View Full Version : Heat Tempering question from a big dummy
09-03-2009, 01:33 PM
Do to my stupidity and late night working on this I have a hammer from a 1892 Lebel Pistol that in the process of removing some rust I bead blasted the straw yellow color right out of it.:mad:(should have used steel wool, I know) I'm sure the yellow color was part of the tempering process after they hardened the steel. Anyway I would like to bring that straw yellow color back. Do I need to harden the metal again, quench in oil, cool then temper to a yellow color or can I re-temper the yellow color back to it w/o re hardening. Straw yellow is at about 440-450 degrees so I could temper it in a oven or just use a torch like with everything else.
09-03-2009, 07:09 PM
Straw yellow is rather hard for a hammer. Used more for hard knives. Gun hammers were often cyanide case hardened. Typically, old hammers were in the blue range used for chisels and punches.
In any case if you want the color back: Polish it to a smooth bright finish. Get all oil, dirt, and fingerprints off with a solvent like brake cleaner. Slowly heat it in a clean SOFT alcohol or gas flame (rapidly and smoothly moving it in and out of the flame) so that you can watch for the color changes caused by the iron being oxidized by the oxygen in the atmosphere outside of the flame. As you get to the color you want get away from the open flame and spray it with WD-40 to stop further oxidation, or dip it in oil. Practice with a piece of scrap metal until you become proficient in heating and timing.
09-03-2009, 11:25 PM
This was the neatest thing I have done in a long time. It was like magic. Something that was polished to a chrome finish turned to gold wright before my eyes. The hammer was a little tougher since the spur is thinner it wanted to turn purple. I'm sure with a little more practice it will come easier but for a first time I was elated and it turned out better than what I started with.
Here are some before and afters.
The before of the trigger is the face, the after is the back b/c it showed the color much better.
09-04-2009, 07:28 AM
Nice job. I have been using the "Slipshod Tool & Die" method of tempering for 50 years, and still do not have it mastered.
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