It’s been a while since I made the long wooden clamps and I’ve used them in a few projects, but the truth is that, as I’ve commented on several occasions, these bar clamps have some problems that can make them difficult to use in our woodworking projects.
I’m not saying that it’s not worth the effort to make these wood bar clamps, because if we can’t buy long bar clamps, these long wooden clamps will be very useful in our shop, but it is necessary to follow a simple procedure to be able to use them so they clamp correctly. And you also need a few cheap metal clamps like the ones I have.
So, let’s see how to use these long woodworking clamps.
The problem with these wood bar clamps is that when the board to be glued is pressed, the block at the end of the threaded rod, which pushes the board, tends to lift up, and that can lift the board in the area of contact with the block.
And the same thing happens to the other fixed block that serves as a stop, causing the board we are gluing to lift as well. If we do nothing and let the glue dry, we would probably get a somewhat curved board that would be difficult to straighten.
With a few of those cheap little metal clamps and some wood strips we can solve the problem and keep using the long woodworking clamps until we can buy good quality ones. This involves placing a wooden strip diagonally between the blocks on the boards to be glued. I am going to press these strips with a pair of metal F clamps, as shown in the picture . And I also have to tighten the wooden blocks of the long clamp. And now I want to loosen a little bit the clamp 1, the 2 and the 3 as seen in the picture.
Next I have to loosen the wood bar clamp a little on 4.
And I’m going to tighten the metal F-clamps on 5 and 6 a bit. This way the board we are gluing should lie flat as it is pressed between the wood clamp bar and the wood strip.
If we did not tighten too much on 5 and 6, we can now tighten the long bar clamp hard on 7 to clamp the boards to be glued. And now we can tighten the metal F clamps on 8 and 9, to make sure that nothing will move.
All we have left to do is to repeat the same with the other bar clamp and hope that the board we are gluing will be perfectly flat and smooth.
I also have an post on how to make long wooden bar clamps that help keep the board flat on their own.
Another problem we can have is that the glue sticks to the wood of the clamps and the wooden strips. We can protect them with a few pieces of newspaper and so we will only have to worry about sanding the pieces of paper that may be glued. Another solution I tried recently is to apply cabinetmaker’s wax to these wood clamps, and it seems to work quite well, although it can be absorbed by the board and give problems when varnishing the wood. Some people recommends to put a plastic film on the top surface of the bar clamps so glue won’t stick to it.