Aluma Black by Birchwood Technologies - Cold Brush on Blackening Solution for Aluminum alloys Traditional Patina Blue and Black Oxide Touch-up (1 Gallon)

When I opened and saw a light blue liquid, I thought I had the wrong stuff but it turned black right away!!!!!

Does what it’s supposed to but it’s not a complete system. Be sure to read the instructions on the manufacturers website. You need a surface sealer. You cannot get a durable black coating from this product alone. The finish rubs off easily. I wish it were sold as a package with an appropriate sealant.

Couldn’t get it to work

Works very well

I liked the packaging. I used it to anodized some aluminum.

I picked this up to try on some aluminum hardware and touch-up projects. I’ve also been considering a few aluminum craft projects, so I figured this would be useful to have around. The first thing I learned is that surface prep really matters with this stuff. A lot of aluminum pieces have some kind of clear coating on them, and this solution won’t do much until that coating is removed. I had to sand the surfaces first before applying it. Once the surface was cleaned up a bit, the solution worked well. I tested it on a large aluminum nail, and the reaction started almost immediately. You can actually see the solution bubbling while it works, and the black finish started developing in well under a minute. I also noticed this works much better as a dip instead of brushing it on. The finish came out more even that way, and the process was quicker too. Using a brush still works if you want more of a distressed or uneven look, but dipping gave me the best results for what I was trying to do. One thing worth mentioning is safety. I made sure to wear gloves while handling it because the solution can irritate your skin. I’d also recommend using it in a ventilated area. After the finish develops, sealing it with a clear coat or another protectant seems like a good idea if you want the finish to last longer. My only real complaint is the label on the bottle. The print is extremely small and difficult to read. I had trouble making out some of the instructions . Overall, this works well for what I need. The results from my test were fast, the finish looks good. It seems like a solid option for touch-ups, hardware, or small projects as long as you take the time to prep the surface properly.

Nasty nasty stuff. I'm surprised it's legal for consumers to buy. Do not use unless you have quality protective gear, and definitely do not use indoors.

It works well and it works fast. Like, really fast. I dunked the end of an aluminum antenna for less than 3 seconds and you could see the color changing in less than 10 seconds. By the 30 second mark the parts were already a solid dark gray, and again that was with barely any exposure time. If your goal is to turn aluminum black, this absolutely gets the job done! That said, it's not all sunshine and rainbows. The biggest issue is the cap. While it feels like a normal child resistant lid, but in reality it comes off far too easily. Heck, when mine arrived the cap had already popped off during shipping! If it weren't for the inner foil seal, the entire bottle would have leaked. The manufacturer really needs to invest in better sealing caps... or at least ship it in a sealed bag or with tamper tape like most other liquids. I have mixed feelings on how easy to use it is or not. That's bc my other gripe is the label. The directions and warnings are printed in what I swear is a size 2 font. Seriously, I'm mildly ashamed to admit I had to take a photo with my phone just to read it. I am attaching those photos here so at least others do not have to play the same game. One final note, if you want the finish to truly last, you should plan on sealing it afterward with a clear coat or other protective finish. On its own, it works, but sealing makes a noticeable difference in durability. At $26 for an 8 ounce bottle, the value is fair. Not amazing, but not unreasonable either. If you have aluminum parts and you want them black it's not like there are that many options shy painting or powder-coating. While it may not seem like much, when you properly dilute it will cover parts very well! Pros: -Works extremely fast -Very effective at darkening aluminum -Minimal exposure time required -Clear and consistent results Cons: -The cap is poorly designed and unreliable -Label text is absurdly small -Should be sealed after use for best longevity Effective, fast, and does exactly what it claims. Fix the packaging and it would be even better.