Painting transformers on tube amps

Any layer of paint is, in a small way, also a layer of insulation. So, the flatter the better for heat radiation. A rough surface radiates heat much better than a shiny surface. Agreed that properly operating transformers don't see much heat, but they will see less if painted flat.

If one works outside in warm, sunny weather, and lets the transformer dry for several hours in the hot sun, a quality flat will be as durable as a quality gloss. Otherwise, an hour in a 150F oven after drying. But the key is prep. If I am going to paint a transformer, I will clean it first with an ammonia-based cleaner on a rag, then I use a soft *BRASS* brush on any rust, then clean with acetone on a rag (not poured onto the transformer itself) to remove any loose paint, grease or other residue, as well as break the surface of the existing paint. Then a green scrubbie dry on the rest of the transformer to rough the broken surface. THEN paint it, spray or brush. I use a flat paint, they look almost new. If I could somehow fake the numbers easily, they would look new....

Krylon is good stuff. I often use the term "accept no substitutes" together with Krylon products.

I learned the barbecue paint lesson the hard way. Not durable as Bob says. I repeatedly found myself touching up chips and other marks that would seemingly appear out of nowhere whenever I set them down. Finally I resorted to applying a clear topcoat to protect the paint. Look good now, but taking a lot of effort to get there.

My first amp I'm calling my "rookie mistakes" amp. I'll be doing a few things differently when I get to the second one!