In-Shop Powder Coating: A Durable, Easy-to-Apply Finish

Since iron was used to make the first tool, rust has been a problem. Animal fat, grease, oil, paint, and finally bluing have all been used in an effort to protect metal from oxidation. To me, my beautiful blue 6-inch Python is about as good as the bluing process gets. But it is still blue. Blue or brown are pretty much our only choices, unless we go to plating. Chrome, nickel, silver or gold are our plating choices. But what if we could plate with rockhard plastic? Welcome to the world of powder coating.

I got the idea that powder coating might work on guns about 15 years ago when I turned my carand cycle-building business back into a hobby, and made my gun hobby into my primary business. From my experience with street rods, I knew that a beautiful paint job could last for many years with some TLC, but all the stuff under the car would take a beating from rocks, gravel, and road debris. Paint chipped too easily, and adding a hardener helped but didn’t completely solve the problem.

Chrome looked nice, of course, but was expensive and required constant cleaning to keep it from rusting. When powder coating came along in the 1980s, street rodders jumped on it. This hard, durable finish was available in almost any color, but it was still expensive to apply in those days. To make powder coating gunsmith-friendly, the price had to come down, and the process had to become "small-shop" practical. Both problems have now been solved.

If you do a little poking around on the web, you’ll find several powder-coating kits starting at around $100 from sites like harborfreight.com, eastwoodco. com, caswellplating.com, and others. And you’ll find powders in dozens of colors and finishes (even metallic) for prices that run about $10-12 per pound. A pound of color would be enough for a small arsenal of guns.

Harbor Freight has an oven for about $400, but I found a toaster oven at Wal-Mart for less than $30 that was big enough for a handgun and would heat to 450 degrees. Of course, you can use the oven in your kitchen (maybe), and infrared heat lamps can also be used for fusing some powders. The Powder-Coating Process In case you’re not familiar with the process, powder coating is not really a "painting" process, but is more like plating.

Many gunsmiths have elec troplated triggers, hammers, safeties, and so forth, and understand that a negatively charged part attracts a positively charged material. Powder coating is a similar process. The part has one charge (either positive or negative) and the powder has the opposite charge. When the ultra-fine powder is released into the air from the low-pressure spray gun, it floats

The powder colored the grips nicely, but did not fill in the checkering. The frame rails were not coated; a careful brushing off before heating allows easy removal from unwanted areas. over to the part and attaches itself. The powder, in fact, is so fine that if you blow on it gently, it floats into the air like smoke. When the part is heated, the powder melts into the pores of the substrate metal producing a tenacious bond, and the surface fuses into a smooth, glossy surface.

Matte-finish powders are also available. The items needed for this process are fairly simple. In addition to the kit, which will include the spray gun, transformer and controls, you’ll also need an oven that will heat to 450 degrees. You’ll need the powder in the color and finish of your choice, a compressor that will put out 10-15 psi, a cleaner to prepare the metal, and wire or some form of a jig to hold the parts to be coated.

The following is a step-by-step process that worked for me. • Make sure the gun is unloaded and strip the parts to be coated. • Sandblast the parts, then clean with a cleaner that will not leave any residue. I used brake cleaner. Don’t touch the parts after cleaning, as body oils may cause poor adhesion. Touch only in areas that will not be coated. • Make a jig that will hold the parts while they’re being sprayed and heated.

Heavy wire will work in most cases. • Tape off any areas you don’t want coated, and follow the instructions that come with the kit for applying the powder. After spraying, remove any tape and double check to be sure you have complete and even coverage. • Gently place the parts in the oven so they will be evenly heated. Heat the parts at the temperature suggested and for the length of time specified in the instructions. After the parts have cooled, remove them and trial fit them to the gun.

In my first experiment, I realized I had put too much powder on the bottom of a slide and I had to file it off. Sandpaper would have worked as well. Some Helpful Tips Overspray is not a problem if a surface like wood or paper is used to spray on. The powder does not make a permanent bond until heated. Overspray can be saved for later projects. Taping off some areas can be tricky.

If you find it hard to mask off an area, you can simply use a small artist’s paintbrush to gently remove the powder from areas you don’t want to cover prior to heating. Try powder coating a few hand tools before trying gun parts so you can get the "feel" of how to do it. You might first experiment with a few pieces of pipe sandblasted and sprayed with different amounts of powder, and then heated. This will give you a good idea of what to expect from the finished product.

If sandblasting is not available, scuffing with sandpaper should work also. The bigger your oven, the more you can do. Be sure it will heat to at least 400 degrees. Be very careful when moving a coated part to the oven. The only thing holding the powder on the part is the part’s rough surface and static electricity. A cardboard box cut so you have three sides and a floor makes a great little spray booth. Some powder-coating spray guns may use the positive wire on the part rather than the negative.

As long as the part is charged opposite to what the powder is, it should not matter. Opposites attract. Conclusions Like most new processes we tackle, this will be a trial-and-error process that will take a little practice. But the possibilities are endless. If Semper Fi is your motto, imagine a desert-tan slide on an olive-drab frame with Marine Corps grips. Personally, I’m ex-Navy and plan to build a 1911 with a navy-blue slide, battleship gray frame, and ivory U. S. Navy grips.

And how about that old wall hanger that’s too pitted to reblue? If you can fit it into an oven, put a heavy coat of dark blue or black powder on it, sand it smooth, and then buff it back to a nice shine. With a nice powder-coat finish, you might not be ashamed to take it back into the field. ■