Spray coating AR-15 lower receivers with Brownells Aluma-Hyde II


Brownells Aluma-Hyde II is an aerosol product that is easy to apply with great results to many gun parts including AR-15 lower receivers. It comes in many colors and is a great alternative to some of the other coating products on the market that require the use of an air brush and mixing. Like many spray coatings the key to a good finish is surface prep and proper curing. Brownells recommended product for surface cleaning and degreasing is their TCE cleaner. After application of the Aluma-Hyde II you can allow it to air dry for 1-2 weeks or bake it in the oven for one hour at 300F. Let's go through the process of spraying an aluminum AR-15 lower receiver with Aluma-Hyde II.



Obviously you don't want to touch the receiver during the process so what I do is use a long 1/4" bolt with 28 thread pitch and screw it into the pistol grip screw hole of the receiver. This gives me a handle to hold and turn the receiver as I am cleaning and spraying as well as a way to hang the receiver in the oven without any of the coated surfaces touching the oven or racks. When I'm ready to start I prepare the oven by removing all of the racks except one that I put at the very top position. This is where I will hang the receiver. I also get a large binder clip to clip the bolt to the rack and a piece of aluminum foil to act as a heat shield between the receiver and the heating element. Pre-heat the oven to 300 degrees Fahrenheit. Shake up your can of Aluma-Hyde II for 1-2 minutes so it is thoroughly mixed as you would a can of spray paint. Remove the top from the can so you don't have to worry about it while you are holding the receiver.


Start by making sure the receiver is clean of most particles and oils. You also want to make sure the receiver is dry. Once that is accomplished you can thread the bolt into the pistol grip screw hole. We're now going to go to a well-ventilated area to clean and spray the receiver. I highly recommend doing this outside. If it is too cold outside you can help eliminate that problem by keeping the receiver, TCE and Aluma-Hyde II inside and warm until you are just ready to spray. Then bring everything back in to keep it warm. You will want to wear protective gloves at least on the hand you will be holding the receiver with. A fume mask is also recommended.


Thoroughly spray the receiver with TCE to remove any oil that may be left. This will make the surface very dry after the TCE has evaporated which happens quickly. Give the receiver a few minutes to ensure the TCE has fully evaporated. You can also warm the receiver slightly with a heat gun or hair dryer to speed this up. Do not allow the receiver surfaces to touch anything after it has been sprayed so it does not get contaminated.


Next take your can of Aluma-Hyde II, give it one more shake, and then apply a light coat to the receiver. Keep the spray nozzle about a foot from the receiver when spraying. Start with the tougher areas to reach such as the fire control group pocket, receiver threading, under receiver trigger area and the front of the receiver. The sides of the receiver are the easiest to coat so save them for last. Do not spray too heavily as we will be making four light coats of Aluma-Hyde II in total. After the initial coat allow the receiver a few minutes to flash off. You can use the heat gun or hair dryer to gently warm the surfaces to help speed the process but don't go too hot or too close to the receiver.


After the surface has flashed repeat the process again for a second coat light coat. Start with the same nooks and crannies before finishing with the two sides. I have found Aluma-Hyde II is fairly forgiving when it comes to runs so don't try to wipe the receiver if you get one. Just let it dry slowly without heat and it should fade away. Subsequent coats will help cover any minor variations.


Repeat the process a third and fourth time as needed. The final coats will be giving the surface its finished look and you may not even need to spray the unseen areas such as the magwell and fire control group pocket. Focus on a smooth spraying for the final coat as the receiver should already be fully covered by now. Allow the final coat to flash naturally without use of a heat gun or hair dryer.


Pull the nozzle from the spray can and soak it in some acetone to clean it out. Otherwise it can clog up. It's not a bad idea to get the twelve pack of replacement fan nozzles with your order.


Finally we are ready to bake the receiver for one hour at 300 degrees Fahrenheit. Fair warning, this will smell up the house for a few hours. Not terrible but it won't smell like fresh baked cookies either. Being very careful not to let the receiver touch anything, especially in the oven, clip the 1/4" bolt to the top rack. Make very sure the clip is secure so the receiver doesn't fall. I also use a piece of aluminum foil to act as a heat shield between the heating element and the receiver. I want the receiver to cure from the heat of the oven, not from the more direct and extreme heat of the element. Gently close the oven door and set a timer for one hour. After the hour is up shut the oven off but leave the receiver in the oven for another hour so the heat comes down gently. After the hour is up I carefully open the oven door and allow it to sit another half hour with the door open before removing the receiver.


That's it. After curing I spray the receiver with oil which will darken and lubricate it. Wipe off the excess with paper towels and you're ready for assembly with your parts kit.