I am about to start the 4th coat of rust blue solution on a Pre Garcia Sako .243 that I spent the better part of the winter polishing (it was someone's 'truck gun')...

I am using Mark Lee #3 Slow Rust Blue which I believe is a nitric acid/nitrosyl chloride blend- it's kind of day glo green yellow. No damp box- just rusting in free air in my den which should be temp and humidity controlled like the rest of the house. I've done this before with very presentable results.

Anyway, I already have the excellent rich blue black color after three coats. However, the receiver is etching deeper than the barrel and spots on the underside of the barrel are also etching deeper.

My question is: Will the etch even out with subsequent coats of solution? Or Stop now and repolish for the rest of the Spring.

Is there any way to even out the etch?

Your experiences and advice appreciated...

DeeBee---

It's unusual for a receiver to etch deeper than a barrell! I've got to get some of that stuff!

I pit is a pit is a pit and that's what the rust blue etch is. The secret of a really fine finish is to have all the pits the same size.

I suspect you're waiting too long before boiling and carding. My 41 Mag has some irregular pitting from the blue for that reason. (I had the clock set for 3am to boil and card and didn't.)
I just shipped off a new Jeffery 500 that looked to have been coated with solution and then forgotten a week. It was deeply pocked, but the color was good.



I found a picture of it.

It will even out somewhat with further coats, but once the steel is gone there's not much to do but blend in or remove and start over.

I took your suggestion about the wire wheel work hardening the steel and counteracted this by allowing more time with the solution on- this was for the small parts only- it worked, the potmetal trigger guard, floorplate, bolt, bolt shroud and screws are stunning! Very satin deep blue black almost iridescent in the sunlight.

Parts of the receiver and the barrel cylinder are now what I consider 'frosted' the remainder being the lovely satin. I have made one change from the .22 I did for a friend last month and that was to use a natural sponge instead of a Qtip swab- I think the sponge is holding too much solution...

I'm going for the next coat tonight hoping I can achieve some degree of blending. I may skip the receiver and barrel cylinder and see if I can get the rest of the barrel to 'catch up'... If not, someone's going to have to bead blast the thing cause that rust don't come off easy...