Thanks Norm! Sadly, I haven't really been practicing my engraving much, even though it would likely help considerably. I did cut a test eagle on a flat piece of german silver just to see if I could do it. I do typically make a test cut or two with a freshly sharpened graver just to see if it will behave as expected. I can't help but notice that my engraving improves somewhat from the start to the finish of a project, likely mainly from the familiarity gained using the tools.
The finish process used on the lock plate and hammer is something I learned from one of our members here, TOF. After seeing how nice it looked on several guns he built I asked him how it was done. It is not a true case hardening but does seem to impart some carbon into the steel.
The parts were hung on a wire and heated with a torch to cherry red, then dunked several times into a bucket of water with about 3/8" of ATF (automatic transmission fluid) floating on the top. I dipped the plate about four times, with about half second intervals between dips before leaving it in the water to cool. The quench water was about 70
o give or take. I also used the same process on the trigger plate and the rear sight.
Here is a quote from TOF that explains the theory better than I could by paraphrasing him, I hope he won't mind me posting it here:
"My theory is that most parts today are cast from metal that can be thru-hardened, so heating them and quenching will harden the part if plunged directly into water. However, if oil is floating on the water, it is picked up with each plunge and forms an insulating barrier as it enters the water. The carbon in the oil adds carbon to the part and also slows the rapidity of the quench. Instead of getting a part that is glass hard, you get one that is differentially hardened and requires no tempering. The added benefit is that you can manipulate the case colors on the part. A quench done at 50 degrees using 30w oil will give deep blue colors. As the quench temp is raised and the oil is thinned, you start to get lighter blues and grays on the metal. ATF contains components that increase its temperature stability, so it doesn't cling like motor oil and you get more of a solid color. It is also possible to get a French gray color under certain circumstances that require the color to be steel wooled off, leaving just a case hardened part."I experimented with a few different oils and quench temperatures and got the colors I liked the best from the ATF and 70
o quench. I would like to caution that small parts like triggers
can come out glass hard, depending on the alloy.
Use a
heavy wire or you might burn it in two with your torch, causing gravity to take total control over your red hot part. Yup, I did that once.
Curtis