Brownell Formula 44/40 Instant Gun Blue

It works and for being from Brownells the price wasnt bad

This stuff reacts instantly and is very forgiving. I use alcohol or mineral spirits to prep metal surfaces on my blacksmithing projects and get great results from this. You don’t have to do multiple coats either to get good finishes. 1 bottle lasts a while and be sure to change your application instrument (swab or cotton ball) after each use or you can contaminate the fluid.

As the listing states, the product blues(black) almost instantly. Works really well. My only complaint is that it never gets truly black. More of a dark gray color. I used it to reblue a vintage airgun that was rusted. It came out like new. Just with it was a bit darker.

from what i had seen online from ppl using stuff like this, not this very brand just a solution to black metal, had trouble getting the parts to come out all the same, one would be covered an the next would be blotchy so i didnt know what to expect. when i cut the foil seal off the tip of my blade was blade when i pulled it back so i knew it worked but didnt see how well it worked til i brushed a little onto a toe clamp i had made an it really was instant an didnt take near as much as i expected. i didnt want to dunk the hole part in the solution so i was just brushing it on an this will be the method i use from now on unless i run across a large part or something but this stuff works really well an if ur looking to black some metal parts this works. buying it in small 2oz bottles is probably not the best way if u have alot of parts or large parts but i will be sticking with this brand.

I was pleased to see that this product actually did what it is advertised to do. It matches quite nicely.

A good buy

I bought this after getting a shotgun which was marred by rust which destroyed the finish. Just horribly maintained. The barrel wasn't rusted through, mind you, but it had penetrated deep enough that once the rust was removed, patches of the finish were nonexistent. I bought Brownell Formula 44/40 as a fairly cheap method of restoring a good look to the shotgun. What did I really have to lose? less than $13.00 isn't a lot of money, after all. All it took was applying it to a patch, and running it along the affected areas, and the blackness lost to the rust was restored. It's not absolutely perfect, of course, but close enough that anyone who isn't looking for a difference won't notice. And I imagine applying more of it would darken it further, but what has already been done has satisfied me.

Works exactly as advertised. I used the cold blue to touch up sharpening errors I had made on two former USMC Mk2 "KA-BAR" knives (a Conetta and an M.S.I. with 1095 steel blades). Instantly blued to a finish very similar to the existing Parkerizing on the blades and allowed me to resharpen to achieve a sharp edge with about 1mm of shiny, sharpened edge showing...just like the factory did it all those years ago. Best cold blue I have found.