Painting radiators- bubbling paint

getting cold

While doing a renovation project in my home I decided to farm out the painting of my radiators to a professional painter. I wanted them sprayed to match the colours of the rooms. The radiators came back the first time a year ago. I reconnected them, turned on the heat and the paint started bubbling like crazy. They looked like they had a bad case of the chicken pox.I assumed this was due to lack of surface preparation which the painter denied. He did agree to take them back and redo them. I just got them back and have the same problem on 2 of the three. The one that is now fine is a different colour than the other two which are identical.The painter is stumped and has offered a refund. I now wonder if perhaps the paint was diluted too much when he put it in the sprayer. I am going to strip them and redo them myself. I have heard that it is not neccessary to use high heat paint and have sprayed a few others in my home with regular interior paint.Does anyone have any radiator painting advice?

Big Ed_4

Powder Coating.....

.....is the way to go for me.

Brad White_200

Solvent

Hi Sandra

My first inclination is that I suspect excess solvent or binder. Solvent, be it mineral spirits or water or binder in the form of resins often is behind this. It boils essentially to vapor under the outer paint film and breaks out. Now, you really do not need to use high temperature paint, but the paint does have to cure for a good while before firing up the system.

Now, if it has been a year since it was coated, surface preparation comes to mind.

Something else, just a theory, but I wonder if steam might be coming out the pores of the metal itself? Just a hunch, apropos of nothing, but it strikes me the way vapor (OK vapour to you) , migrates thought a house wall to blister paint. That it blisters right down to the base has me thinking this. I have never heard or thought of it before, but molecules are tiny things.. really getting out there in mentioning this.

Powder coating is indeed one of the best things going. I had heard of it for a few years (outside of normal factory-industry applications) and could not believe how nice the finish is applied to a radiator. Easy to dust too, you really actually want to. Nothing clings to the finish, it is that smooth.