Rust blue advice needed

Hi All,
I'm trying to rust blue a barrel with Mark Lee's Slow Rust Blue #3. I've followed the directions to a T and all I get is a powdery black coating that cards back to a light gray and powdery black.
What am I missing? Barrel was flat filed and sanded down with final grit being 320t. De-greased with acetone and washed with Simple Green and Dawn. Sweat box is running at 90* with 50-60% humidity. Rust completely coats treated surfaces in about two hours. I've taken the barrel back to bare metal and started over and have gotten the same results. De-greased 0000 steel wool cards the second and even the third treatment back to gray metal in several spots and all sharp edges; the rest of the surface is a chalky black. The areas that go immediately back to gray metal when carding have been repeatedly de-greased and sanded with no improvement. Oh, and the solution goes on smooth and flat with no beading so I don't think grease/oil contamination is the issue.

Any suggestions?

Thanks!
John

Hopefully someone else can help you with the Mark Lee's Slow Rust Blue but if they can't you could always brown the barrel using Mountain Laurel's browning solution and then either apply steam or boiling the part in distilled water to convert the brown ferrous oxide to black ferro-ferric oxide.

It might take a while but if you have an old fashioned tea kettle, holding the browned metal over the kettles vent will blow steam on it to make the conversion.

Had I thought of it at the time, that's what I should have done with my CVA 12 guage double barrel. Instead, I used a large pan of boiling distilled water on my old Coleman stove to do the conversion. Because the barrel wouldn't fit into the pan I ended up using a clean paint brush to repeatedly slosh the water onto the barrel. Talk about a pain but, it did work !

Do you need to add water to your sweat box? If so, use distilled water.

Mark Lees is a good rust blue. I’ve rust blued a lot of guns with it after year using the Swiss federal Armory formula from the angier book. Lee’s works best for me at very high humidity. I live in FL and have it naturally so didn’t need a sweat box. Often 90+% humidity. Rusting was always within 30 minutes.

Thanks for the suggestions. I've discovered I was trying to rush the rusting process and not carding sufficiently. I've stripped the barrel back to bare metal and have started over. Through experimentation I finished the barrel with 400 grit. It gives a finer rust which cards easier but it appears I will have to use more applications to achieve the desired color.

Thanks again.

jm190 said:

Thanks for the suggestions. I've discovered I was trying to rush the rusting process and not carding sufficiently. I've stripped the barrel back to bare metal and have started over. Through experimentation I finished the barrel with 400 grit. It gives a finer rust which cards easier but it appears I will have to use more applications to achieve the desired color.

Thanks again.

Click to expand...

Some times over, and over, and over, I try to pick rainy days to brown a barrel, This is going to sound out of place, but one of the best browning solutions I have found is urine, I know, I know, hold on and think what the old timers used. Once you get the oxidation stopped I have found it to be acceptable. Didn't have the fancy stuff in days gone by, especially out in the bush.