Cold blue. Not worth my while.

zedex

zedex

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I have done the cold blue method on my 7 mag with lackluster results. The blue stays for a bit but wears very fast. What do they use at the factory for bluing? I would assume some type of heat application. Are there any good alternatives to cold bluing that last a long time?
Thanks
 
Some guys on here (I think) are set up for hot blueing (you're right, heat application using salts). Some use other methods such as oxidizing. CamK posted a pic on this forum of an 870 that he used black oxide on - it was sweet.
 
I use the lye and fertilizer method (hot blackening process) with reasonable success on smaller items. Rust blue is time consuming, lots of polishing initially, humidity box time and carding, repeat 5 to 6 times, leaves a beautifully deep blue black finish. The factory uses a hot blue process of salts heated until molten at about 600'F they also contain some manganese which gives the blue.
 
zedex said:
I have done the cold blue method on my 7 mag with lackluster results. The blue stays for a bit but wears very fast. What do they use at the factory for bluing? I would assume some type of heat application. Are there any good alternatives to cold bluing that last a long time?
Thanks
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Usually nothing available for the quick do it your selfer at home that will work well.

A hot blueing process will give you the results your want. It shouldn't cost more than a couple thousand dollars to buy what you need..... of course you then have to learn what to do.....

Most gunsmiths can blue it for you at a reasonable charge.
 
BigUglyMan said:
IIRC Rick Timmins at ATR has hot bluing tanks.
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Yes I do and as a matter fact was blueing today.
There are some commercial cold blues that work ok but nothing replaces good old hot blue, it lasts well and looks good.

Death Junky I think 500 degrees is a little TOO hot most salt baths are run just under 300 degrees F
 
There are some cold blues like Oxphoblue which can do a reasonable job. Commercial hot bluing uses a caustic/nitrate bath at close to 300 degrees F. The heat is for the chemical process, and by itself is not hot enough to colour the steel. There are heat bluing processes in which heat causes the colour change, but the amount of heat can affect heat treatment, so it is only useful for some parts. There are rust blues which use boiling water and/or controlled humidity boxes. There is a process of oil blackening, involving heating the part, oiling it and allowing the oil to flash off and burn. There are others. Many of the cold blues available do only mediocre job of bluing large surfaces, like an entire gun. The rust blues can be done in a home shop. Phosphate finishes akin to parkerizing can be done easily at home. Hot caustic bluing requires a more elaborate setup, and not too many home hobbyists would want to get set up. There are also the bake on coatings. With most processes, surface preparation is a major factor in the quality of the results.
 
alberta tactical rifle said:
Yes I do and as a matter fact was blueing today.
There are some commercial cold blues that work ok but nothing replaces good old hot blue, it lasts well and looks good.

Death Junky I think 500 degrees is a little TOO hot most salt baths are run just under 300 degrees F
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ATR

Do you have a web page or the like? I'd really like to see some more of your work.
 
Try express rust blue. Very hard finish. Can be done at home. No need for humidity boxes. Still LOTS of elbow grease is required for a good finish. Taken from http://www.pjsproducts.com/
"Rust Blue - this EXPRESS bluing compound gives a beautiful black-blue durable finish and gives you the option of how light or dark you want the end result. The process is similar to that used centuries ago but an express agent has been added to streamline the bluing operation. The steel is heated by water or torch. This bluing approach is the most desirable choice for double-barrelled guns to avoid weakening the solder. 8 oz. - $25.00"

I've seen his samples done with a heat gun between coats of rust bluing and carding with steel wool. The finish is way superior to that of any cold blue.
 
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Hi Guys,
When I use cold blue, after polishing the metal, I precondition the piece by spraying it with spray -on oven cleaner.
After 15 minutes or so I wash the piece off with boiling water, blot the excess water off with a tissue and apply the cold blue while the metal is still hot with a cotton swab. Don't touch the metal anywhere with your hands.
The blue goes on evenly and the finish is a nice deep blue or black.
When you have finished , re wash with boiling water again or else it will tend to rust. Apply WD40 and let sit for a while. After this, I clean off the oil and buff the piece lightly to bring up the luster in the finish and apply oil again. Some people recommend linseed oil.
Check again daily for about a week to ensure that rust hasn't started to form any where.
The cold blue I have found to be good when used this way is made by Gunslick.
Never the less, cold blue tends to wear a lot faster than other hot blue methods
Jim
 
I've done just about the same as Jim. Using Gunslick blue from Wally world.

Careful prep (fine steel wool, brake cleaner), heat the parts with a hairdryer as hot as I can get them, apply blue with swab, sit three minutes, rinse, repeat twice more (steel wool/hairdryer/blue/rinse) then another steel wool buff then a good slathering of regular gun oil.

I did an old mauser up like this, and all the parts came out looking very impressive with a nice even deep blue, including the larger bits, barrel/receiver, etc.
 
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