Better Than Biscuits and Mustard

What do you do when you have a small steel part you want to blue? You get out your Birchwood-Casey Super Blue and paint it up, right?

That’s what I used to do. Today I decided to try oil-bluing for the first time.

What is oil bluing? Funny you should ask. It’s an old, simple way to blue and even case-harden parts. If your part is hardenable steel, oil-bluing may harden it all the way through, because it’s basically the same thing as heating and quenching. If you harden a part that shouldn’t be hard, you’ll have to anneal it later.

I modified my friend Mike’s Marlin Model 60 stock to accept a real sling stud, not one of those stupid things that clamp to the barrel. In order to make the modification work, I had to grind a dome nut down to about 0.180″ thick. In this case, a dome nut is a little nut that goes inside a gun stock. The stud’s screw goes through it. There is very little room inside the Model 60 for a nut, so you have to make your nut smaller in order for it to fit. You also have to use a 3/8″ Forstner bit to drill out a cavity inside your stock, and it has to be deep enough for the nut to rest in it without protruding.

Grinding the nut took the bluing off one side, and I wanted to replace it, even though the nut would be hidden.

I found some Kubota conventional motor oil in the workshop. I would never use this stuff because I like synthetic. I poured some in a soup bowl and put it on my kitchen counter. It’s great to be single. I took a little wire and ran it through the nut so I could use the wire to hold it. I heated the nut until it was red hot. I dropped the hot nut into the oil, and I was done.

The nut is blued, I didn’t have to buy Super Blue, and the job is finished.

Buffing it would have made it even better. I don’t want the buffer throwing hard-to-find nuts all over the workshop, however.

Incidentally, if you want to do this modification to your Model 60, here’s how you find out if your nut and screw clear the magazine tube, which will sit on top of the cavity the nut sits in. You use an ohmmeter. If the screw or nut touches the magazine, the resistance between the screw or nut and the magazine will be nearly zero. If not, it will be infinite. If it’s not infinite, make the hole deeper or grind the metal parts until you get zero.

You’re welcome.

The gun is much improved now. Mike owes me.

Today I read that a product called Nu-Blue, from Stockdoc.com, looks and protects better than the other quick bluing products. Don’t know if it’s true. Some guy tested a bunch of products.