Can gunnite be applied by hand on a previously built swimming pool?

Answer 1

Gunite is a sand and cement mix with little or no gravel and is pressure shot into place with a compressor supplying air pressure. So the gunite process can not be done by hand, but you can add a mixture of patch material that is made by a manufacturer to meet strength requirements. Most building supplies or home improvement stores carry cement mixes that will work. I don't know the exact problem, but generally clean the area that needs the additional gunite with a power washer and then lightly etch with muriatic acid, (available at hardware or home improvement stores). This will give you a surface that should bond to the new cement patch material. You want to build the material in several coats if it is going to be thick as one thick coat is likely to crack. Leave each coat with a rough finish to help bonding and finish with the pool finish, usually a plaster with marble dust mixture, to seal and maintain color continuity.