Chris Schwarz's Blog

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.

Then what?

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

14 thoughts on “Your Carcase is Not Square. Now What?

  1. BPKeyes

    Chris –

    As a hobbyist, allow me to say how much I appreciate an article like this. For me, “truly square” continues to remain an elusive dream, no matter how carefully I approach it in my projects (and I’m talking about 1/8″ and 1/4″ problems, not 1/128″). I have so often been frustrated when I get to the part of the article that reads, “check for square,” because it never (in my limited experience) tells me what to do when I find out it’s NOT square – the instructions just assume my world is comfortably 90 degrees all the way around and proceeds to the next step, while I whimper on the sidelines and say, “Well, NOW what??” I realize that sometimes you just have to go back to square one (no pun intended). But if the author of an article on constructing a project ever gets to the “check for square” point and has a few pointers to share with the reader in case the reader’s project is NOT square, then I would be eternally grateful if Megan would allow him/her a few extra sentences to share those pointers. It helps me believe that the professional author is thinking about us hobbyists every once in a while. And that’s really encouraging.

    Love the mag. Love your work. Thanks for the blog post.

      1. sawyeredu

        When I built my carpenter’s chest many years ago, I installed the handles on an angle so that my wrists can remain straight when lifting. I have never seen anyone else do this, but it certainly helps for lifting a heavy tool box by yourself.

    1. Christopher SchwarzChristopher Schwarz Post author

      That depends on which way the trapezoid is going, and how bad it is.

      Usually trapezoidal carcases are death – especially when they are in the depth of the case. If they are in the height, I will try to correct them by planing the inside of the carcase with a rabbet plane and traversing (toward the back).

      If I can get close, then I will size the drawer to the opening and build back from there.

      I’m not going to sleep well tonight thinking about trapezoids.

  2. Bill Lattanzio

    You forgot a few of my favorites: You can never have too many clamps; I did this on my Powermatic, but you can easily get by with a handsaw; and this method works for me because…

      1. jkacerosky

        Chris, don’t you have to clamp two adjacent sides in order to transfer the non-square angle to the till? I am just not seeing how the clamps in the picture transfer the corner angles.

        John

        1. Christopher SchwarzChristopher Schwarz Post author

          John,

          The till is pulled to the proper shape by clamping it to the front of the case and capturing it between the runners the till will ride on. That transfers three sides of the parallelogram to the till.

          Hope this makes some sense.

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