Making a square - Joining two pieces of wood cut at 45 degrees with a circular saw

Question

I am trying to create a 90 degree angle from two pieces of wood so that I can eventually create a squared enclosure. I have cut two pieces of wood at 45 degrees with a circular saw's angle adjustment.

However, when I try to join the pieces of wood, they only meet at their tips and not throughout the slope of the cut (see photo below). Because of this, I can't figure out how to nicely join them together while ensuring that they will have a 90 degree angle when they are merged.

What is the recommended way join wood in this way to create flush 90 degree angles for a squared enclosure? Is it possible to do this with a circular saw?

Answer 1

You need to adjust your circular saw to an actual 45 degree angle, not to where the scale markings say '45'. Your speed square will do the trick.

(Or redesign for butt joints and skip the bother of a circular saw for 45s like that...)

edit to add, I tend to avoid cuts like this with a handheld circular saw because they are hard to do well, but you can improve the cut by concentrating on keeping the large part of the shoe (aka sole/deck) flat on the wood, and using something like your speed square to guide the saw to a smooth 90 degree cut.

Answer 2

I assume you are using a miter saw and not a hand held circular saw, right?

The cuts might be almost exactly 45 deg on each of the cuts, but if one of the four pieces is slightly longer than the piece opposite, then you would get exactly what you show in the picture. So you could try taking a little off the top piece.

It is not that hard to cut exact 45 deg angles with a power miter (circular) saw, but it is not as easy to get the lengths exactly right. You could measure the lengths of the four pieces and put the closest matches opposite.