Author Topic: Cheap home anodizing AR15  (Read 15928 times)

Offline thinwater - BANNED MEMBER

  • BANNED MEMBER - BANNED MEMBER!!!!!
  • Full Member
  • ***
  • Posts: 232
Cheap home anodizing AR15
« on: July 06, 2008, 10:17:28 PM »
I have to take 64 uppers to the anodizer on monday but since I have this gun building sickness I decided to do one at home today. I decided that not  having any anodizing equipment would not stand in my way. I poured 1 qt of battery  acid into a plastic box with two quars distilled water. I polished up  an upper, washed it with dish soap (for degreasing) then gave it a quick dunk in a dilute (about 2 oz nitric acid to 2 qts water) nitric acid bath for general cleaning just because I have some (for disolving broken carbon steel taps from high value AL parts). I rinsed it in distilled water  and mounted it on a titanium rod. I did not have any lead for the cathode so I used 6061 Al plate. I dunked it in the acid and hooked up the battery charger. One hour later it had a nice dull lemon shade to it. I made the dye with Rit from Walmart (Not very good but the best I could come up with on a Sunday on a holiday weekend). I pre heated the dye to about 120 degrees and soaked the anodized upper in it for 4 hours while in a stainless ice cream tub. Then I boiled it for ten minutes in the same tub full of dye. It came out pretty good for the time and equipment used. A proper dye would have made a huge difference.

Offline thinwater - BANNED MEMBER

  • BANNED MEMBER - BANNED MEMBER!!!!!
  • Full Member
  • ***
  • Posts: 232
Re: Cheap home anodizing AR15
« Reply #1 on: July 06, 2008, 10:19:06 PM »
The receiver in the dye.

Offline thinwater - BANNED MEMBER

  • BANNED MEMBER - BANNED MEMBER!!!!!
  • Full Member
  • ***
  • Posts: 232
Re: Cheap home anodizing AR15
« Reply #2 on: July 06, 2008, 10:20:27 PM »
Finished.

Offline Grizzly_A

  • Newbie
  • *
  • Posts: 6
Re: Cheap home anodizing AR15
« Reply #3 on: September 01, 2008, 06:30:01 PM »
What did you set your battery charger at?

Offline Prototype Services

  • Sr. Member
  • ****
  • Posts: 456
Re: Cheap home anodizing AR15
« Reply #4 on: September 01, 2008, 07:10:28 PM »
Did this come out as a "hard" anodizing or just a colored anodize?
I would certainly like to know a way to hard-anodize at home.

Offline hockeyduck

  • Newbie
  • *
  • Posts: 5
Re: Cheap home anodizing AR15
« Reply #5 on: November 28, 2008, 05:10:44 PM »
I have'nt heard anybody talk about powder coating the lower is there a reason why.

Offline Loadedagain

  • Newbie
  • *
  • Posts: 7
Re: Cheap home anodizing AR15
« Reply #6 on: November 30, 2008, 10:40:09 AM »
I have'nt heard anybody talk about powder coating the lower is there a reason why.

powder coating will add too much material to maintain clearances, while anodizing typically removes a thou or two.

Offline StarDog

  • Jr. Member
  • **
  • Posts: 86
Re: Cheap home anodizing AR15
« Reply #7 on: November 30, 2008, 04:11:27 PM »

powder coating will add too much material to maintain clearances, while anodizing typically removes a thou or two.
[/quote]

I would have to contend that.  We send a lot of aluminum out to anodize where I work, it typically comes in with an additional .0002" (called .0001" buildup per side) to .004" overall.  You can remove material by stripping away anodize and reapllying it, because it usually penetrates the metal as deeply as it builds up.

Offline Loadedagain

  • Newbie
  • *
  • Posts: 7
Re: Cheap home anodizing AR15
« Reply #8 on: November 30, 2008, 06:15:21 PM »
I would have to contend that.  We send a lot of aluminum out to anodize where I work, it typically comes in with an additional .0002" (called .0001" buildup per side) to .004" overall.  You can remove material by stripping away anodize and reapllying it, because it usually penetrates the metal as deeply as it builds up.

fair enough. maybe i'm remembering a number following chemical etch. either way anodizing dimensionally alters a part much less than powder coating.

another problem with powder coating (for this application) is inconsistency. it is often applied through a spray gun, which can lead to thick and thin areas.

Offline Tango Chaser

  • Tango Chaser Tactical LLC
  • Sr. Member
  • ****
  • Posts: 616
Re: Cheap home anodizing AR15
« Reply #9 on: November 30, 2008, 06:57:43 PM »
The cheap home anodzing is not "Hard coat" anodizing. It's just a color anodizing, so keep in mind the aluminum is still soft and can wear faster.

Offline goober

  • Sr. Member
  • ****
  • Posts: 1632
    • goober on heatware
Re: Cheap home anodizing AR15
« Reply #10 on: November 30, 2008, 08:23:00 PM »
"home anodizing" is type II or room temp anodizing. it imparts a true anodized coating on an aluminum, but the coating is less thick and robust than that created by type III or "hard coat" anodizing, which requires different acid concentrations and most notably drastic temperature control; the acid bath must be chilled strongly to achieve the desired effect.
anything that is "type III mil-spec hard coat anodized" uses the latter method... most parts done by some goob (including me) in their garage, are Type II, (which is pretty tough), unless otherwise noted.
heatware username: goober

Offline Hunter01

  • Newbie
  • *
  • Posts: 22
Re: Cheap home anodizing AR15
« Reply #11 on: January 01, 2009, 07:48:13 PM »
Where do you get Nitric acid? that is the one thing I couldn't find while learning this process. I used Purple cleaner from Auto zone it worked well on my second atempt. Also found liquid form of ritz and it did much better than the powder form I tried last time. I got green the first time around I think I made a number of mistakes. Didnt get a good conection on the electricity for the first 1.5 hr S Realized it and left it for the next 1.5 hr with it working right. didnt get the die tempature up to 140 d. first time ( was doing it on a gas grill burner ) Today went much better. I did get some small freckles where the die didnt take but very small.

