If you’re like many AR builders who used a raw (unfinished) 80% lower, then coating that bad boy is the last critical step in your AR build project! Like every other builder, you’re trying to weigh the pros and cons of Cerakote and good ole’ anodized finishes. By the end of this post, we think you’ll know which coating is best for your build. Let’s begin!
Anodizing Your Raw 80 Lower
Anodizing is what the majority of standard AR-15 80% lower receivers are finished with. Anodizing is an electro-chemical process. With the right tools (and serious safety precautions) you can anodize your raw 80 lower at home. Anodizing protects an 80 lower from the environment quite well. It’s incredibly durable, corrosion resistant, and it’s sexy.
The anodizing process described below will yield a “sulfuric acid anodized” finish. This is not a Type III hardcoat anodized finish, but this finish can be easily dyed at home to obtain the same look, color, and texture.
WARNING: This process requires the use of sulfuric acid. Extreme precaution must be used at all times.
Interacting with sulfuric poses an extreme risk of serious injury or death if not handled appropriately. Protective gloves, clothing, and eye wear must be used at all times. The steps below are intended to be a summary of the process, and should not be followed step-by-step by an inexperienced person.
What you’ll need:
- Sulfuric acid
- Aluminum wire
- Aluminum foil
- Polyethylene tray or tub
- Liquid temperature probe
- Battery charger or adequate power source
- Distilled water
- Baking soda
This process involves creating a cathode (negatively charged aluminum foil) and an anode (positively charged lower receiver), and submersing the pair in a solution of sulfuric acid and distilled water. Current is then applied using a battery charger and the oxidation process occurs, coating the raw lower with an anodized finish! You must wear gloves, a face mask, and proper eye, face, and body protection during this entire process:
- De-grease your lower receiver. It must be completed free of surface contaminants, grease, and oil.
- Fill a clean polyethylene tray or tub with sulfuric acid and distilled water. Make the mixture 1:1.
- OPTIONAL: Surround the container in ice to lower the solution’s temperature. This will help to produce a better finish.
- Wrap a loop of aluminum wire tightly around the lower receiver. The thicker the better. Leave enough wire to safely protrude above the tub or tray.
- Create a tightly wrapped, round ring approximately 1″ thick, using aluminum foil. The ring should be large enough to surround the receiver by about 3″ to 5″.
- Create an extension of aluminum foil, in similar fashion to the ring, long enough to protrude to the top of your tub or tray.
- Tightly wrap the extension around the aluminum foil cathode. Allow it to protrude atop the container.
- Submerse the lower receiver into the solution with the aluminum wire.
- Connect the positive terminal of the battery charger to the aluminum wire.
- Connect the negative terminal of the battery charger to the aluminum cathode extension.
- Apply current through the cathode and anode using the battery charger or power source.
At this point, you’re anodizing! You should see fizzing occurring in the solution. The lower must remain submersed in the solution for at least 1 hour and 15 minutes. The current can then be terminated, and the lower removed to inspect the anodizing process. You should see a nice platinum or bronze tone appear. Submerge the lower in distilled water to neutralize remaining acid.
Once anodized, your 80 lower can easily be dyed at home! You can find numerous at-home dye kits to produce a hard, flat, baked finish that’s identical to a Type III Hardcoat finish.
Benefits of Anodizing Your 80 Lower:
- More durable finish
- Mil-spec (If Type 3 anodizing)
- Longer-lasting finish
- Requires less maintenance
- A cheaper finish to apply
- Anodizing bonds to the aluminum
Cerakoting Your Lower:
Cerakote is another popular finish many AR builders choose for their raw 80 lower. Unlike anodizing, Cerakote doesn’t bond to the metal. Nonetheless, it produces a hard, durable coating that’s attractive and customizable. Cerakote takes the form of two liquid chemicals (color/coating, and H-series hardener) that are mixed and applied as a spray. Spraying Cerakote requires the use of an air gun. An HVLP spray gun can be used, though a gravity feed airbrush can be used as well.
Most of the difficulty of applying Cerakote is found in preparation.
What you’ll need:
- Cerakote Firearm Finish Kit (4 oz.)
- Canned air
- Fishing line or wire
- Residential oven
- Plastic container
- Chemical de-greaser
- Automotive paint filter
- HVLP gun with 0.8 tip
- Air compressor (20 to 25 PSI minimum)
The preparation steps
- Submerge your raw lower in chemical de-greaser for 30 minutes. A simple spray-down will not do.
- After 30 minutes, remove the raw lower and place it in the oven.
- Leave the lower in the oven at 250 degrees for 30 minutes. This “off-gasses” any remaining de-greaser.
- At this point, the lower cannot be touched or contaminated by anything. Wear gloves from here on out.
- Remove the lower from the oven and inspect it. If there are any wet spots, repeat steps 1 through 3.
- Find a location to spray your lower. It should be well-ventilated and clean. Ideally, it should be free of any dust.
- Plug any threaded fittings and small holes. Although Cerakote applies very thinly, it can still gunk up threads.
- Use fishing line or wire to hang your lower for spraying.
Your lower’s ready to be sprayed! Now you need to get your air compressor, HVLP gun, and Cerakote ready to go. Ensure your air compressor is set to 20 to 25 PSI, and ensure your HVLP gun is equipped with a 0.8 tip. Be ready to fill the gun’s container once you’ve mixed your Cerakote. Once mixed, Cerakote has a shelf-life of 2 hours (open container) or 4 hours (closed container).
Prepping and spraying your Cerakote
- Follow the instructions provided in the kit to mix the Cerakote and hardener.
- Strain the mixed solution through an automotive paint filter to remove contaminants in the solution.
- Pour the mixed Cerakote solution into the HVLP gun’s container.
- Start spraying your lower’s first coat!
- Spray 3″ to 5″ away to prevent build-up or runoff
- Adjust the spray pattern by 1″ to 2″ with each pass
- Spray until the lower has one full, even coat (no faded spots or visible aluminum)
Cerakote can be applied with just one coat. If you wish, you may apply a second coat. Before applying a second coat, the lower must be flash-cured in the oven for 15 to 20 minutes, at 250 degrees.
Curing your Cerakote finish
- Place or suspend your coated lower in the oven with steel wire (use caution and care).
- Until cured, the coating will be wet and can be ruined.
- Cure the lower at 250 degrees for 2 hours.
Fixing a mistake
- If you experience build-up, runoff, or a mistake, do not attempt to touch it or “wipe” it away.
- Place the lower in the oven and flash-cure at 250 degrees for 20 minutes.
- Remove the lower, lightly sand the blemish, and re-spray.
Benefits of Cerakoting Your 80 Lower:
- Make your own, custom finish!
- Baked and incredibly durable
- Easier to do than anodizing
- Optional camouflage kits available
(Photo credit to VitalGear who has a really great cerakote tutorial on YouTube)
Which coating is better?
On durability, the answer’s up for debate. An anodized finish bonds with the raw aluminum, penetrating its alloy structure. This means that with normal wear-and-tear, an anodized finish will technically last longer. Anodized finishes also tend to wear better, producing an aesthetic “grunge”, akin to battle-wear. Cerakote is an incredibly hard, baked and cured finish. Many users attest to its seemingly bombproof ability to withstand hard impacts. Once Cerakote is removed, however, raw aluminum will be present.
Either one will look fantastic. We hope with our guide, you have the mindset that you can apply either of these coatings at home — with the right research, safety, and precautions.