My last couple of posts have been about hanging this mural in a garage.
http://muralsuperstore.com/catalog/tobago_sunset_pr98097_5221594.htm
Before I could hang the new mural, I had to remove the old one.
Photo murals are generally hung with a cellulose paste, which is about the lightest paste you can get. And with the hot humid conditions of a west-facing garage in Houston, you could assume there would be some interaction between the paste and the climate, over time. Indeed, the 8 panels of the old mural came off easily, by simply pulling up one corner and then the whole thing came off in one sheet.
This left behind a loose, gritty, sandy substance that was probably paste residue. BAD, because the new mural would never stick to an unstable surface like that. The loose sandy parts would simply seperate from the wall and the new mural would fall to the floor.
So I sanded the wall to remove all the loose old adhesive. Then I went back and wiped it with a damp sponge, to be sure there was no sand or powdery residue left. Once that was dry, I primed the wall, to further ensure a stable surface, and to seal any paste residue that could bleed through the new mural.
Then I was finally able to hang the new mural!