Yellow color on metal parts test --- it worked!!!

[Heinz]

You may find that strawing is significantly more difficult than you think. It is easy to straw one part, more difficult to straw two to the same color, lots more difficult to do a whole Luger's worth. And then, you want it to hold that color for a couple of dozen years. Also, you do not want to adversely effect the heat treatment of the part. That certainly should not happen at 350, but 500 can be another story. Have fun, do not be too impressed with your first pass. Start with scrap.