I needed to paint house numbers on my wheelie bin and I didn't want to spend money on that. So I just painted nice white squares with... two coats of interior wood undercoat/primer + one coat of interior wood paint. Worse, I exposed that to the rain before it was completely dry and the rain ruined everything.
After cleaning paint-run I'm wondering: is there a simple way to keep my nice squares and just make then somehow rainproof?
Also I'd like to draw house numbers on them, can I just use a dark marker pen?