Monday, July 18, 2011

Powder Coating–Part 1

My last post covered the bead blasting portion of the powder coating preparation process.  This post covers the rest of the prep and set-up for powder coating.
Excerpts from Wikipedia: 
Powder coating is a type of coating that is applied as a free-flowing, dry powder… The coating is typically applied electrostatically and is then cured under heat to allow it to flow and form a "skin". … It is usually used to create a hard finish that is tougher than conventional paint. Powder coating is mainly used for coating of metals...
The reasons I’m choosing powder coating vs. painting is because powder coating provides a tougher finish than paint, is less likely to run, and (in my opinion) looks more like the original Japanned finish.  The big down-side is that powder coating requires special equipment.  Since my dear husband has a powder coating set-up I really don’t really see a down-side at this point.(Disclaimer:  if you ask me when the project is done I may have a different opinion – we’ll see!)
Anyway, one key to powder coating is to make sure the parts are clean and have a properly prepared finish.  Then you need to hang them from a metal bar using metal hooks so that electricity can conduct through the metal parts. 
parts ready for powder coatinggear cover - powder coat ready

Another key point to remember (which I almost didn’t!) is that the powder will adhere to anything with an electric charge and will flow into cracks and crevices during the curing process. This is great for a smooth finish, but not so great if you don’t want the threads of your screw holes to get covered.  To solve this problem you can order special plugs to cover the threads in the hole which will keep them free of powder.  The plugs are made of silicone so they don’t melt in the oven during the curing process.
plug in lamp shadeprotected threads
There is also special high-temp resistant tape that should be used to cover any other surfaces you don’t want coated with powder.  I used this tape on the back-side of the terminal bracket, where a tight fit will be needed.
prepped terminal brackettape on terminal bracket
An alternative to plugs and tape is to sand, scrape, and pick the powder coating off the surface after the fact – not fun.
Now for the equipment.  My husband uses the Eastwood Hot Coat system which is relatively simple and easy to use.  First, the powder (we used gloss black) is loaded into the gun.
Powder coating powderPowder Coating Gun
The gun is attached to a power supply that conducts electricity to the metal bar that creates an electrostatic charge on the metal parts so the powder will stick to it.Power supply  power to rod
The last piece of the set-up is the power switch that is operated by the person doing the spraying to control the flow of electricity to the parts.
power button & cord
One last step – pre-heating the oven to 400°F.  FYI, we do not use our home oven for curing powder coated parts!  Instead we purchased an electric kitchen oven/range from Craigslist for $10 specifically for this purpose.
Set-up complete!  Next step – powder coating!!  Stay tuned….

1 comment:

  1. You definitely made a right choice in using powder coat. It creates a stunning look and long-lasting finish for metal surfaces. Tip: to ensure smooth finishes for your metal, make sure that the metal surfaces are thoroughly cleaned, and it’s free of oil, dirt or grease. Sandblast all the parts to make it as clean as possible.

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