Birchwood CaseyFast-Acting Long-Lasting Spanish Perma Blue Liquid Gun Blue for Steel, Touch-Up & Complete Reblue, 3 FL OZ (90ml)

Great product!

This is a replacement for the bottle I just used up. Does a great job

The blue chemical works well . I use an electric heat gun to heat the metal and that works great.

Good product, five stars there. But this item had instructions only in Spanish. I had to look it up on the internet.

I used this on my Glock 19 for some surface scuffs that I caused by putting on new sights. I used a Vism rear sight tool and I did not adjust it quite right and it slightly drug the rear chuck across the slide. It caused a few minor scuffs or dings about a half inch long. I was going to use the Birchwood Casey flat black touch up marker like others have said worked, but after I got it I decided heck no. It would have looked terrible.So I thought what the hey, I would try it with the perma blue and try one small spot. IT WORKS. I end up doing the rest of the marks and now you cannot even tell they were there. It was just deep enough that I could see metal and it was driving me crazy. I even tried Hoppes no 9 first, just to make sure it wasn't surface transferI did some searching on the best way to do this. I heated up the slide with a heat gun to get it warm. Apparently it works better if the metal is warm. If you get it too hot, it will stink when the perma blue hits the hot metal, but still worked, I just kept applying until it got dark enough and then rinsed it with water to stop the reaction. When done, I wiped it down with gun oil and buffed it with the cloth.I also did my dad's Vietnam bayonet and it turned out awesome. I was trying to sharpen it years ago and it just left a lot of scuffing. I heated the knife, added the perma blue until it started to get dark and then rinsed it. I did this 4 times and then I followed up with 0000 steel wool and some gun oil to smooth out the perma blue and BAM, it looks awesome again. Took care of all the little scratches using the 0000 steel wool too.I normally don't get real excited about items, but this one I did. I fix 2 issues with one product. And it did what I would expect it to do.

Good product

This stuff has been around forever, it works exactly as it should, but you absolutely have to be extremely careful and make sure all your metal parts are as clean as can be! Scrub scrub scrub with your favorite cleaner, runs with water, and give it the wipe down of your life with some mineral spirits or Isopropyl alcohol in water! I use it on all the action parts, but the barrel did not take because it was not clean enough

It's possible that I didn't understand the purpose of gun bluing liquid. I thought it was supposed to create a thin rust-resistant layer by converting red iron oxide into black iron oxide resulting in a bluish-black protective finish. This product, Birchwood Casey Fast-Acting Long-Lasting Spanish Perma Blue Liquid Gun Blue..., turned the antique horseshoe to which it was applied an unattractive rust color. This was not the result I desired. When I saw what was happening, I turned the horseshoe over and applied the liquid to only the left side. As a result, the left side immediately rusted. The right side shows the original condition of the metal. I did read on the internet that leaving the liquid on the metal too long could cause it to rust. But in my case, the metal rusted rapidly and never darkened. I may be a bumbler. In fact, nothing could be more likely. But in this case, I'm pretty sure it is the product that caused the metal to rust.