If your square is not square
fixing it can be quite a challenge unless it is re-calibratable like
the Colen Clenton squares we sell. In most case I wouldn’t attempt to
fix a square that is out of square unless you are very good with a
file and have another square (that is know to be square) to help you
get the other one back to square.The
way to check a square is square you need to get a piece of wood (ply
wood is good) that is twice as wide as the stock of your square and as
long as the blade. So for a 6"(150mm) square that has a 4"(100mm) long
stock you would need a piece of ply at least 8" wide and 6" long.
Plane the 8" side straight otherwise you will get an incorrect
reading.
The adjacent photo shows how you put the stock
of the square against the planed edge and then with a very sharp
pencil or marking knife draw a line down the blade of the square. I
have put some white paper on my board to make it easier for you to see
the pencil line, but this is not necessary. Then turn the square over
and do the same from the other side of the board as shown in the next
photo. Align the square so the second line intersects with the first
line somewhere in its length. If the two lines lay directly on top of
one anther the square is square. If they don’t then the square isn’t
square and some action is required to fix the problem. The
3rd photo (exaggerated for clarity) shows this square is not square.
There is a good reason why Colen Clenton makes his square so you can
re-calibrate them back to square, because if you have ever tried to
file a fixed blade square back to square or hammer it back to shape
you will know why.
