Smooth with rough patches.
by Steve M
Hi, I am getting the wall really flat and smooth. The walls look great whilst plaster is still setting and even feels like glass. However, once it has dried totally I find the wall is really smooth then suddenly rough in patches, like sand paper.
Do you know what is causing this?
Sorry for the delay - it sounds like a lack of pressure in the earlier stages of troweling up. If you push really firmly then your trowel will be in contact with all parts of the wall - by pushing the highs into the lows. If you don't push hard enough then your trowel will just be in contact with the highs.
So plenty of pressure but at the correct angle - otherwise you'll scrape plaster off. As a rough guide the leading edge of your trowel will be about 15mm off the wall. This gap can be increased as the plaster firms up.