Another clamping trick

[Jamie Buxton]

My conversation in another thread with John Milunias brings to mind a related trick for clamping stuff together. We all know how to clamp boards together when they meet at 90 degrees or 180 degrees. We put clamps on the outer edges of the boards, and the boards transmit the pressure to the glue surface. However, clamping things at other angles is trickier. When you attempt to do the same thing with the clamps, the joint buckles.

One solution is shown below. The yellow things are the workpieces. Maybe they're solid lumber in a coopered panel. Maybe they're big plywood panels in a corner cabinet. The blue things are shop-built hooks. The two big arrows are where you apply the clamps. Notice that a line between the two arrows passes through the middle of the glue surface, and at right angles to that surface. That is, the clamp's pressure is applied exactly where you need it.

I make the hooks out of whatever scrap plywood that's hanging around. I tend to make them for a given gluing operation, and pitch them back into the scrap pile when I'm done.

Jamie

[Bill Arnold]

Another approach to gluing mitered pieces is shown in the attached graphic. Bring the two pieces together with the outside up. Place a piece of clear packing tape along the joint and press it firmly to remove all air bubbles. Flip the two pieces over and brush glue along the inside of the joint. Lift the joint together and hold it in position with blue tape. The packing tape will apply pressure as the joint is 'folded'. The graphic shows a 90* miter, but this process will work on any angle.

[Dave Moran]

Jamie, your fixture is great for production where the stock is always the same size, a slight modification, no hooks, makes them less job specific, the old way is a "paper joint" where you glue the fixture, to the stock with a piece of craft paper, a grocery bag will work if you stay away from the ink, the paper lets you take the joint apart easy. another is again without the hooks, clamp the fixtures to the sides, then clamp the fixture together to clamp the joint.

[Jamie Buxton]

Jamie, your fixture is great for production where the stock is always the same size, a slight modification, no hooks, makes them less job specific, the old way is a "paper joint" where you glue the fixture, to the stock with a piece of craft paper, a grocery bag will work if you stay away from the ink, the paper lets you take the joint apart easy. another is again without the hooks, clamp the fixtures to the sides, then clamp the fixture together to clamp the joint.

Dave --

I've tried making the hooks without the hooks at the ends, but found that when I tightened the clamps, the hookless hooks tended to slide to the joint.

And this hooked solution needn't be a production thing. They can be cut out in just a couple minutes, so they can be used once and thrown away.

Jamie

[Dan Chouinard]

Jamie,
I modified your hook clamp today and it worked great. The mahogany corner vanity had 9" flat panel wings on both sides that will return into the side walls. The end panels were 28" high so instead of making individual hook clamping jigs to pull the face frame and panels together I made a 3/4" plywood jig, 28" tall and 8" wide. Ripped a 2" piece of ply at 45 degrees and 28" long and screwed it to one edge of the 1st piece of ply forming a lip perpendicular to the face frame. The jig was clamped flush to the end panel stile with square edge, placing the lip 1" back from the glue joint. This leaves enough room to get a wet rag in there to wipe off the squeeze out. Used 5 biscuits, pushed the two stiles together and put on 5 clamps from lip to the inside edge of the face frame stile. Worked like magic, tight with perfect alignment.
Thanks for the idea,
Dan

[Frank Drew]

I've tried making the hooks without the hooks at the ends, but found that when I tightened the clamps, the hookless hooks tended to slide to the joint.

You have to let the glue dry, then it works without the clamping blocks slipping.

If, say, you want to glue up all four parts of a mitered frame, Dave's suggestion to brown paper glue the offcuts from the mitering to the work is just the ticket.

[glenn bradley]

Cool idea Jamie. I have lots of scrap around that could be quickly built to this purpose and then knocked apart and used again for another variation. Good stuff. On smaller joints I just double tape blocks with the appropriate angle to position the clamping point but for many things I can see going to this method.