I am repairing several plaster walls in my home due copper re-piping. The original plaster walls used a 3/8" drywall backing with random =BE" diameter holes so that what looks like stucco could bond. Then the finish coats of plaster were then applied to what looks like stucco. This system resulted in a =BE" thick plaster / stucco / wall. I have repaired some walls that were not visible by installing =BD" and =BC" drywall and then taping and mudding. However, the finished product does not look as good as the plaster. I want to repair the walls with plaster on the walls that are visible. My intention is to duplicate the same system that was originally used. However, I may use =BD" dry wall to start the process. I have never done plaster but have plenty of drywall experience.
My question is this what do I use the build up the wall. Are my suspensions confirmed in that it is stucco that is bonded to the original drywall backing? If not what do I use the scratch coat? After reading several articles on how to plaster they state to use a scratch coat, a brown coat and then a finish coat (skim coat). I want to build the wall back up to match the others then using a bonding agent will apply a brown coat and a finish coat to the entire wall. I just do not know what material to use for the scratch coat. It does not seem right that I would use finishing plaster for the scratch coat. =20
Thanks in Advance, =20 Jim