Hot Vs Cold Bluing Questions

[twofewscrews]

Hi,

I recently installed a slide action tube on my Maverick 88 because the plastic and metal pinned one seemed iffy in cold weather. After racking the firearm to ensure the firearm worked as it should I noticed that some of the bluing on the magazine tube is coming off. This isn't a major concern as its primary role is home defense and thus, I'm not too worried about rust, but this did peek my interest in bluing. If I do end up re-bluing the magazine tube I'll most likely go the cold route as hot bluing seems to be a much more space (which I don't have) and time (which I also do not have) intensive project. That being said I have a couple of general questions about bluing.

First, I've been told hot bluing is better then cold bluing, is this true? and if so, why?

Second, I understand that if one applied cold bluing to a firearm that was hot blued, the cold bluing will generally be evident, but does this matter? IE it may look funny, but it will still protect the firearm, right?

 

[Jim Watson]

No form of blue will stand being rubbed by the pump. Just as well give it a wipe with an oily cloth every once in a while. Or maybe auto wax.

 

[AK Hunter]

Yes anywhere that something constantly rubs on the blued surface will cause the bluing to be rubbed off. Like on the selector of this PSL receiver. It's only cycled about three times.

 

[starling]

If rust is your worry check out a product called Eezox. If you decide to cold blue save yourself some time and effort and get Oxphoblue from brownells. Anything else basically turns brown from after rust. Oxpho doesnt and its easy to touch up.

If it rubbed off hot blueing though it will rubb off any cold blue. Hard chrome might handle it depending on whats doing the rubbing.

 

[BBBBill]

Bluing provides almost no rust protection. A little, but very little. Even the best which is rust bluing. Conventional hot bluing is next and cold bluing, which is realy just a chemical stain even less. Keep it oile or waxed.

 

[jmorris]

There is more than one product out there for cold bluing, some of them actually promote rust. Or to put that another way, bare metal won’t rust as bad as it would if you applied the product to it.

 

[twofewscrews]

Bluing provides almost no rust protection. A little, but very little. Even the best which is rust bluing. Conventional hot bluing is next and cold bluing, which is realy just a chemical stain even less. Keep it oile or waxed.

So then, would I be correct in thinking that bluing more of a finish then a rust inhibitor?

 

[Steve in Allentown]

So then, would I be correct in thinking that bluing more of a finish then a rust inhibitor?

Yes.

FWIW, I've been using Blue Wonder with excellent results. But like any bluing it needs to be oiled to keep the rust away. I use Eezox oil on all external surfaces for rust prevention.

Here's an example of what it looks like.

Before


After

 

[grter]

Blueing is a rust turned into oxide (blue black) coating that does protect against damaging corrosive red rust. It's certainly not the best protection but it is much better than bare steel and has been used and proven for at least hundreds of years if not more. You still need to oil the metal and keep it out of rust prone environments but bluing does work.

The hot blueing method is a relatively modern way of forming an oxide finish on the surface and produces a quality bluing finish. It does require the use of some nasty chemicals along with safety precautions to do.

The other old method of blueing was to allow the metal to rust but no so much that pits form then boil it for about and hour buff and polish then repeat the whole process over and over until you get the desired finish. When done with that part soak it in kerosene of other water displacer dry and finally oil. People say this semi matt finish is the most durable.

Cold bluing is not real blueing from what I read. I read it is some sort of very thin fragile blue/black copper like coating that does not last and rubs off easily. It might be good for touch ups.