Powder coating is an electrostatic process in which polymers or plastics are applied in a dry spray. Typically, this process is used for metals, but with the right preparation, it can be applied to other materials such as glass or wood. Powder coating is much more durable than most conventional paint, and creates a thick and even coat.
01. Glass bottle
02. Sheet of aluminum foil
03. Simple green
04. Scrub Brush
05. Wire to hang bottle (about a foot)
06. Powder Coat
07. Powder Gun
08. Powder Coating Oven
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Step 1: Prepare Oven
Turn on the oven according to the temperature provided by the powder you are using.
In this case, I used Columbia Mirror Yellow that cures for 15-20min at 375-385°.
Heat oven to 15-20° higher than your curing temperature, as there will be a lot of heat loss when you open the oven to place your part in it (Just make sure you remember to turn it down to the correct temperature while the piece is curing).
The oven can take up to an hour to heat up, you can prepare the rest of your materials while waiting.
Step 2: Setup
To set up powder gun:
01. Attach Air Hose
02. Plug in Gun
03. Attach Ground to Rack
04. Clean/Attach Powder Receptacle
05. Attach Powder Feed Line to the Gun
06. Turn on the ventilation to the booth.
See Powder Coating Basics for more detailed instructions
Step 3: Prepare Bottle
01. ALUMINUM: Roll the aluminum into a rod thin enough to fit though the bottle neck, and long enough to stick out of the bottle about an inch.
02. (OPTIONAL) SANDBLASTING: Normally, sand blasting is used to prepare the surface of the material for powder coating. In this case, I chose not to sandblast because I wanted a gradient on the shiny glass. This way is a bit trickier, but can be done.
03. HANGER: To make the hanger, bend the wire into an S shape. This should be long enough to hold onto easily without touching the piece. Poke the lower portion of the hanger into the bottle, and bend the top outward. Then push the lower portion of the hanger down into the bottle, so that when the wire is pulled up on, it will catch on the mouth of the bottle. The fit should be tight enough that your piece will not fall when hung.
04: CLEAN BOTTLE Spray the bottle with simple green, and scrub to remove all coatings or oils. Then rinse the outside of the bottle with warm water, careful not to get any water inside.
05. DRY: Dry your bottle by hanging in the oven while you set up the power gun. I like to wait until the oven is at temperature to remove the bottle, because once you remove the bottle you need to work very quickly to coat the bottle. Heat is the most important element in coating glass.
Step 4: Powder Coating
Remove your bottle from the oven, and hang it on the powder coating rack. Holding the gun about 6" from the bottle, begin to spray in sweeping motions. To achieve the gradient, angle the gun down slightly so that the overspray doesn't stick to the higher parts of the bottle. You'll need to rotate the bottle to spray the backside of it. For a more intense gradient, apply a second coat to the lower portion of the bottle. The aluminum inside the bottle will help the powder stick to the glass, but if the glass still rejects the powder, turn the PSI on the gun down.
Place the bottle back in the oven. Don't start timing until the oven reaches the proper temperature.
When the time is up, remove the bottle from the oven and hang it on the rack, waiting about 15-30min for it to cool.
Remove the aluminum rod and wire from the bottle (you may have to pull hard to remove the wire, but it should come out as long as the wire is pliable enough)