Homebrew Anodizing

[rtracy2001]

Anyone here ever anodized aluminum at home? I just finished machining my 80% lower and I am weighing options to apply some sort of finish. So far the front runners are bake on paint from Brownell's and a home brew anodizing setup. There is info on the internet, but then again, they sell bridges there too. I am looking for somewhat more reliable/first hand info if possible.

Anyone here done it themselves?

Pointers?

Most of the internet info says to dye in a separate step after anodizing but before sealing with heat, but it seems that some are adding the dye to the acid bath. Is there a right/wrong way here?

I can round up a manual battery charger and the chemicals are easy-peasy to get and should be good for several uses (unless I am mistaken).

[akajun]

I have done my own clear coat anodizing on various parts I have made, but I never messed with the dye, as I hate that stuff. I have a habit of coloring everything in a 5 mile radius. Anyway the clear coat anodizing did increase the surface hardness. The trick is to degrease, then beadblast, then lye bath till the water beads off the part, then anodize. I use a 12v charger, battery acid, aluminum wire, and scrap aluminum for the anodes.

[Jim_P]

I have tried it and it didn't come out as well as expected. Tried both RIT dye and the one sold for the purpose on the Internet. I think my sacrificial Anode was not the right Aluminum alloy. I did get color. It has been permanent. Just not as deep and rich as you see from professional (industrial) anodization.

[Rick Hodges]

My experience with home anodizing was attempting it for small car parts...(dash knobs, breather elbows etc.) I made the parts for a friend who tried the anodizing using RIT dye. The effort was disappointing. It did color the parts with a pale translucent shade that was not bad looking....just not what we wanted. We never did figure out how to give a deep colored finish.
I wouldn't consider using it on an AR, at least not the way it was working for us.

[matrixcs]

I have done some anodizing. It was much simpler than I expected. I did not use sulfuric acid in the process I used the swimming pool ph down dry acid to make the anodize solution and an old computer notebook power supply. I used a large sheet of lead for the cathode which worked well. The slower the process is it seems to make the anodize harder. I was doing 6061 aluminum... various alloys act differently..

[rtracy2001]

See, I learned something. Every article I found on the net says use lead for the sacrificial anode, not one mentioned aluminum.

[Jim_P]

See, I learned something. Every article I found on the net says use lead for the sacrificial anode, not one mentioned aluminum.


I followed these recommendations:

http://www.observationsblog.com/sciencetechnologyexperiments/anodizing-and-dying-aluminum-without-battery-acid

[mactool]

Try this instruction video http://www.diyguns.com/product_info.php?products_id=118&ecSid=d2eaff7cd5c1e8cfbd93fa951118f959

[matrixcs]

Pointers...
Make sure there is good electrical contact with the part to anodize.. It can not be reconnected if the contact fails because the part becomes non-conductive.
aluminum turns yellow when an is anodized.. be sure to leave it in long enough or the color you dye it will be thin..
cleanliness is crucial spots galore when not clean..
lye bath before anodizing will make for a matte finish ... too long a soak will change dimensions..
The lye bath will also remove a poor anodize if you want to try again...

[Ballistics in Scotland]

All aluminium is coated with invisibly thin oxide, which forms naturally whenever a new surface is exposed to air. In theory it ought to be at least as chemically active as magnesium, which you can light with a match in a thin ribbon, or by a momentary electric charge in the magnesium wool which used to be inside photographic flash-bulbs.

It isn't difficult to create a better version of this coating by anodizing. But it is still so thin that although it is the same substance used in aluminium oxide abrasive wheels and paper, it is easily scraped through. Hard anodizing is much more durable, and that is often used in commercial gun parts. But it demands careful temperature control at a temperature close to the freezing point of water, and higher voltages.

Information on websites may be good or bad, but Wikipedia, although not a how-to guide, is subject to challenge by the engineering and scientific community. The websites of individuals aren't.

https://en.wikipedia.org/wiki/Anodizing

[nicholst55]

I was planning to try home anodizing on some AR receivers, but the more I read, the less likely it seemed that the results would be satisfactory. I think it would be very, very difficult to do an actual hard-coat anodizing job at home. I ended up using GunKote on mine, with somewhat mixed results. My surface prep wasn't adequate, and the results plainly demonstrate that.

[knfmn]

I've done home anodizing and it isn't all that hard, but I think that you'll be better off getting a cerakoting setup. Easier to do and it works better, IMO. If you're stuck on anodizing at home, the best tips are to make sure that whatever you're anodizing is clean. Clean it and clean it some more. Any grease, dirt, etc will mess things up. Make sure that there is no metal other than Aluminum going in the bath with your part. I found this out the hard way with an 80% lower. It had a screw to hold the bolt release that was steel. The whole thing wound up being a weird purple/rainbow. Blasted that off and cerakoted it with great results.

Honestly, if it's going to be a beater gun and you only see yourself doing one or two, the bake on finish from Brownells might be a better choice.

[rtracy2001]

Lots of info, Thanks. Still haven't made up my mind as far as coating it goes, but I just couldn't help myself this afternoon and put it together. It doesn't look bad the way it is.

144807

Took me more than 20 years, but I finally got one.

[destrux]

I anodized some silencer parts that I made in an effort to help them resist wear and make them easier to clean. I had some difficulty with my power supply though. You really need something with adjustable current and adequate voltage. I was using a 12v battery charger that had two settings: 12v 1.5A, or 15v 5A. The problem was the higher setting was too much amperage to start off with (if you don't ramp the amperage up slowly it will burn the wire connection and the part won't anodize), and the lower setting was inadequate voltage to kick the process off. The only parts I had success with were the larger parts that I could use the high setting on.

A variable amperage 18v power supply would be ideal...