Kenneth Michael Guitars est.1978
Top and Back brace vacuum clamp
The best way to get a perfect bond
when assembling contoured braces to
the top and back of a guitar is to let
the forces of nature help you out. As
you can see by the photo the glue
squeeze is absolutely uniform along
the brace. The device that is going to
be described is as simple as it looks  
--- do not try and over think it ----- it
works great!!!
The base of the vacuum clamp is a 24
X 24 inch piece of ¾ MDF. It is not
absolutely necessary but I put a few
coats of satin poly finish on the top
and edges. Sand out the finish to
smooth out runs etc. A lot of the press
bases I have seen are covered with
plastic laminate and have an elaborate
channel design routed   ---- Forget
that, it is a waste of time and $$$$.
The vacuum source is connected to the
base using a standard 1/4 “ air hose
nipple. Drill an under size hole and just
use the nipple to thread the hole. Remove
the nipple apply some five-minute epoxy
and replace the nipple --- make sure
there is no epoxy blocking the airflow
through the nipple
The clamp is simply a MDF frame 24 X 24
with a cut out larger than the largest
guitar we build, which is a J200. So our
frame is approximately 11/2” wide all the
way around --- ours has a fancy shape
because I cut it on the CNC machine.
Make sure you round over all the sharp
A piece of 10-mil vinyl is glued to the frame
with Weld-On adhesive. Duco does not
work! Yes -- I said 10-mil vinyl from JoAnn
fabrics. The idea that some special rubber is
needed is ludicrous. Professional wood
workers that do veneering for a living have
been using vinyl forever. Plus the vinyl is
transparent so you can see if every thing is
still in the proper location after applying the
vacuum. When gluing to the frame do not
stretch the vinyl – it is a good idea to stack a
few pieces of wood inside the frame to
create some relief when gluing.
This is the clamping arrangement –
spread the glue on the frame all the
way to the outside edge, a little shy of
the inside edge. Place the vinyl on the
frame (trim to size after it dries). Flip it
over  - place it of the press base with
the wood spacers as shown. Clamp the
frame to the base all the way around
You will need a roll of “m-d Building
products” 5/16” x 23/64” “D” profile
weather seal. The product # is 01025
black. I purchased mine from Home Depot
$7.00. I experimented and the “D” shape
seals the best.
The weather seal in applied to the vinyl just inside the frame opening all the way
around. Make sure the ends are cut square. Butt the ends together try not to stretch
the seal. Glue the joint with a very small amount of thin CA (super glue) Do not use
too much because that will make the joint stiff and it will not seal properly
The compressor type vacuum source
is a separate project and it is made
form components off the Internet.
There are also many continuous run
vacuum pumps available at reasonable