Now the wallpapers dry I am sealing it so it will be washable, quite important in a food trailer. I am using watered down PVA glue and getting a couple of coats on a day.  DISCLAIMER: DO NOT COPY THIS METHOD as there is still more to the story.

We’ve painted the whole outside of the trailer with red oxide which is really for painting metal (tanks are painted with it because it’s so strong) so were hoping it gives a strong, waterproof coat to our fibreglass too.  I hope it’s a decision that don’t backfire cos it won’t want to come off if not. It may not be beautiful yet but a bit more subtle maybe.