I have a question about this stuff:

32 oz. : OXPHO-BLUE® | Brownells


Say you have a gash or scratch in a blued gun and touch it up with Oxpho Blue. What happens if you get some of the chemical on the intact blue finish? Will it affect it at all?


Thanks, SandSpider

It can discolor it a little, make it dull looking if you aren't careful in wiping it off when you are "rubbing it in"

If you search around brownells site there are some tips on using it. Heat the metal some and using the "shoe shine" method with a soft cotton cloth worked best for me.

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Straight shootin'
SWCA#2439

In the past nearly 60 years I have used virtually every cold blue product available. The absolutely best results I have ever had have been with the Oxpho Blue Gel, not the liquid. I have used both and the gel is far better.

As Dusty3030 stated cold blues will damage the existing bluing to some degree. You can't simply spread them everywhere but have to be careful to only use them on the area you need to color.

There is another product that has been highly recommended on the forum. As I recall it is called "New Blue", I believe, and is apparently only available on-line. I can't find it now, I probably have the name incorrect.

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Gunsmithing since 1961

I believe that product name would be Stock Doc Nu-Blue...

The two BEST cold blues I have found over many years have been the Oxpho paste AND the Birchwood Casey Perma-blue paste. The other thing that I find is that some guns work better with one or the other. I suppose some of the steels are treated differently and take one better than the other. Since they are so inexpensive, I'd seriously try BOTH and see which one works better on a particular job you are doing. IMHO both are about the best cold blues but one usually works better than the other for an individual gun.

Chief38 is correct. Some of the metals take bluing differently than others. Some of the new so-called metals can't be hot blued. The best solution is to try a small amount somewhere you can't see to see if it takes.
I use Oxpho bluing from Brownells and it is one of the best cold bluing products. But it doesn't compare to the longer lasting qualities of hot bluing or rust bluing. For touch up it works great. If you get it on the old bluing just use bronze wool to buff it up.

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Tom
NRA Pistol Inst

Just curious. Have you tried the Stock Doc Nu-Blue mentioned above? I've never tried the OxPho paste but the liquid is pretty good. I have tried the Permablue paste, and it's pretty good too. I'm just wondering if the Nu-Blue is as good as what I've read....

The only other cold bluing I've tried other than Oxpho and Perma-blue is a liquid called 44-40. The 44-40 gave a nice color match but gave me no longevity at all so I tossed it years ago. The reason I am not too fond of the liquids and always go to the paste is because the liquid tends to travel and hit areas that I do NOT want it on. The 44-40 also tended to react with the good blue on the gun and made it a weird color. The Oxpho and Perma seem to have no real discoloring effects on the good bluing and wipes off pretty easily from areas not intended for treating. It also stays where you apply it much better.

I use oxpho blue for small touch ups like the ends of pins or bottom of screw slots that may get brightened up during installation. Other than that, I don't depend on a cold blue to do much.
They usually end up expanding a small area you're trying to fix into a large area you now need to fix.

Oxpho blue does have the big plus in that it does not after rust. Many of the other cold blues do including 44-40 that has been around for years.
I think Numrich sells 44-40 now. It does work (blues) pretty well. But will stain some surrounding blue too.
It will rust and cause extensive pitting if not flushed from the surface with warm water after application. A bit of soap helps too.
I've had more than a few guns brought in that were lovingly 'reblued' with the stuff and then packed away in storage.
When next looked at, the gun case was stuck to the gun with the rust in between. I think it's the stannic acid(?) compound in the stuff and others that causes the rust.

Cold blued guns have a distinctive smell to the metal too,,at least the ones with the corrosive agent(s) in them.
Oxpho blue doesn't seem to have that odor to it.
I've never tried the newer "Nu Blue' or any of the other cold blues out there. A couple of gun show dealers I know swear by Nu Blue. That should tell you it might work pretty good.

I rust blue even small parts that need to be blued.
For me,,Cold Blue is for scratches in the bottom of the screw slot after re-assembly.