I think one of the main problems of paint chipping on machinery is because it has not had a good bonding undercoat applied. If you look at a lot of paint chips they are down to the metal. Meaning they have not been prepared or had the undercoat keyed properly. Someone will be along shortly to give you a list of the best paints to use.

Steve.

+1 for Tractol. High pigment content so covers well, and tough as old boots. Good for brushing because it dries slowly, which means there is no problem keeping a wet edge, and brush marks tend to flow out leaving a very good finish. Need to be careful to avoid dust though. When fully cured it can be cut back and polished to a very high gloss. Smith and Allen keep a wide range of colours, and I think they also supply it in spray cans.

I painted my old Boxford lathe with one-pot epoxy ultra blue. It is Australian Wattyl Rustkill. Nowhere near the original color but I'm happy.

Someone else said that I had chosen the idea type of paint. as good as two pot. I left town for a year and when I came back it was hard asa rock.