I've done entire houses with a hopper system and they all turned out sharp.I scratched the wall up with a good course grain sand paper and went for it .
I'm reworking the bathroon in a trailer I'm renting. The walls are covered with FRP and I want to make all the seams and extra trim pieces go away by putting bullnose on outside corners and patching gaps in inside corners and seams. Sparying the whole room with an orange peel will be a nice way to blend all the patchwork together. My question is how do I get the texture/mud to bond/adhere to the FRP.
How long has the texture lasted on top of your FRP?
I would not do that. But if you want to try it, I would think you need lightly scuff the surface to remove any contaminants and give it some tooth. I still wonder how well the bond will stand up to bangs and bumps.
The house is on a foundation. By bangs and bumps did you mean from the road or from hitting the wall itself?
Yes I meant someone or something banging the wall. The FRP may have some give, and such flexing would be hard on the bond of the texture.