Skipknives]

billsotx,,howdie, thank you

I went to your web site and saw your work,,

do you use a vacuum table?? or do you do it by hand??

[Billsotx]

I do it by hand but I've been thinking about either a vacuum device or a 20 ton shop press. I can use the vacuum device for my woodwork so it's got my interest. Again thanks for sharing and giving your time. Much appreciated. ~Bill

[Jordan]

great howto, I don't know if it is a problem but to help the staples not pull on the sheeting and eventually tear it you could use the thin strips of dense cardboard that upolstery shops use folding the material around the thin strips and staple through that into the wood. I am definetly going to make me one of these as soon as I get my shop area finished. Thanks, Jordan

[Romey]

Bill , you mention using the vaccum for wood, do you happen to be stabilizine wood under vaccum?

[Skipknives]

Romey I have tryed to stabilize using a vacuum and kurrs jars that will hold the vacuum for weeks.

I was using "spur-resens" because of the very thin viscosity and mixed a dye agent into it so i could map the progress.

after a week under 25inches of vacuum i only got 1/16" inch of penatration (except at faults/checks)

it would pull the air out of the wood in about an hour (no more bubbling). not much sucses.

I am trying to get a pressure chamber made from a hydrolic cylinder that will hold 5,000 + PSI (safely) and will do more tests.

[Romey]

I built a really heavy duty stablizing unit a few years ago that would take up to 6000 psi, ofcourse a three hundred gallon air compressor would only push it to about 120PSI and the vaccum part of it was a 2 piston suction run my a 2 horse motor. It would get up to 29 inches and then hold as 28. Great stablizer. the issue was the material. I exsperimented with everything except what K and G and the other stabilizing pro , that stuff is 100$ a gallon IF you can get it. But i tried everything else readily available from Minwax to pentacrel and non of it worked every good as the stabilizing matrix. In the end the hours i put into that unit, hours and money I put into using it and not being happy with it i realized i was saving money buying the block from KandG or where ever, professionally stabilize. Just my 2 cents. Its a really neat machine i bit, and just sits in a corner now...