Metal finishing on a firearm is not as complicated as you might think, and the options have changed over the years. In days past, you would have had to have bluing tanks and all the toxic chemicals that process entails. While bluing is still an excellent way to finish a rifle, the hobby gunsmith will likely have better results with spray-on coatings. In fact, with a stainless steel gun, a spray-on coating is the only option for a new finish. A coating-style finish not only looks good, but it will protect the metal from rust better than bluing.
1) GO LAUER: There are several coating-type metal finishes on the market, but most require oven drying. At least one coating, though, DuraCoat by Lauer Custom Weaponry
(lauerweaponry.com) can air dry.
2) TAKE DOWN: The next step in the process is to disassemble the gun as far as possible.
3) CLEAN UP: If the gun is very dirty, clean it in a solvent tank or with spray cleaners to remove most of the gunk.
4) DEGREASE: All the metal must then be degreased with a solvent that dries without residue. This can be done with aerosol spray cans of degreasing agent. But if the barrel and action are together, it’s important to soak the parts in a tank filled with degreaser. If you don’t take the barrel out of the action, oil in the threads can “weep” out of the joint between the action and the barrel and cause the DuraCoat to not stick. On the other hand, it takes some specialized tools to remove the barrel. So soaking in a tank of degreasing solvent solves the problem.
I use TruStrip Solvent available from Lauer Custom Weaponry, and one of their solution tanks. Scrub the part with a small brush and then let it soak for half an hour before removing it and letting it air dry. After that, I handle the gun only while wearing gloves.
5) SANDBLAST: Next, the metal’s surface must be prepared. The best approach is to sandblast the metal parts—to give them teeth—as the rough surface from sandblasting increases surface area for the DuraCoat to grip. Tape off anything you don’t want sandblasted with several layers of masking tape. Plug any holes with modeling clay. An inexpensive approach is to use a gravity-feed sandblaster and consider the sand a consumable. But, if you are going to do many guns you will want an enclosed blasting cabinet where the sand can be recovered and where the blasting is done inside a closed environment. Keep the sandblaster moving and watch the metal so that you have an even sheen to the finish. If you are not using a cabinet, be sure to wear thick leather gloves, long sleeves, a respirator, face shield and goggles for full protection. Don’t forget to sandblast all the small parts that you are planning to coat. That includes the bottom metal, scope mounts, action screws and even the bolt. If you decide to coat the bolt, make sure to tape off the lugs, as you do not want to sandblast or coat them. One thing to remember is that any screw that shows on both sides of the rifle must be prepped and coated on both ends. Once all the metal has an even texture, degrease again if needed and clean up all the sand that might have accumulated in the nooks and crannies.
6) ROUGH THE SURFACE: An alternative to sandblasting is to rough the metal surfaces with a Scotch-Brite pad or emery cloth. DuraCoat can be applied over just about any clean surface and I have simply degreased a rifle and coated over the old bluing, but you will get a better result if you rough the surface before coating.
7) MIX FINISH: Mix the Duracoat and hardener according to instructions and the ratios suggested. Remember that colors can be mixed and blended for a custom look.
8. AIRBRUSH: I normally use a relatively inexpensive gravity feed spray gun that is powered by a shop air compressor. But DuraCoat Finishing has several kits starting at less than $30 that include propellant if you do not have a compressor. It is a simple matter to follow the directions to set up the airbrush or spray gun and to mix the DuraCoat. The key is in adjusting the air pressure and the volume of DuraCoat by testing on a piece of cardboard until the spray pattern is just right. Wear eye protection and a painting mask or respirator.
9) APPLY & LET DRY: Apply DuraCoat in very thin layers, so adjust for a fine spray. Several thin coats are better than one thick coat. After you finish the coating, let it set undisturbed for at least 24 hours. After that, the parts can be handled, but it may take a week or longer to reach its full hardness. How about customizing your rifle even further? You can also add patterns using one of the many stencils available from DuraCoat, or your own imagination. The rifle shown below was done with a laundry bag used for a stencil.
Metal finishing on a firearm is not as complicated as you might think, and…
by Andre M. Dall'au / Jul 1, 2012