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

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

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

I already knew the directions, but the bottle was in Spanish. That might be a challenge for some people. Other than that it is a great product if you carefully follow the directions.

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.

Great 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

Would have give 5 star but the directions on the bottle were in Spanish......I don't speak Spanish. Had to do an internet search to figure out how to use. Once I figured that out, it worked great.

Good product