Problems when applying epoxy floor coating

With most of the problems when applying epoxy floor coating there is no easy fix or easy solution .The best is laying another epoxy floor coat ?!
If problems develop due to user error, poor surface preparation, or a surface not suitable for coating that is not something the manufacturer can control or take responsibility for. The risks certainly are in the user's court even for things that might be completely outside his or her control.
Adhesion issues :
The worst problem you can have when laying epoxy floor is adhesion failure.
We discussed many options on this topic on the previous page.
See here: Why epoxy floor coating fail

OTHER PROBLEMS:
Air bubbles-Air bubbles in a thick floor epoxy will cause round bubbles and, more commonly, with razor sharp edges. Bubbles can happen from these three reasons,
1. Air trapped in the epoxy because of fast mixing of epoxy resins
2. From roller if using a foam roller or thick nap roller.
3. 90% of the time it is OUT GASSING from the cement.
Pinholes-When protecting concrete with epoxy floor coatings, or any surface coating, pinholes through the coating sometimes form. They have two possible causes.
1. Pinholes can be caused by air trapped below the coating in tiny surface voids.
2. The air expands outward before the coating has cured due to solar heating.
Fisheyes -Fisheying occurs due to surface tension differences between the coating and a grease or silicon (sometimes even dust) particle. Simply put, the coating pulls away from the contaminant, leaving a tiny crater like structure in the coating. This crater is not connected to a subsurface air filled space. Fisheying is almost always a surface preparation problem.
Induction time-Some epoxies (and most 2 part polyurethane's) have an induction time associated with them. This means after mixing the 2 parts you need to let the mixture sit for some period of time before using it. If you skip this step, the epoxy may not get hard and/or the color may be off.
Color differences-Like with all other paints, there can be color differences between batches of epoxy. If you order your epoxy in small units, it is very possible that the cans may come from different production batches. Also pigments can settle to the bottom of the cans and with thick epoxies that are harder to mix you might get color differences just because you didn't 're-mix' the epoxy's pigments in the cans equally well. Epoxies all yellow, even the pigmented ones. Epoxy that has been exposed to sunlight will become a different color than the same epoxy, from the same batch, still in the can.
Epoxy stays tacky-If it is just tacky in spots but hard in other places, this is poor mixing. If the entire surface is tacky, two parts are not mix in the correct ratio. The epoxy may also be tacky if is not given it enough time to get hard. Cure time is temperature dependent. Cold weather could slow the cure rate. Curing will continue when the temperatures warm back up. Still, the epoxy should be hard within a few days at most.

More about this topic you can find in "The Best Web Epoxy Links" eBook.