confused

I'm totally confused by what I witnessed last night when skimming one of my walls. I am laying onto old sand and cement render, I made sure to do two coats of PVA to reduce the suction as much as possible. When I started applying my first coat I suddenly had what looked like random patches of...

Hi, I've been looking all over the web to understand the differences between these tools and when to use them. As far as I can see they are both long, straight and flat blades. The difference seems to be that the Darby is made of metal (aluminium) and the Speedskim is made from plastic...

I just moved into a house that was built in the 1960s and one of the rooms has messed up plaster on it so i want it removed and new stuff on the bricks are red on the outside of the house. I think they are clay but idk. What surface do you think I will find once the plaster is knocked off and...