There was a Scottish painter named Smokey Macgregor who was very interested in making a penny where he could, so he often thinned down his paint to make it go a wee bit further.
As it happened, he got away with this for some time, but eventually the Baptist Church decided to do a big restoration job on the outside of one of their biggest buildings. Smokey put in a bid and, because his price was so low, he got the job.
So, he set about erecting the scaffolding and setting up the planks, and buying the paint and yes, I am sorry to say, thinning it down with turpentine.
Well, Smokey was up on the scaffolding, painting away, the job nearly completed, when suddenly there was a horrendous clap of thunder, the sky opened, and the rain poured down washing the thinned paint from all over the church and knocking Smokey clear off the scaffold to land on the lawn among the gravestones, surrounded by telltale puddles of the thinned and useless paint.
And from the thunder, a mighty voice spoke:
“Repaint! And thin no more!”