Hello, Briefly: is there a way to obtain a small amount of plasterboard tiling primer without paying for a full pack? In more detail: I noticed that a tile on our shower wall was no longer flush with the rest of the tiles. I prized it up, it came off easily. Things don't look too bad: the paper was rotten but the plasterboard seems fairly intact. I've gathered I need to dry it thoroughly, prime it, dry it, then reattach the tile. I've got some adhesive and grout from a friend, but he didn't have any primer. I know I can't use PVA in the vicinity of the shower, and correct me if I'm wrong but I believe any water based primers are also inappropriate and it needs to be something like aquaseal - but that costs £10 per bottle and I don't fancy spending that to reattach one tile. Any suggestions where to get a small amount? Do any builders merchants sell it by weight where you can come with your own container? Do any manufacturers have anything like sample sachets?