The last thing you want to do is chase down a bunch of pin holes and bubbles after the new epoxy coating has been applied. Small air pockets can be trapped under the newly applied coating that can expand as the coating heats up and starts to cure. This can lead to bubbles or in some case pin holes in the surface of the coating where air managed to escape.
There are some steps that you can take to minimize this issue before it happens. Making sure everything is properly cleaned and then priming the affected area with a small thinned mixture of Pond Shield will normally alleviate this problem. Apply the primer mixture with a small brush to stipple the coating into the holes or a roller if the holes are not too deep. Once the material begins to tack up, the normal process of coating can take place.
Should you find pin holes or bubbles after coating, these areas can be repaired using the same method described.