I finally got my vacuum bag system set up (mucho thanks to
joewoodworker.com). I've done some veneering, and now I'm thinking about
making a vacuum clamp.
I had the thought that I could drill a hold through my solid maple bench top
and thread an NTP male quick release onto the bottom. Then take a piece of
MDF and drill a hole though it. Put some neoprene tape along the edges on
both sides. Then whenever I want to vacuum clamp something, I'd blow out
the hole to clear any dust/debris that might have collected, attached the
vacuum pump, put the MDF over the hole, and the piece to be sanded/routed on
top of the MDF. Then turn the pump on (the pump is 3cfm continuous duty
rated).
Am I missing something? Ideally I'd have a foot switch to release the
vacuum pressure, but as far as I can tell it should work. Thoughts?
MDF works just fine if you finish it. I used spray lacquer on mine. I drew
a vacuum last Saturday and the piece is still locked down as tight as can
be. Based on my experience, you should incorporate some type of release
valve. I will probably re-design mine so that the vacuum that holds the mdf
to the bench and the vvacuum that holds the workpiece are two separate
lines.
--
dbchamber at hotmail spam dot com
Remove the spam to reach me
> Don't use MDF - it's much too leaky. Instead make your block of
> UHMWPE (ultra high molecular weight polyethylene). It's available
> from most woodworking ssources. It's not cheap but it /works/.
David Chamberlain wrote:
> MDF works just fine if you finish it. I used spray lacquer on
> mine. I drew a vacuum last Saturday and the piece is still
> locked down as tight as can be. Based on my experience, you
> should incorporate some type of release valve. I will
> probably re-design mine so that the vacuum that holds the mdf
> to the bench and the vvacuum that holds the workpiece are two
> separate lines.
The two-line approach sounds good. I think I might have to build
a few more 'pucks' to play with. I normally use multiple pucks to
hold a workpiece; and for production runs have had to make a mask
of 1/8" hardboard with cutouts for the pucks to keep them from
shifting when the workpiece is removed. A second line would make
that unnecessary - but would double the amount of tubing in the
work area; and would require a second vacuum source.
I started out with UHMWPE and have never had a problem; but know
a number of people who've used MDF and seen poor-to-terrible
performance. I suspect that they just didn't seal the MDF as
thoroughly as you did.
--
Morris Dovey
DeSoto, Iowa USA
It sounds like this would work great. You could make various sized
pieces of MDF for clamping various sized boards.
Joe in Denver
My woodworking website:
www.the-wildings.com/shop/
"Bestest Handsander" <[email protected]> wrote in message news:<[email protected]>...
> I finally got my vacuum bag system set up (mucho thanks to
> joewoodworker.com). I've done some veneering, and now I'm thinking about
> making a vacuum clamp.
>
> I had the thought that I could drill a hold through my solid maple bench top
> and thread an NTP male quick release onto the bottom. Then take a piece of
> MDF and drill a hole though it. Put some neoprene tape along the edges on
> both sides. Then whenever I want to vacuum clamp something, I'd blow out
> the hole to clear any dust/debris that might have collected, attached the
> vacuum pump, put the MDF over the hole, and the piece to be sanded/routed on
> top of the MDF. Then turn the pump on (the pump is 3cfm continuous duty
> rated).
>
> Am I missing something? Ideally I'd have a foot switch to release the
> vacuum pressure, but as far as I can tell it should work. Thoughts?
Bestest Handsander wrote:
> I had the thought that I could drill a hold through my solid
> maple bench top and thread an NTP male quick release onto the
> bottom. Then take a piece of MDF and drill a hole though it.
> Put some neoprene tape along the edges on both sides. Then
> whenever I want to vacuum clamp something, I'd blow out the
> hole to clear any dust/debris that might have collected,
> attached the vacuum pump, put the MDF over the hole, and the
> piece to be sanded/routed on top of the MDF. Then turn the
> pump on (the pump is 3cfm continuous duty rated).
>
> Am I missing something? Ideally I'd have a foot switch to
> release the vacuum pressure, but as far as I can tell it
> should work. Thoughts?
Don't use MDF - it's much too leaky. Instead make your block of
UHMWPE (ultra high molecular weight polyethylene). It's available
from most woodworking ssources. It's not cheap but it /works/.
You don't need to drill your workbench to do this. I have a web
page at http://www.iedu.com/DeSoto/assembly.html that describes
how to build the kind of clamp you're describing.
BTW, I use an old recycled refrigerator compressor to provide the
vacuum for my CNC router. It works /well/ (and the price was right!)
--
Morris Dovey
DeSoto, Iowa USA