The truth about vacuum tables?

[Scott Shepherd]

I just smear silicone on the edges, turn it on, let it pull it slightly into the edges, turn them off and let the silicone dry. Seems to work well for sealing the edges, best I can tell.

[Jerome Stanek]

I use tite bond thinned 50% with water.

[Mike Heidrick]

I seal the edges of my LDF with the $1 gallon reject cans of latex paint.

[Jim Beachler]

I cut lots of small parts (puzzle pieces) out of 1" laminated wood. I do mine a totally different way. I use 2 ft wide masking tape from the sign shops and attach it to the board to be cut. Make sure that the tape is smoothed and securely sealed to the board. I flip it so the tape side is down and cut with my vacuum table on. I am able to control the vacuum to different sections, so my 10hp pump works for me.

[Walter Plummer]

" For someone who had not come across this it's mindblowing that a pump will create enough suck through 3/4" MDF "

It works well. It not only sucks through the spoil board to hold stock down, if you are cutting 3/4" mdf you can feel the vacuum through the sheet to be cut. On the large Komo router where I used to work they used 1 1/4" mdf as the spoil board. We use latex paint to seal the edges. 2-3 coats then put it on the table and surface it flat and clean.

[Kevin L. Waldron]

Not all vacuum is for sheet goods..... although we have large vacuums for sheet goods it is not always practical to run 10,20,30,40 hp for a small part...... Your needs as others have said ..will determine what you use..... we have a small aluminum grid vacuum that we now use on top of our large machine grid vacuum for small parts and fixtures .... including a photo of an acoustic guitar neck vacuum fixture for a small grid plate running with a 3/4 HP vacuum pump.

Kevin

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[Steve Ryan]

I use 5x12 mdf also, as well as making many vacuum chucks for my other machines. Almost all of the vacuum chucks are for a specific part and the smalles ones have peel and stick 220 grip sandpaper on the face, gasket in a groove. You can make an aux clamp for the spoilboard machines that is simple to use. I used a piece of aluminum that was a bit thicker than the workpiece. I sucked it down by itself and routed a groove on the bottom for a gasket, not very deep though. I also routed a rebate along one of the edges, not as deep as the workpiece. Put the gasket in and flip it over. Place the lip of the rebate over the edge of your part and suck it down through the spoilboard. Worked about ten times better than I thought it would.

[ron bermudez]

This is a great thread. A very informative thread for the vacuum table newb.

[AL Ursich]

Yes, this is a great thread... I cuts lots of plastic FRP tags on my hobby CarveWright and use 1/4 inch strips of double stick tape to hold the loose tags. I want to build a Vacuum sled with replaceable tops in different size tags.... I was going to use hardboard.... and drill holes to let the vacuum through for each tag... This MDF idea has legs.... I could cut the tag outline cut outs with a 1/4 inch bit and seal the channel leaving the flat area to suck the tag to the sled... WOW.... Great Thread... I have a Veneerer Vacuum Pump and will rig a vacuum switch to stop the CW if vacuum is lost...

AL

[Amazon Canvas]

Have you tried cutting thin (1/40 inch) wood veneer with your vacuum table? Small pieces about 1/4 inch by 1/8 inch, to me seem difficult to hold down. For this application, how much horse power would you need?
How about using double-sided tape?

[Mike Heidrick]

Blast from the past thread Welcome. Most folks here register their human name.

Gentle tack double sided tape or spray adhesive might work.

1/40th of an inch and those small a parts sounds like micro bit or drag knife territory and creative tabbing so you can snap out the parts.

For vacuum clamping those small parts I would be using a sealed edge LDF surfaced substrate on a grid and a big vacuum pulling through the whole LDF sheet so it acts like a large puck for the work piece. Id keep the kerf small and keep plenty of clearance and watch my speeds. I think more important than hp is the volume of air you can pull through the table and its size and the size of the workpiece and the types of cuts. Becker 10hp would be an ideal start (how big is you machine and elec service?) but Id try it with a 3hp regenerative blower vac pump. I dont think a small venturi setup is going to do it.

[Ross Moshinsky]

Have you tried cutting thin (1/40 inch) wood veneer with your vacuum table? Small pieces about 1/4 inch by 1/8 inch, to me seem difficult to hold down. For this application, how much horse power would you need?
How about using double-sided tape?

You should start your own thread but .125"x.25"x.04" is not something I'd recommend cutting on a CNC router. A laser is a MUCH better choice.

That said, if you already own a CNC router, you want a Donek drag knife probably. You can use this with a pretty basic vacuum table effectively.

[Mary Ma]

We use mdf as spoil board for vacuum tables, and when it comes to small sheets, still need to cover the edges up.

[stan kern]

some vac ideas
https://youtu.be/rSQvrg2TKzE king vac puck
https://youtu.be/i3dawJZJo4c vac press part1
https://youtu.be/nN2Hg-YDOe4 vac press part 2
https://youtu.be/z3Mlcffc3Oc vac press part3

https://www.youtube.com/watch?v=ZlavIPiicCM vac table design for holding down veneers or cardboard