Rust blue question

[Topfmine]

I am restoring a P14 that has been parkerized but I want to refinish back in its original rust blue/ black finish. When I removed the fore sight I found the original finish under it rust blue finish, somebody couldn't be bothered to take it off when it was parked.
I thought I will give this rust blue process a go, so I tried it on two pieces from the rifle. I have been using Ammonium chloride or Sal ammoniac which seems to work well but gives a medium dark grey finish. While boiling after 3-4 processes, i noticed that some of the rust has not blackened, why is this is the piece over done or should I reduce my boil time as I progress. Any of the experts out there can assist.

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[bigduke6]

I cant see the "over" boil time time having any effect, can only guess something on the work peace or contaminated water ? I use just a solution of sal ammoniac and several boils, I did read somewhere regarding a P14 that it give a redish tint .......but don't know where or when I read it, possibly on this forum ?

[WarPig1976]

I found with Plinkertons? If the area didn't get velvety anymore it was done. Just keep going another few rounds and call it good.

[Topfmine]

The results on the two parts I done turned out very nice, so I done some more parts but it seems after the first boil for 20 minutes there was some areas on the parts that was still rusty and hadn't backed, so it's still a mystery, is this normal?

[WarPig1976]

Yes, everything you describe is normal.

[no4mk1t]

When I rust blued my Krag, I did the smaller parts first to get the process down before doing the larger parts. The butt plate pictured went through 8 rust/boil cycles. The receiver went through 6 because I couldn't tell any difference after 6. Both came out great.

Rust after boiling. The velvet look is easier to capture in a photo after boiling.


After carding.


Receiver after oiling and reassembly.

[Topfmine]

That's exactly what I am getting, such a beautiful finish I wondered why I hadn't done it before. When I done my last card before oiling I thought that the finish was not dark enough but the oil treatment brings out the richness of the dark finish.

[WarPig1976]

Rust blue is the way to go for the hobbyist for sure.
Some pics when your done....

[no4mk1t]

If that's what you're getting Top, I'd say you're doing it right.
And as WarPig says, pics when you're done.

[no4mk1t]

Rust blue is more matte than hot caustic blue because you are only polishing to a 320 finish to give the rust blue solution some bite. Polishing to a 600 finish does not work well with rust blue according to what I've read. I have not tried it myself.
Nevertheless, it has a classic elegance that is lacking in modern hot caustic blue.