Finishing of control panels: Q&A's re. epoxy, powder coating, recoatable enamel

A. You can get all the answers in the ISI standards, or ASTM standards. There are reputed labs who do this testing on commercial basis and give you the results.

However, it is tough to say the appropriate thickness for Indian conditions as there are so many factors into play.

Regards,

A. Hi cousin Atul. Each of those questions is excellent, but in truth even a 5-day course might not answer them all. If there is urgency to these questions, I think your company might retain an epoxy painting consultant who could tie it all together for you in a day or two, leaving you with a process specification and testing regimen. Otherwise each is the subject of one or more threads on this site.

Will the epoxy be applied as 2-k wet paints, or as a powder coating? This will impact the answer to "ideal coating thickness". Best of luck.

Regards,

A. If the paint is coming off in sheets if it gets scratched, you could have a pretreatment or under-cure problem. I'm thinking under-cure since someone told you to try heating the parts before painting them. The information they gave you is sort of correct: if you paint a hot part the paint starts to gel as you are applying it, but it can become difficult to tell when to stop painting. That doesn't mean you are applying a thinner coat of paint, it just means that you have to apply it very quickly and be careful not to overpaint. If under-cure is really the problem, I would suggest running a tracker through you're oven and find out why it isn't curing the parts properly. If this doesn't have anything to do with what you are asking, I take it all back.

A. Don't worry about the descriptions we use in coatings ... powder coating, electrodeposition, electrostatic wet spray, spray gun applied, dipping, brushing ... the list goes on and on. They tend to describe the method or carrier that is used to transport the base resin from the container to the object to be coated surface, i.e., air, electrics, solvents or water. What you should be aware of is the resin system being used to make that coating. For your industry you are correct: powder coating is now the norm. Polyester for external work, epoxy for chemical environments. If the items are destined for internal locations with no atmospheric problems then epoxy polyester should be adequate.

A. Hi Ravi. Powder coating is already widely used on control panels and similar surfaces, and I think the very general answer is that powder coating continues to increase in popularity. The ideal finish, if affordable, is probably zinc phosphate pretreatment, followed by electrophoretic priming, followed by powder coating. Good luck.

Regards,