Intro: Powder Coating a Part
I took a powder coating course at TechShop and I was amazed at how easy it is.
I have a part that I am working on that has threads on one end. It is a 3/8" rod that I don't want to rust. I decided to powder coat it to protect it. The only powder that I had was "TechShop Blue", so I went for it.
Before you powder coat a part, you can sandblast it to get all of the oils and grease off of it. Since the part has threads on one end, you don't want to sandblast them. Take some Kapton Tape (it is heat proof to 800 degrees). Wrap the threads with the tape to protect them.
Since any part needs to be grounded when you powder coat, wrap a small copper wire around the threads before you put the tape on the threads.
Step 1: Sandblast ;-)
One of the great things about doing a project at TechShop is that they have the tools that you need to get the job done.
To sandblast, all you need to do is open the cabinet, put your part in it, then close the door. Next, turn on the air pressure, and the blower. Put your hands into the gloves and pull the trigger. In few minutes, your part is sandblasted and clean as a whistle!
Step 2: Pre-Heat the Oven
Pre-heat the oven to 400 degrees. In addition to the small oven that will hold a tool box, TechShop also has a walk-in oven. You can put a motor cycle frame in it!
Step 3: Prep the Powder
Powder costs between $8 - $12 a pound. The powder in the scoop will cover about the same square footage as 10 spray cans. It goes a long way. The amount of powder necessary to cover my part is about 1/4 of a teaspoon.
Pour the powder into a jar using the funnel.
Screw the powder jar onto the gun and turn on the power the the gun.
Step 4: Wash the Part After Sandblasting and Dry Out the Part
Wash the part with a citrus type cleaner or TSP. Make sure to rinse the part well with water.
Hang the part in the pre-heated oven to dry it out.
After about 5 minutes, let the part cool so that it is no more than 100 F. degrees.
Step 5: POWDER COAT!!
Place the part in the powder coating booth. Make sure that the part is suspended in such a manner that it is grounded. If it is not grounded, then the powder won't stick to the part when you pull the trigger. Turn on the fan, then start to powder coat.
Powder coating works by positively charging the powder as it comes out of the gun. You can see how easy it is to get it to stick to the metal. Click here to watch: http://www.youtube.com/watch?v=0x8aYUlh4O4
Step 6: Bake the Part / Then Cool
Place the part in the oven and bake for 12 minutes. Make sure that you don't knock off the powder.
When the 12 minutes is done, transfer the part to cool.
That's all there is to it.
I now have a powder coated part -- I made it at TechShop!