Instructables

Why does spray paint sometimes come up off the painted surface when the surface has been primed?

I was making something to hang up on my wall, a thin metal logo of the skullcandy skull. the peice of metal was free of rust. So I primed the surface and let it dry. spray painted it and then the paint was going crusty-ish and was peeling of the metal.

I don't have a picture now, but i will upload a picture later.

poofrabbit2 years ago
Krylon makes a great spray paint for metal surfaces. I would actually remove the primer and sand the metal. I would then to several coats of a krylon paint and build up the layers and color. Can't wait to see the pictures I might be able to give you a better idea.
Its all great advice and right on the money,just as an addendum you may want to consider giving your freshly primed surface a quick sand with a 1200+grit and a wipe with a tack cloth before final paint.
Good luck

Tragic
canucksgirl2 years ago
Was the metal aluminum?

Aluminum (as well as a few other types of metal) are very finicky when it comes to painting, so you MUST use the correct type of primer and paint. If you read the labels, you'll see one that is specifically formulated for use with aluminum (or the type of metal you have).
Burf2 years ago
If it is a wrinkled, blistered and cracked look, the paint and primer are incompatible.
There are four basic kinds of spray paint, polyurethane, enamel, acrylic and another that is formulated specifically for plastic. Read the can labels and make sure that the primer and top coat you use are approved for use together and be sure the primer has completely dried before applying the top coat.
Do that, and it should eliminate the wrinkling problem.
rickharris2 years ago
Paint sticks to whatever you paint because of tiny surface imperfections, this allow the paint to grab the surface.

If the surface is too smooth then there is little other than the skin strength of the paint to hold it in place i.e. it isn't actually stuck to the surface.

Spray paint is a VERY thin layer and so has little skin strength and so if not stuck to the surface it cracks and peels off.

To get it to stick:

1. the paint and the surface need to be compatible - example you can't paint greasy things because grease and paint are incompatible.

2. the surface need to be keyed - it needs a rub with some very fine glass paper or wire wool to scratch the surface to allow the paint to stick.