In the process of creating the forms I will need for the inside chamber of my furnace, I created a jig and put my table saw to a rather unconventional use. This jig allows me to create almost any size circle from 2" diameter on up.

I cannot say that I created this process. I remembered seeing it documented somewhere on someone else's page. However, for the life of me I cannot seem to find that page again through any of the search engines. So I am going to document the steps here for you. My apologies to the original designer for not providing better credit.

• Here is a picture of the jig looking from the outfeed side of the saw. The center holes in the jig are spaced on 1" centers on each row, and each row is offset 1/4" from the previous. This allows me to cut any diameter multiple of 1/2" from 2" on up to about 24" with this jig.

• Start by marking the center of the block of wood that will become the circle. Here I have marked a piece of 3/4" particle board that will become a 5" diameter circle.

• After drilling a 1/4" hole at the marked center, I attached it to the jig using a 1/4-20 bolt I had laying around (actually because I didn't have any 1/4" dowel on hand). Start by roughing out the piece with large turns between passes through the blade. Then slowly start making smaller turns and continue working it.

• Here is the finished circle (with bolt still inserted).