So you’ve done all the prep work right you mixed and applied the epoxy per the instructions and everything looked great when you were done! Then the next morning when you come back to apply the topcoat you discover for some reasons you have the following issue.
The above two images are of small epoxy spots that didn’t harden. This happens when not enough Part B was mixed into a batch or a batch was not mixed good enough and some Part A didn’t mix with enough part B. If this happens to you don’t feel bad it happens to our guys sometimes when they get in a hurry to finish a job. The good news is this is very easy to fix. Sometimes if you have some part B leftover you can rub some into the spot and it will hardened in 6-8 hrs. If that doesn’t work simply scrape up the soft epoxy, wipe down the area with Xylene(Home Depot) as best you can. You don’t have to get down to bare concrete, just scrape and wipe off as much of the epoxy as you can and then reapply some new epoxy to that area. We would also lightly sand the perimeter of the epoxy on the floor so that you can lightly overlap the new epoxy onto the cured epoxy.
Also if this happens we want you to apply the topcoat to the rest of the floor, do not wait because of this minor issue. You will apply the topcoat to the new epoxy after it dries and again you will lightly sand the perimeter of the topcoat on the floor and lightly overlap it with the new coat of topcoat. Problem solved. When this happens it’s a concern but don’t panic. The coating is not defective. The epoxy can’t cure in some places and not others. It’s either all bad or not bad at all.It is extremely rare that you would ever get a bad set of epoxy that won’t cure. We test every batch of epoxy for curing, adhesion and hardness before it goes into inventory.
The best way to avoid this from happening is to have one person do all the mixing and use clear calibrated mixing containers to measure out the part A and part B amounts accurately. These containers can be bought at Home Depot and such for 99 cents. Get the 100+ ounce size containers. With only one person mixing and using measuring containers you’ll never run into this problem. The only other way this can happen is if you’re doing the floor during the colder months and you have a cold spot in the floor usually by a door or wall. Putting some heat in that area will solve the problem most times, if not follow the above procedure. Remembering to apply the topcoat right away but not on any epoxy that is not rock hard. If you can make an indent in the epoxy with your finger nail it means the epoxy isn’t fully cured.