Problem Solving Forum
March 5 - March 11, 2017
What is best way to remedy over-thickness of a topcoat after it has dried and cured?
Selected Answers
From
Jaime Molina of Primary Materials Inc. on
March 8, 2017:
Over-thickness of the finished coat is a bad corne ...read more
Over-thickness of the finished coat is a bad corner to paint yourself into. Correcting it is expensive and time-consuming, and the results are less than certain.
If the problem is bubbles created by out-gassing, you can grind and reapply the topcoat. If the situation simply requires that the thickness be reduced, then I can think of only two alternatives to address this.
First is mechanical grinding. All resins are hard and it will take time and effort to shave off just a mil. If the topcoat is polyurea, it will be even harder.
Chemical removal is a second option, but that has the drawback that you could remove part of the first coat, the coat that penetrates the concrete, seals out moisture and bind the coat to the floor. In this approach you should assume that the integrity of the first coat will be damaged and recoat accordingly. A recoat with a thinned epoxy might get the correct penetration while keeping thickness down.
A practical approach to consider is chemical removal followed by mechanical grinding.
In any and all cases, it will be challenging to remove only the excess.