Aaron,
In doing research for this o-ring project, I had read some notes on a website where a guy talked about having problems making that first .025: cut. He ended up with some uneven depth cuts, so I decided to not to try making such a large cut the first pass and did it this way: we made three identical individual cuts; each one at .O10". That gave us a depth of .010" after the first cut, .020" after the second cut and .030" after the third and final cut. The depth seemed fine; the wire just would not stay in the groove after I hammered it in there with a plastic hammer. We measured it and it was only .038"-thick... not big enough for a solid interference fit.
So, I ordered some .041"-thick stainless wire to try.
I am not looking forward to cutting that o-ring groove on the back (#6) cylinder, with its close proximity to the firewall. I guess I will replace the cutter's handles with some shorter pieces of all-thread, which will reduce the leverage on the cutter. Is that what you did?
I bought two extra cutting blades but they look different... I haven't examined them yet, closely, but they are just rectangular, with no beveled cutter side... We'll see...
What was your experience with replacing the cutter blade after it got dull?