2 powder coats: Color then clear

[robmdall]

I worked in Automotive Coatings for 20 years, both Liquid and Powder. I would look towards a little better gun then the Harbor Freight job. A coworker of mine used the Eastwood HotCoat (Google it) with good results. A few things you should look out for (no specific order).

Powder is a nuisance dust, wear a dust mask.

Ground the piece you are coating, can't say that enough! Ground, Ground, Ground! A precision coating will not be made with a bad ground.

Also, if re-coating use the same area of the part for grounding. Lower the KV's and back off on the flow of the powder.

Inner-coat adhesion is accomplished by following all of the rules.

The key to curing any coating is not simply temp, it is a combination of time and temp. May require sampling to achieve the best results with your equipment. I.E. don't cure at 600 degrees for a minute, maybe cure at 380 degrees for 15 minutes. (IR cure is the way to go).

If the powdered part looks bad in dry form, curing it is not going to make it go away, Blow it off and coat it again.

Once applied properly, I have seen parts sit for a few days before being cured with no lose in physical properties, No huge rush to cure like a wet paint.

Save some bucks $$$ The beauty of powder is that your over spray is reclaimable unlike liquid coatings. Keep your work area (booth) clean so you can reclaim the powder. Store reclaim and virgin in separate containers and only mix in the fluidizing hopper during application. Powder particle size breaks down during application, the fines (reclaimed powder) will not act the same as virgin powder. Fluidizing issues, charging issues, hiding, etc.

Purchase a gun that fluidizes the power correctly. That is one of the reasons I don't think the HF gun would work all that good, with the hopper on top. Remember, clumpy powder sprays like a lumpy liquid paint.

Store powder is a cool dry area. Powder storage and heat are a horrible mix.

Preheat the part being coated - 80~90 degrees is good. (while re-coating also).

A CLEAN Substrate is the key to any type of coating - garbage in - garbage out!  Probably the number one rule in coating, nothing sticks to dirt or finger oils, etc.

Any questions just ask. I am sure the above is a ramble of words, however it is based on experience.

Rob

[tiges_ tendres]

Most hobby guns do have the hopper on top.  The Eastwood gun is the exception for a sub $100 purchase. I decided to go with the harbor freight  gun because I liked that it was a one handed operation.  The charging is done with a foot pedal, rather than a button you hold in your hand.  This works better for me as I have a tiny space to work in which means I often need my other hand to move the part around to get full coverage.

One other piece of advice I'd offer, when you see a time and temperature listing for a powder, this is not the oven temperature and the amount of time you should leave it in, it's the temperature the metal being coated needs to be at and the time you need to leave it in the oven at that metal temperature.  You cant really guess at this, but you can get a very cheap infrared thermometer at HF
http://www.harborfreight.com/cpi/ctaf/displayitem.taf?Itemnumber=93984