Before starting my first engine build I needed a boring head, and decided to make one as per http://www.deansphotographica.com/ma...ng/boring.html
After finishing, to protect her from rusting I decided to hot blue her. Here the procedure that I hope may help someone.
I took a chunk of brass to get some swarf, mounted on the lathe and faced it "heavy" to get sligthly big swarf.
After getting enough swarf I took a metal cup and filled with parts to blue and brass swarf.
I put the cup on kitches fires until got the blu I want.
When reaching the blue I have quenched in unused motor oil.
The result is really nice, at least in my opinion.
The brass swarf are needed to get an even heating to the parts. Is mandatory to very good clean the parts as also a little point of oil or grease could end in a parte not blued ( don't ask me how I know it ￼ )
Hope this help someone.