I’ve blogged extensively about Kaser’s pretreatment processes and the chemicals we use on steel and aluminum. Now, it’s time to address the ground rules of the wash bay.
While the chemicals we use are at relatively low concentrations (meaning they won’t necessarily burn your skin on impact), don’t be fooled – consistent exposure over hours, days, and years will harm your body. I recommend wearing safety glasses, a face shield, a half face respirator, a rain coat, chemical-resistant gloves, rain pants, and rubber boots. The only moisture on the operator’s body should be sweat.
Beware of alkaline cleaner.
Alkaline cleaner is a powerful tool for removing grease and oil. Unfortunately, if not properly rinsed off, it can wreak major havoc on powder coating adhesion. Proceed with caution. When possible (meaning if parts aren’t too oily), I skip the alkaline stage altogether. It lowers the risk of cured powder coating falling off in sheets later on.
Use purified water for your final rinse.
City water is full of “solids” – minerals, contaminants, and foreign bodies that could interfere with the powder coating process. Use reverse osmosis or deionized water for your final rinse, to ensure you’re not dirtying your clean parts all over again.
Don’t let wet metal sit for too long.
Pretreatment helps ward off corrosion. However, it doesn’t alter the laws of chemistry: steel + moisture = rust. After your final rinse, use clean, compressed air to blow off your parts, focusing on any corners or dips where water might have pooled. Then dry your parts in an oven, and powder coat them as soon as you can.
Mind your ears.
It’s no surprise that pretreatment chemicals pose a risk to your eyes, skin, and mucous membranes – but keep in mind that compressed air is louder than you realize, and could cause permanent hearing loss very quickly. Wear earplugs anytime you’re blowing off.
Finally, I wouldn’t be true to myself if I didn’t end a pretreatment blog with the most important reminders of all:
- Good pretreatment takes time. Don’t cut corners.
- Cold water won’t clean parts thoroughly enough, so mind your temperature.
- Even the best chemicals won’t work if they’re in the wrong concentration.