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Press for laminations5/18/18
I'm wanting to fabricate a press for rails and stiles that would probably use modified bar clamps for economy.
What I'm primarily wanting to glue-up in one pass for instance are five sets of three sticks
What would be great is if I could construct something that I could also use for beams and columns (glu-lams of larger material).
I'm curious as to what others have for this purpose and would welcome photos of your shop-made press.
In the first real shop I worked, they had an 18' long glue up 'table' for handrail laminating. 2 x 4 horizontal struts, White Oak, coming out from the wall about 24". 45 degree angle 2 x 4 struts below to the wall for support. These were about 8" on center, and leveled very accurately, with long straightedges. About 12" from the back wall was a 2" thick x 3" tall hardwood running the 18'. It was lagged to the Oak struts and made a good 90 degree face. Everything was waxed with Gulf Paraffin cakes.
It was used for the lamination to thickness of multi-ply handrails. A dead-stop at one end enabled pushing the various butt joints together as it was clamped. We used handscrews to clamp the laminations to every strut. And then a handscrew was used to tag the laminations tight to to the 2 x 3 spine to keep it all in line - and straight.
This had several drawbacks - slow to clamp. Needed a caul on top to help distribute the clamping force. Slow to cure with 'yaller' glue. Could only do one rail at a time. Big clean up on the struts between parts. Glued some parts to the back rail or spine. Wax would get everywhere, not always a good thing with wood.
We fantasized about air clamps overhead, each with a 12" long 8/4 caul to distribute pressure and a control valve on each. Iron angle struts to minimize contact and make clean up easy. And some sort of plastic face on the 18' spine to repel glue. But the shop closed long before any of that happened.
In subsequent shops, we have made straight rail many times, up to 28', but we never felt the need for such an apparatus. A good eye and properly prepared stock kept everything in line. We do use benches (all meticulously the same height) for long, straight glue ups, but a good eye still is needed.
Today. I would do this on the 9' bench, stacking and gluing and make one tall stack, sitting on equal thickness blocks on the bench to hold the clamp handles off the bench. Clamp it with pipe clamps opposite sides, about every 8-10". Let it cure. I will buy you lunch if they are not all dead straight - assuming you prepped the material properly - faced and edged on the jointer and then planed.
What you described in your last paragraph is what we're doing now on 10' tables.
I was thinking of doing something like what you described in your first paragraph, using one of our long walls, and moving to some kind of "bench" set-up and get off the tables.
I too like air and hydraulics, but I'd like to keep it simple. I'd like to get away from using so many clamps - maybe a steel caul with a slight curve, laminate-faced.
I'm also starting to think RF for the volume I might need.
Thanks Dave for taking the time to respond,
It is all about volume. Enough of those things and the pneumatic cylinders get more attractive. They would squeeze out the glue, then keep the pressure on. Pipe clamps may have XXXX lbs of clamp force when first tightened, but that could drop to XXX after some of the glue has drained out.
It would be nice to have the rack, but maybe two sided, and with shorter clamps (most of mine are 42" min, up to 52" or 100" - hard to stick up in the air). Two people, working together should be able to run 5-6 parts in about 30 mins. 2-3 hrs later, and change them around.
I got an idea. Why don't you do some experimenting on your project, and post back and let us know what you learned. Then we don't have to go spending time and money on half a system.
Best of luck on it.
I thought I'd followup on my search for ideas on a press to laminate boards by showing what I've done so far.
It's a work in progress. We can laminate up to 12' long sticks. Wanting consistency, we're using a torque wrench at 25 ft lbs, probably about a full turn more than what you would do with a hand clamp.
As you can see, we have to beef up the tube steel clamps on the 'X' axis. It might be better to have two-points rather than a single in the middle, but a factor in the decision to keep it in the middle was reducing the open time of the Tite Bond III.
There are other changes that need to be made; it's not the end result of what we need, but it's a good starting point.