Every now and then, different practical examples with our coatings come back to us. Thus, sometimes things go wrong and we try to find the solution together with our customers.
In this case, a customer wanted to coat his steel pool. His process:
- Surface cleaned with diluted detergent
- Rust removed with a grinder, wire brush and sander.
- Cleaned again with the diluted detergent
- EPX Primer applied
- 2 coats of X2+ Colourcoat applied
- 1 coat of AG2 Topcoating applied
- After 12 days of curing filled with water
Problem
After a week of operation with water, several pieces of coating came off. Especially at points where mechanical pressure was applied.
Cause
As it turned out, the fault in this case was in the substrate preparation process. By cleaning the substrate a second time after the sanding process, oxidation (rust) took place on the bare steel substrate. This can occur very quickly when you wet bare steel. The EPX Primer adheres worse to already present rust since it has no rust dissolving ability.
Solution
Unfortunately, it was too late for the customer in question. From now on, the substrate should be primed immediately (read: a few minutes) after sanding. Despite the fact that EPX Primer is water-based, it is extremely suitable for applying to bare steel objects without rust formation. On already present rust formation, it does not go well.