Well I have done several 80% lowers and feels it's time to take the next step.

Just curious how hard it is and any tips I need to know about.

Thanks

Anyone?

It's pretty fucking involved, but damn near anything is doable, if you really want to.  It usually involves heated chemical tanks, and electric currents, and strict time limits.  Hard to pull off in the home setting.

Another option would be to alodine dip it, and then coat with Cera, KG, etc.

The alodine is just a room temp bath that provides corrosion pro for the base metal before a coating is applied.  Used extensively in the aviation industry for airframe repairs.  Good field expedient since it requires no heating/current.  You can get a gal jug at aviation supply houses, like Aircraft Spruce.

It turns alum a golden brown color and adds a thin film of corrosion pro.  It is then fresh water rinsed, to stop chemical reaction.  Not as durable as a hard anodizing, but gets you in there as a base coat for other products.

It can be a little intimidating the first time you do it. Just get everything lined up before hand and have a written procedure in front of you. This is what I put together and have run several lowers through the process.

I didn't color the anodize and used Gunkote instead. I picked up color from Caswell for the next time. Plan on using heating coils (already purchased) along with Temperature sensor/controllers and skip the GunKote.

Shopping list:
¼” aluminum rod 36”. I used a die set to put ¼-28 thread on one end so it could be screwed into the pistol grip screw hole on the lower. This rod can be reused since there is no anodizing build up at the threads. Snug with pliers prior to anodizing. Also cut shorter 4” pieces off the rod and thread to use as handles when doing other steps so the part is not touched. Drill a hole in a piece of wood and insert rod and use as a stand when doing the K-Phos/Gunkote steps.

Battery charger - I used an older 4 amp 6/12V. I was trying without success to find a reasonably priced rheostat for adjusting voltage and then gave up and just started at 6V for 5 minutes then switched to 12V for the remainder of time. In my case the amp gauge pins at max for a few seconds when first turned on, then settled down to rest at 2A @ 6V and about 3.5A @12V.

H2SO4 - Sulfuric Acid - Autozone had QT size and O'Rielly's had Liter. Same price but the QT is slightly larger. Mix 2 QT's into 1 ½ gal DIH2O.

HNO3 - Nitric acid - pH down by Tetraflora – bought this from a local hydroponics store for $9/QT. After a lot of research, it was the cheapest way to get nitric acid. Nitric Acid was the most difficult chemical for me to find at a reasonable price. You only need 10% for the desmut step. You can also wash/scrub the lower again in dish soap and get most of the smut off, but if you want to do textbook, use HNO3.

Lower anodizing  procedure
Do not let part dry anytime during the anodizing process steps 1-4.
1.One day prior to anodizing - Add 1 part battery acid (H2SO4) to 3 parts DI H2O. Slowly add acid to H2O. 2 qts battery acid, 1 ½ gal DI water. The solution needs to cool down before anodizing.
2.Degrease – materials: dish soap, Purple Power or Greased Lightening, acetone

Wash with Purple Power, rinse tap water, wash with dish soap, rinse tap water then DI H2O rinse, dry, soak in acetone 10 minutes. Dry
3.Etch – Red Devil Lye 2 tablespoons per gallon DI H2O. 120g/L
-Attach AL rod to lower to use as a handle.
-NaOH bath 2-5 minutes, agitate every so often until a greyed/blk.
-Spray DI H2O to rinse off over NaOH bath.
-DI water bath covering lower, agitate, pour off and change water let soak for a few minutes.
4.Desmut – 10% Nitric Acid bath (Techniflora pH down)
-3-5 minute turns white. Agitate in bath.
-Spray bottle with DI water
-DI water bath covering lower, agitate
5.Anodize
-H2SO4 should be at 69° - 72°F, use glass aquarium thermometer.
-Use air stone with aquarium pump to circulate the bath.
-Replace short AL rod on lower with longer rod for anodizing.
-Battery charger - Negative (cathode) to lead/AL in bath, Positive (anode) to AR lower AL rod.
Start at 6V for 5 minutes (mine held at 2A). Switch to 12V for remainder of time (mine held at 3.5A).

Read amperage and calculate time.
If power supply reads 3.5A:

720/3.5 = 206 amp min  
81 sq in/144 in/ft = .5625 sq ft  (81 sq in is the lower surface area)

206 x 0.5625 = 116 min in tank @ 3.5A

Spray bottle with DI water over tank
Soak in DI water, change water soak several minutes
Dry several days before Gunkote process

Coloring will delete the drying step above and add color in heated tank followed up with hot H2O bath to seal the pores of the aluminum.

Hope this helps!

Thanks

Huh.  Yeah like I said, piece of cake.