Offline thinwater - BANNED MEMBER

  • BANNED MEMBER - BANNED MEMBER!!!!!
  • Full Member
  • ***
  • Posts: 232
Re: Cheap home anodizing AR15
« Reply #12 on: January 02, 2009, 12:43:36 AM »
Where do you get Nitric acid? that is the one thing I couldn't find while learning this process. I used Purple cleaner from Auto zone it worked well on my second atempt. Also found liquid form of ritz and it did much better than the powder form I tried last time. I got green the first time around I think I made a number of mistakes. Didnt get a good conection on the electricity for the first 1.5 hr S Realized it and left it for the next 1.5 hr with it working right. didnt get the die tempature up to 140 d. first time ( was doing it on a gas grill burner ) Today went much better. I did get some small freckles where the die didnt take but very small.

I just used the nitric acid because I read that some big places do this. I would not try and buy any now due to excessive big brother watching it's sale to individuals. Getting it clean is the most important thing and maintaining good electrical contact.

I just finished another lower at home and I think I will order some proper blue dye to  do it with so it comes out better than my Ritz attempt. I don't want to take it to a commercial anodizer since it has no numbers on it. A couple of "Sterile" guns may be a good thing to have.

Offline Hunter01

  • Newbie
  • *
  • Posts: 22
Re: Cheap home anodizing AR15
« Reply #13 on: January 02, 2009, 05:15:52 AM »
I agree

Offline govtcontact

  • Newbie
  • *
  • Posts: 2
Re: Cheap home anodizing AR15
« Reply #14 on: February 12, 2009, 07:27:36 AM »
Figured I better mention a key point: You need to monitor the voltage and current while doing this.  As the anodizing progresses and the coating gets thicker, the voltage will rise and the current will lower.  At some point the voltage will start to lower and the current will rise.  This is where you stop as the anodizing is now starting to be removed.  (Anodizing is not a one direction process).

Offline goober

  • Sr. Member
  • ****
  • Posts: 1632
    • goober on heatware
Re: Cheap home anodizing AR15
« Reply #15 on: February 12, 2009, 07:54:59 AM »
Figured I better mention a key point: You need to monitor the voltage and current while doing this.  As the anodizing progresses and the coating gets thicker, the voltage will rise and the current will lower.  At some point the voltage will start to lower and the current will rise.  This is where you stop as the anodizing is now starting to be removed.  (Anodizing is not a one direction process).
Good point... Another (complimentary) method is to use a formula based on desired thickness and Amps/ft^2 used, to determine the total time to anodize, and use of a lab-grade constant current/constant voltage power supply is desirable.
heatware username: goober

Offline FNFAL762

  • Newbie
  • *
  • Posts: 4
Re: Cheap home anodizing AR15
« Reply #16 on: February 23, 2009, 08:17:28 AM »
Every sight I go to talks about hard coat, color, wear, and so on. So here is my two cents. If back in the early eighties you walked into a little two man shop in South Porland, ME known as Quality Parts (aka Bushmaster Firearms) you would have seen the armorer spray painting the lowers with Gun Kote and baking them in a toaster oven. No **** So anyone that owns a class III from Sendra or any lower that came out of that shop, that is what you got. Sounds pretty cheap but my sendra has held up well over the years of full auto abuse. Later after they moved out to Wyndom, ME I bought another lower that was hard coat anodized that looks as nice as the day I bought it.

Also has anyone ever thought about trying black walnut hulls boiled in water as dye. When I was a kid I used this to dye and prevent rust on steel animal traps. I would boil water on top of the wood stove in a metal five gallon bucket and drop in a dozen black walnuts still in the green hulls. Then dip the traps and let soak until they were as dark as I wanted them to be. The color stayed on the metal really well just don't get it on your hands I don't know of anything short of time that will get it off.

Offline IOWOLF

  • Full Member
  • ***
  • Posts: 114
Re: Cheap home anodizing AR15
« Reply #17 on: February 23, 2009, 10:39:04 AM »
I have'nt heard anybody talk about powder coating the lower is there a reason why.

powder coating will add too much material to maintain clearances, while anodizing typically removes a thou or two.

I Powder  coated both my receivers with out any problems.

Offline Beau52501

  • Jr. Member
  • **
  • Posts: 95
Re: Cheap home anodizing AR15
« Reply #18 on: March 18, 2009, 02:08:18 PM »
Did you do your own powder coating or have it done?

There is a place in Hedrick,Iowa that I heard does great work on powder coating although I have not had the chance to check it out yet.

Offline IOWOLF

  • Full Member
  • ***
  • Posts: 114
Re: Cheap home anodizing AR15
« Reply #19 on: March 18, 2009, 02:29:05 PM »
I do my own.

 There are places all over Iowa that do it, a guy in or around Oakland is doing the steel for the I 80 Mo. river bridge.

 Yes ALL of it.