By George Vondriska; Photos Mike Krivit
Clamping Techniques
Once you've crafted a perfect joint, you've got to figure out the best way to clamp the parts together while the glue does its thing. Here are tips to help you put the squeeze on four clamping scenarios.
Closing Miters
The problem with clamping miters is that the angled corners slip past each other under clamp pressure. While you're tightening one part of the frame another part is slip-sliding away. There are all sorts of specialized miter clamps on the market, but one of the simplest solutions for this slippery scenario is using a band clamp.
The band clamp completely surrounds the mitered frame. As you tighten the clamp equal pressure is put on all four corners, automatically. Since the parts are confined inside the clamp's strap, the corners can't slip past each other and "escape."
Clampless Clamping
Some gluing jobs are very simple, such as applying edge banding to a cabinet component. It doesn't take a lot of pressure to hold these parts together, but it is important that the pressure is uniformly spread down the length of the banding. In all likelihood I'm not banding one piece, I'm banding a cabinet full of pieces. That would tie up tons of clamps, and using clamps for this job would be overkill. This is a great place to use masking tape as a clamp.
Once you've applied glue and positioned the banding, stretch the tape over the banding and pull it down tight to secure it against the face. Check the seam between the tape and plywood to make sure you've applied enough pressure to close the joint. Use more tape if you need to.
Once the glue is dry, just peel off the tape.
Get Even, Stay Even
When you're gluing parts edge-to-edge it can be difficult to keep the top surfaces aligned. If, during clamping, they creep past each other by only 1/32-in. you'll have to reduce the board's thickness by 1/16-in. to get the top and bottom both perfect.
One of the easiest ways to keep everything lined up is by bridging each seam with a small clamp. First, apply enough horizontal pressure with bar clamps to lightly close the joints, then add a vertical clamp to each seam, allowing the pad to capture both sides of the joint. The real beauty of this is that once the vertical clamp is on, the joint stays aligned. When pushing and pulling the boards into alignment by hand it always seems that the joint I just fixed goes bad while I'm working on another joint.
Add Cards To A Caul
It's almost impossible to clamp the dadoes on deep cabinets and be certain you've got pressure completely across the joint. A caul, which will distribute clamp pressure, helps. But if the caul is dead straight, you're probably not getting pressure in the center of the joint. One solution is a slightly convex caul. A much easier solution comes from simply playing your cards right.
Add a couple of playing cards between the caul and the case side before finalizing your clamp pressure. This creates a distinct contact point in the center of the joint that will guarantee your entire dado gets pulled closed. So instead of an ill-fitting joint, you've got a Royal Flush.