Good powder coating does not exist in a vacuum. It’s not enough to simply purchase the best powder on the market, and ask the most skilled powder coater in the world to apply it – not if you want your coating to last.
High-quality powder and skilled application are just two of several requirements that must be met in order for you to find long-term satisfaction with your coating.
Another (often overlooked) requirement is proper pretreatment. You can skip pretreatment and wind up with a beautiful coating…but you can’t skip pretreatment and expect that beautiful coating to last.
Thankfully, good pretreatment is simple to quantify. It relies on three pillars:
If you’re in the market for powder coating services, ask your shop how much time it spends on the pretreatment process. If they give you a blank stare, that’s a bad sign. Proper pretreatment takes longer than simply rubbing your oily part with a damp rag – if the shop doesn’t have a time-consuming pretreatment process in place, your money is better spent elsewhere.
Next, ask your provider about the pretreatment temperature. If they aren’t using a little bit of heat, you can bet that the oils in your part are not being properly washed off. Anyone who has done dishes in cold water can attest: deep-cleaning of anything (particularly oily surfaces) requires heat.
Finally, pay attention to concentration. This is a harder subject for customers to broach with their shops: most powder coating professionals (myself included) use a proprietary blend of chemicals that we’ve developed, tested, and proven effective with our city’s water supply and environmental conditions. We’re not likely to divulge this hard-won recipe with our customers, nor should we. However, if you were to take a tour of the powder coating shop, you should expect to smell a strong chemical odor near the wash bay. If there’s no chemical smell, it’s likely that the pretreatment is too diluted to be effective. On the other hand, if the chemical smell is overpowering, it’s likely that the shop is using chemicals in too-strong concentrations.
Shopping for high-quality powder coating means shopping for high-quality pretreatment. Without it, your coating is bound to let you down.