My dies in the pro tools bender were doing the same thing. I cleaned all dies and started using axle grease on all surfaces. Also, I clean tubes before bending and after because of the grease. Hope this helps its a little more work but worth it.
Thats awesome! Actually I started doing pretty much the same thing. I clean the tube with a solvent and get off all the oil and dirt. I then sand it down with some 400 grit sand paper which really just lets me feel for any gouges or burs. Since I work in a machine shop I started useing way oil on the tube, which in my case we use vactra. The way oil has more beeswax in it so it sticks to the tube well and is very easy to clean up before you weld.
