Over the weekend I finally got to a project I have been wanting to try for awhile now but just haven't had the time and that is hot bluing. I would like to some day be able to do high gloss hot bluing and that's what I was going for but my level of polish needs to be a lot higher as it turned out more of a semi gloss.
Here is the pic of the mag before anything was done. Note next to the number 5 there is a grey mark, I had some sulfuric acid on my hands and just happened to grab my mag and that's what happened about 1 year ago. Other than that there is just some normal wear and tear on the mag.
Now for the prep work, I did this all by hand with different levels of sand paper and no polish and that's where the glossiness comes from. I started with 180 and worked up to 3000grit paper but there are scratch marks that I didn't get out and by the end of all the hand sanding I didn't care. I think I need a sand blaster and some polish wheels for my bend grinder before I do this again.
Here a pic after the prep work.
Now I cleaned the parts with acetone and set them aside. Next I went out to the grill and heated up the pot of 5 lbs potassium nitrate(kno3). Believe it or not I had 3 lbs just laying around from past experiments but I wanted a little more so I went to the local farm and fleet and got the closest thing they had. Gorgons Stump remover is 99% kno3 so I bought 2 pounds of that and threw it in the pot.
After about an hour the KNO3 turned from white powder to black ash and finally into a yellow liquid. At this point I hung the parts from some copper wires and submerged them for 30 mins. After they were done I removed them and put them in a bath of motor oil over night.
The next morning they appeared to have a white crust on them in some spots but it was just cooled kno3 and came off with a little water.
Here is the pic of the finished Mag.
Overall it was a fun project and tho it doesn't have the shine I wanted I'm still happy with the results.