Need information on how to repair the damaged seal coat in our gunite pool. We have a saucer size section of the final seal coat (looks like egg shell thickness) that cracked & peeled off exposing the white plaster under it. We have easy access because it's on top of the first step into the pool, therefore we can lower the water easily to have a 'dry repair', if necessary. Any product & instructions would be appreciated....ggo 36