Cold bluing turns rusty brown

[8thArmy]

Hi all,
Lately I've tried to cold blue my real sword and the result turned out to be well, but when I tried to blue the upper reciever it went disastrous, I sanded the old blue off fully washed it and applied new gel on with swabs, it looked good at the beginning hut after drying it almost immediately turned into a rusty brownish color, anyone know why is it like that?

[CDN_Stalker]

Probably something to do with the quality of the steel. Bluing is a form of oxidization, and you'll get various colours of blue to rust depending on the metal content. I just blued a pair of knife blades, high carbon O1, the colour literally is a dark blue colour. Have also blued aluminum in the past and it's come out black, sometimes other types come out crappy brown. If you wipe the finish with oil, does it stay crappy?

[KNIVEZS]

same thing happened to my old cyma AK
that cold bluing solution turns steel into a rusty brown color
top cover is made out of steel and the lower receiver is pot metal

thenooblord's pic

[8thArmy]

Im bait confused since the first time I blued it it turned nice deep blue and that time I didn't even do a proper sand down preparation. This time, same part, with degrease and blue/rust removal treatment before bluing, it turned out brown, it seems like it rusted right after blued, maybe I missed an important step before applying the blue?

[8thArmy]

Originally Posted by KNIVEZS

same thing happened to my old cyma AK
that cold bluing solution turns steel into a rusty brown color
top cover is made out of steel and the lower receiver is pot metal

thenooblord's pic

Mine looks like the same as yours.

[m102404]

Depends on the make up of the metal (impurities/etc..)

But you've also got to stop/arrest the blueing process after you apply it. Distilled water (IIRC) stops/slows the reaction so you can clean/dry it off. I've applied oiled as well.

IIRC a blueing solution are basically salts...you've got to get them off of the metal or they'll continue to react with the moisture in the air.

Midway USA have youtube videos about applying cold blue solutions.

[L473ncy]

Originally Posted by CDN_Stalker

... Have also blued aluminum in the past...

You can blue aluminum???? I always understood it as a process of reacting the ferrous atoms in a ferrous alloy (ie. steel). Or is it a different process that is also known as bluing but not "true" bluing.

Secondly.... I like the "wear" on that AK. Seriously it actually looks like it's been naturally weathered. I assume the solution was applied via "drybrushing" or "highlighting" raised parts? Or was it totally a mistake (which is how knivez explains it....)?

[m102404]

Some aluminum will blue...most times it goes more black than "blue".

Brass Pro and other gunshops carry Cold Blue and Aluminum Black

....best to do a test spot somewhere discreet to see how it'll react.

....sometimes, where cold blue solution will not seem to have effect on AEG parts, Aluminum Black may be more effective.

A little goes a long long way...my last bottles of the stuff lasted for years. Keep sealed, apply sparringly. Always use a fresh applicator (i.e. qtip/bit of cloth) if you don't want to contaminate your bottle. If the salts precipitate out of solution...it's obviously going to be weaker and less effective.

[8thArmy]

Just weird that the first time I sanded it down not so completely nor I cleaned it througly, but the blue worked like a charm, this time I followed all the preparation procedures and it rusted brown right after dry up.

[Forever_kaos]

A friends Classic Army MP5K I tried to blue for him turned out how you are describing:

That was a few minutes after applying, stunk of rotting eggs to boot.

Where as my Cyma AK's that I blue, turn out much better.

Usually steel wool and a good coating of gun oil remedies some blemishes in the finish I find.

[8thArmy]

Originally Posted by Forever_kaos

A friends Classic Army MP5K I tried to blue for him turned out how you are describing:

That was a few minutes after applying, stunk of rotting eggs to boot.

Where as my Cyma AK's that I blue, turn out much better.

Usually steel wool and a good coating of gun oil remedies some blemishes in the finish I find.

Wow now that's bad! Mine actually turned out to be shinny and smooth, just rusty color, almost look like browning

[disasterarea]

Originally Posted by KNIVEZS

same thing happened to my old cyma AK
that cold bluing solution turns steel into a rusty brown color
top cover is made out of steel and the lower receiver is pot metal

thenooblord's pic

I don't know why, but I love the look of that thing. Reminds me of some Middle-Eastern AK's I've seen. Would fit right in somewhere around the Khyber Pass.

[8thArmy]

tried again, sand down, washed cleaned, blued....still rusty brownish

[redzaku]

well look at the bright side, you have gun that has been tested against mother nature and won...

[Andres]

It looks better anyway...