I have thinning plaster on the walls. I have several home projects this summer and just can't afford the $3000+ for a replaster. I have partially drained my pool and pressure washed the thin areas where algae are really digging in. I have a few spots where the gunite is showing through. I have a product from the pool shop called Pool Patch (portland cement with dry polymers). I am still not sure how to get started covering these bare spots up. Any ideas?????