I have been interested in doing powder coating for a number of years but this does entailaddtioinal equipment and space (and spousal buy-in). I have been frustrated with conventional finishes (paint, black oxide, etc.) for my metal working projects. Paint takes a long time to dry, requires multiple coats, decent temps to spray and is not friendly for spraying indoors (and we live in Wisconsin – so this is important for half of the year).
With my recent retirement (yeah!), I was nearing hte completion of redoing my daughter’s kitchen. At this point I was looking to the next few projects (redoing house exterior lights, redoing bridgeport and SBL controls, new exterior path lighting, David’s motorcycle, etc). These would mean either lots of spray painting and future redos or we could get this done with powder coating. For example, I cleaned up and then had professionally powder coated the crash bars/ engine guards for my bike (Honda VTX-1800) which cost $120. Talking with the shop guys at HyTech Powder Coating in Waukesha they said the typical minimum is $80-120 or small projects. While they did a great job, I restarted thinking about a DIY approach and being able to do powder coating as needed.
Powder coating involves:
- Mechanically cleaning the part to enable good finish adhesion. This typically means abrasive blasting and chemical wipe.
- Electrostatically spraying a paint powder on the part
- Baking the coated part to fuse and cure the powder into the final finish
This is basically similar to conventional spray painting. However there are some similarities and differences. :
- Prep in either case is key. However Powder Coating does seem to place greater emphasis on mechanical bonding and hence the need for abrasive blasting.
- Spraying the finish requires a special gun but this is in the same price range as a decent HVLP spray gun. Masking of areas not to be painted requires either silicone plugs or special tapes due to the high temperatures used in the curing. I picked up the Eastwood dual voltage powder coat gun.
- Oven for curing . This can be as small as a toaster oven or a room sized monster used for powder coating car chassis. For the work I will be doing, a home oven is big enough. DO NOT think you can use your regular home food / baking oven for both purposes. Plus you will need additional ventilation for the fumes. Fortunately, used stoves / ovens (esp. wall ovens ) are dirt cheap. You do want a convection oven. Check your local Habitat for Humanity Restore or Craigs List. I got mine at Habitat Restore in Waukesha, WI . A 30″ GE Profile convection oven for $25 (~1% of the original price) . This wall oven did require a basic cabinet in which to reside (which would also get drawers and drawers eventually).
- Rack to hold the pieces while spraying. I picked up a stand from Eastwood but it was designed for elves or dwarves and had to raise the top by 3 feet to bring it to a workable height.
- Blast cabinet. This was the most costly item both in initial purchase price and parts for modifications. I bought the Harbor Freight 40 lb blast cabinet (with the 20% off coupon). However doing the necessary mods basically doubled the price in added parts. Check youtube for the many videos on souping it up. Must haves: caulk ALL the joints form the inside with Vulkem – it leaks powder like a sieve, metering return line off of the dump chute to feed the blast gun, lowering the grate inside, adding a separate pressure regulator for the gun, additional baffling for air intake and extraction, dust deputy cyclone ahead of the shop vac, new lighting, wheeled caster base, additional outlets for shop vac and powder coat gun, EZ open wing nuts for the window for replacement / maintenance. Yes this sounds like a lot but think of it as a “partial kit” and go from there. Besides my 4yo grandson – Sawyer had a lot of fun helping. Good thing it was all metric as I taught him to grab the 8, 10mm wrenches vs trying with imperial fractional sizes.