On Aug 17, 12:51 pm, Maxwell Lol wrote:
writes:
Two problems:
1. Marking up. The vertical edge of my piece of wood is cut by hand,
so it won't always be exactly square to the bottom horizontal edge. So
if I use a 90 degree square from the vertical edge to mark up the
horizontal join cuts, they won't always be exactly parallel with
bottom edge.
2. It's difficult to cut in a straight line!

Any tips? Should I be using a saw guide of some kind? I have a feeling
I will get better results just cutting one piece of wood at a time,
instead of trying the two clamped together trick.

You have two choices - by machine or by hand.

The cheapest "machine" jig for making box joints I know is a router
and a set of templates. It's about $25 by Woodhaven:

http://www.woodhaven.com/SearchResul...CategoryID=252

You also need a router bit and guide bushings.

If you do it by hand, then you will need to practice. You need to
learn how to draw a thin line, and saw so you just follow that line
exactly.

Also make sure all ends are square and parallel.

I have a handheld router, but I thought I would need to invest in a
router table to do this. I'll look into the options.

Squaring off is pretty difficult when you're using a handsaw. I think
this was one of the main problems with my test run.