It takes a bit of trial and error. I used a test piece to cut until I got the correct depth.
@Jules Instead of a chisel I used the scrap wood and ran it through the groove to clear the built up char.
It takes a bit of trial and error. I used a test piece to cut until I got the correct depth.
@Jules Instead of a chisel I used the scrap wood and ran it through the groove to clear the built up char.