long wooden bar clamps? - Woodworking Talk

btyirin · 11-03-2008, 06:06 PM

Hey guys,

Question......I have a bunch of long wooden clamps I made with 2x4s and 1/2 inch threaded rod. the rods are 12 inches long. They range from 53 inches down the 30 or so. I made them to act as a veneer press. I never cut a relief curve in them though and I plan on doing that tomorrow. Does anyone have any experience with the these and how much a curve is good. being as I have different lengths of clamps I'm thinking I should use a percentage of the length to figure the amount of curve.

Any thoughts?

Brian

Ken Johnson · 11-03-2008, 07:41 PM

Brian,

Can you post some pics? I can't picture what you're trying to describe.

steve mackay · 11-03-2008, 08:43 PM

No idea BUT . . . what flavor wood are you useing ?

btyirin · 11-03-2008, 09:08 PM

I guess that was a bad description on my part. Here are my clamps. I have read of people cutting a curve in the clamping faces so that as you apply pressure the 2x4's will bend and put equal pressure on the work pieces. I've never scene one in person before though.

BHOFM · 11-04-2008, 03:11 AM

I would put a metal strap on the back side with a
tensioner. Make them adjustable.

Tony B · 11-04-2008, 08:15 AM

I would use 1/8" per foot for general clamping.
I'm not sure that I would make any kind of press for veneer unless I could make perfectly flat surfaces with a good grade of hardwood and a cabinet grade of plywood.

I have never used a press for veneer, only for cold molding plywood curves.
Then again, I dont do all that much veneer work

btyirin · 11-04-2008, 04:58 PM

Thanks a lot guys. I'm not using them for veneer. I built them to glue up the 1/4 plywood to my table tops. Its kinda like veneer but with a 1/4 inch it's a whole lot easier. But I had a small problem last time getting even enough pressure for that task.

General O · 11-13-2008, 10:26 PM

I don't know if it is any help. I just use alpha-clamps for my clamping projects.

Gerry KIERNAN · 11-14-2008, 10:52 AM

Just a thought here. Put your clamps on a panel and tighten them to what you figure will be your normal clamping pressure. Take a feeler gauge and measure the amount of bowing along the length of your 2 X 4 pieces. They may not all flex the same amount. This will give you an idea as to how much you will need to compensate.

Gerry

Tony B · 11-14-2008, 05:31 PM

Use the clamps as intended and where ever you see a space, tap a small wooden shim under the clamp.

Gerry KIERNAN · 11-15-2008, 10:15 AM

Quote:

Originally Posted by Tony B

Use the clamps as intended and where ever you see a space, tap a small wooden shim under the clamp.

"Excellent Smithers"

Gerry

KevinK · 11-19-2008, 02:10 AM

I believe if you want to use then as a veneer press you want to sandwich your piece between two pieces of plywood or equivalent and then apply the clamps around the whole thing

Good luck
Kevin