Your Carcase is Not Square. Now What?
When you write for a woodworking magazine, there are several pat phrases that you use all the time. Such as:
1. Joint and plane all your stock flat and square. Cut all the pieces to the sizes shown in the cutting list.
2. Cut the tenons to match your mortises. (Or your mortises to match your tenons.)
3. After applying clamps, check the assembly to ensure it is square.
4. Clamp the assembly until the glue is dry.
5. Sand or plane all the surfaces to prepare them for finish.
6. Finish the project with your favorite stain and film finish.
All of these steps are hugely important, yet we often dispense with them in a couple phrases. Today, let’s talk about square carcases. They are a great thing, when they actually are dead square. Too often, something gets messed up during assembly and your carcase is rarely comprised entirely of 90° joints.
So then what do you do?
I was taught that usually you do … nothing. If you can’t see that the assembly is cockeyed with your naked eye, then it is not cockeyed. That philosophy works just fine until you have to put doors or drawers into the catawumpus assembly.
Usually with doors you build them square and oversized – then trim them with a plane to fit the parallelogram of a carcase you made. With drawers, I don’t follow that philosophy. I’ll build them out of square to match the out-of-square carcase. Like I did today.
I’m building a travel-size version of “The Anarchist’s Tool Chest” so that I can take it to shows and schools and the like. I built this chest while I was teaching a class, and somehow I forgot to square up the case after gluing it together. It’s out of square about 1/16” over its 18” depth. You can’t see the out-of-squareness, but the chest’s sliding tills won’t slide if they are square.
If I built the tills square and then trimmed them down, that would be a ton of work and material and planing. And it probably will look like poo.
So the logical solution is to build them out of square. But how do you ensure they are as out-of-square as the carcase? Use the carcase as a clamping jig. As shown above, I’ve clamped a glued-up till between its runners to pull it into the same parallelogram as the chest.
There are some other tricks involved (such as undercutting the tails to ensure the joints pull up tight), but this is the better approach – for me , at least. So next time, consider building wacky drawers for a wacky carcase.
— Christopher Schwarz