I seem to be having a problem getting my rusted parts to completely convert to black oxide.

I have started doing some of the small parts on my Oberndorf Mauser. (buttplate, grip cap & rear swivel boat)

It is taking forever to get the entire part to turn black. I seem to have some stubborn places that do noy want to turn completely black.I am boiling the parts in a stainless steel pan on the stove.

Is it obsolutely necessary for every last bit of oxide to turn jet black?


Most of the part turns black, but some places still have a slight hint of a dark chocolate brown tinge.

I have been boiling the parts for nearly 3 hours this morning. this is the 2nd cycle. I am using well water that has been softened & then run through a reverse osmosis filter. It is about as close as one can get to distilled water.

Will it hurt to card off the parts as they are now?

how long are you letting it rust, is it scaly after the carding?

quote:

Originally posted by richj:
how long are you letting it rust, is it scaly after the carding?

I'm letting it rust about 16-20 hours in my greenhouse.

No scale, just some fuzzy areas like it says in the instructons. (before carding)

It's these areas that are just a bit fuzzier that are not wanting to convert as fast as the rest.

I have only carded once on the 1st double coat (as per the instructions) The parts looked great, a dark even medium dark gray.

Should I just go ahead & card the parts like they are?

The parts should turn black black almost instantly when immersed in the boiling water. 5-10 minutes is plenty of boil time. It will not hurt to card the areas that have not turned black. Card as usual, and apply another coat of the bluing agent. What blue solution are you using and how long are you letting it work? Are you using a damp box or open atomosphere? I use a damp box, 4-6 hours is usually plenty of rust time, any longer and pitting may result.

quote:

Originally posted by craigster:
The parts should turn black black almost instantly when immersed in the boiling water. 5-10 minutes is plenty of boil time. It will not hurt to card the areas that have not turned black. Card as usual, and apply another coat of the bluing agent. What blue solution are you using and how long are you letting it work? Are you using a damp box or open atomosphere? I use a damp box, 4-6 hours is usually plenty of rust time, any longer and pitting may result.

I'm using Brownell's Rust Blue.

I let it sit in a small 6'X 6' X 7' high plastic greenhouse overnight.

It takes a long time for the (brown) rust to appear. At 1st it just turns black sfter applying the solution.

Never used Brownell's, I either use Gun Goddess or Laurel Mtn. so I can comment on how it works. I have found that keeping the rust cabinet at 85-90 deg. and 85% humidity is about right for the solutions I use.

I went ahead & carded the parts.

The color is nice & even & it got a little darker after the 2nd carding.



How dark will this process make the metal after repeated applications?

So far, I am pleased W/the results.

Take a look at the metal parts on my Cadet in the Custom Rifles section. The metal on that rifle was blued/boiled/carded 6 times.

I think I have found the problem.

I carded off the 3rd application last night & I now have a nice, dark charcoal gray color.

It seems that I was applying a bit too much solution. That was resulting in an uneven rust coating.

On the 3rd application I applied the solution very spaingly, just enough to get a thin film that dried very quickly.

I allowed the parts to rust about 5 hours on the kitchen table. I ended up W/a nice thin, even rust coating.

I boiled the parts in fresh filtered water for about 20 minutes. The brown rust turned to black very quickly but I still had some brown in the checkering so I let it boil the extra time.

I never got all the brown in the bottom of the checkering to turn completely black but I carded the parts anyway.

The color change was dramatic! I think a few more rust/card cycles will give me the dark gray/black color I want.

Dear Wildcat Junkie:

I have a few suggestions.

First, I only use bottled distilled water when boiling the rusted parts.

Second, I use non-chlorinated brake cleaner to clean the parts thoroughly. Also, don't touch them parts with your un-gloved fingers!

Third, watch for any oil scum on the top of your boiling water bath after the first or second application. When the pores of the steel open up in the boiling water, they can release trapped oil. Its no big deal, just use a paper towel on the surface of your boiling water, and viola, its gone. Also, use a slow boil not a heavy boil. You'll save water, and bubbles don't attach to your parts.

Fourth, I have only used Mark Lee Rust Blue from Brownells. It works. I've done over twenty guns and numerous smaller items like Lyman 48 sights. 7-10 applications (with a 320-400 grit finish, 7 applications is dark grey and 10 is almost black), boiling water immersion and carding, then the sodium bicarbinate bath for an hour, and you are done in a morning.

Keep the relative humidity up in your house when you are doing it, don't run the A/C.

You're in upstate New York, right? So humidity is not an issue. Maybe in Arizona you might need a damp room.

Sincerely,

Chris Bemis

Wildcat Junkie,

I would second the requirement for distilled water.

And do not stop at 3 coats, it will look much better with a minimum of 6.

I use a humid cabinet because I want to control the temperature (80 to 90) and the humidity (90 %).

I let the first coat rust for a bit over 3 hours, checking it as it goes. Then the next can be an hour longer and so on. I rarely let them rust over 4 hours though. I boil for about 15 minutes.

I use Napa Super Clean or a product called Purple Power (I think they are the same formulation) for a degreaser. There is nothing better. You can dilute it with water but I use it full strenght. Don't get it on your hands or it will dry them out. You can get these at auto supply stores.

Two things:

First, if you don't want to pay for distilled water, get a rain barrel and collect and use rainwater.

Second, for degreaser a very inexpensive alternative is Arm & Hammer Washing Soda found in the laundry detergent aisle of grocery stores. Use 3/4 cup to 5 gallons of water and boil parts to degrease.

quote:

Originally posted by Toomany Tools:

Two things:

First, if you don't want to pay for distilled water, get a rain barrel and collect and use rainwater.

I have well water. That is 1st run through a strainer, then a charcoal filter and a watter softener before it gets to the house plumbing.

At the kitchen sink I have a reverse osmosis filter that removes virtually all the salts & inpurities. This has worked well for the small parts that are being done on top of the kitchen stove.

For the barreled action I will need a source for more volume to fill my large tank so I will probably look for a barrel to colect rainwater.

quote:

Originally posted by Toomany Tools:

Second, for degreaser a very inexpensive alternative is Arm & Hammer Washing Soda found in the laundry detergent aisle of grocery stores. Use 3/4 cup to 5 gallons of water and boil parts to degrease.

For the last few applications/cycles I have lightly scrubbing the parts W/comet & an old toothbrush followed by a thorough rinsing in very hot water prior to applications of rust blueing solution. that seems to make the solution spread & dry more evenly.

I am currently boiling the 10th application/cycle & will report on the finished product after I card nuetralize & oil the parts.

After the last coat has been carded I do a final boil in fresh water, remove the parts, dry, and oil them while still warm.

quote:

Originally posted by craigster:
After the last coat has been carded I do a final boil in fresh water, remove the parts, dry, and oil them while still warm.

I did my final boil in a weak baking soda solution followed by a (very) hot water rinse/dry.

I used a hair dryer to heat up the parts a bit more & then oiled them while still hot.

The parts (buttplate, gripcap & rear swivel base) look great.

I am planning on experimenting some more on the bolt body, bottom metal, shroud. etc before tackling the barreled action.

Post some pics when your done.