It wasn’t long after I started working with pallet wood that the need arose for the pallet planks to be glued together. Up to four planks side by side was OK as my clamps were big enough, but anything more than that I and I was stuck so to speak!
It wasn’t long before I found myself consulting the University that is Youtube for ideas, in the end I used several ideas to come up with the finished items. My criteria was that I should be able to clamp up to 10 pallet planks side by side. The clamps should be able to exert downward pressure to stop the planks buckling and also horizontal pressure to push the planks together. They should also be relatively easy to build and should be constructed from wood I already had, pallet wood!
As you can see from the picture below the clamps are constructed from the thicker pieces of wood found on some pallets, I needed 6 such pieces and fortunately I had them. First job was to decide were to drill the holes for the pins, each pair of bars would use 2 pins. Below the bar has been marked out with 7 pilot holes which will be made much larger later for the pins. One of the problems with this wood is that it has a large number of nails embedded in it, these can’t be removed because they have been cut flush to the wood when the pallet were disassembled. With this in mind the holes have to be drilled so the nails are avoided.
These wood gluing clamps have been made in matched pairs mainly because of the nail problem previously described, so all the way through the build the clamps were marked as 1a, 1b, 2a,2b,3a and 3b. So next the tow bars 1a and 1b were clamped one on top of the other. Then the pilot holes were drilled through to the bottom bar, this ensures correct alignment of the holes in both bars. The same process was applied to the other two pairs of bars.
Now all of these pilot holes needed to be drilled out to 25mm so the pins would slot in. I used a 25mm forstner bit in my pillar drill to drill out all of these holes. It took a while because there are 28 holes in all and the bars are quite thick wood.
Now the pins had to be made before the project could move forward because the bars need to be held in alignment on top of each other in their matched pairs. The pins are made from an old broom handle and are around 6 inches long. With these made they could be inserted in the holes to hold the bars in place. In the photo below you can see two bars with the pins in place.
Horizontal pressure sorted now for the vertical downward pressure
OK so the horizontal pressure problem is almost sorted, now to address the vertical downward pressure. I decided the way to do this was to have a handle at each end of the bars with a threaded rod fixed into the handles. The threaded bars would screw into a fixed nut on the bottom face of the lower bar. As you screw the bar to tighten, it forces the the upper bar downwards onto the lower bar.
In the photo above you can see the handles with the threaded bars at each end of the wood gluing clamps. The photo also shows the pins inserted and the 3 sets of wedges that are used to help exert the horizontal pressure.
You may be asking yourself, why go to all this trouble when you could buy some sash clamps or pipe clamps to do the same job. Well the simple answer is that I want to upcycled materials as much as possible in everything I make. Apart from the threaded rod, nyloc nuts and t nuts, everything in these 3 pairs of wood gluing clamps is upcycled.
I will write another post soon to describe how these wood gluing clamps actually work.
There are more images available showing how these clamps were made, too many to include in this article, you can find them here Wood Gluing Clamps Image Gallery