I have 2 steel parts which were both powder coated in a polyester powder coat, however one of them does not perform exactly as I would expect it in my unusual use case which depends on temperature. I suspect this is because the well-performing one contains epoxy - but I am not sure. I would like to sort of narrow down my options for ordering new parts.

Both parts look virtually identical, and unfortunately I only have 1 of the well performing part, which I also need to use constantly.

Is there a reasonably accessible (common household/industrial chemicals or tools) way to detect if either of the powder coats contains epoxy, without it being triggered by polyester, either chemical or otherwise?

From what I gathered, acetone would dissolve both of them, so that likely won't yield any results without some detailed analysis.

  • $\begingroup$ Can you scrap a little the one that is working better? The idea is to take a sample and run some analysis. The most simple one will be an FTIR. Here is an example. $\endgroup$
    – Guille
    Commented Nov 25, 2022 at 7:45

1 Answer 1


You should mix both in some acidified ethanol mixture. Acid can be muriatic acid. Water and dilute acid will hydrolyze epoxy to a diol but won't be able to break ester. This diol when reacted with periodic acid will release a ketone which you can then apply a tollen's test for.


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