Paint adhesion...??

David, I'm guessing that, as a guitar builder, you know how to prepare a surface for a coating. Apparently, many do not, or they do but they get careless. And to most people, paint is something they take for granted—all paints perform exactly alike, regardless of anything else, right?

Um, no.

Enamels and traditional lacquers have been around for so long that they are very well developed technologies—almost all the bugs that can arise are well known, as are the fixes. Acrylics are in their early childhood, by comparison. And they don't work the same way as enamels.

As for the bare bones of your question: poor paint adhesion is due to one or more of the following:

1. Poorly formulated paint. (Not very common. Most modern model paints are at least adequately formulated. YMMV)
2. Poor surface preparation. (Extremely common.)
3. Using the wrong paint for the surface. (Common, but not frequent, at least in modeling.)
4. Deteriorated paint. It does have a shelf life.
5. Poor application. (Common.)
6. Poor application conditions. (Common, but not frequent.)
7. I know I've missed something………

Bgrigg wrote:

7. Insufficient time to allow the paint to fully cure (unless you are lumping this in with application?).

I was, but it probably deserves separate mention. OTOH, for some paints, waiting too long before overcoating causes problems, so maybe we should leave it lumped. 

Triarius and Bgrigg   thanks for the replies and advice.....

I guess I wasn't clear......How do you know if you don't have good adhesion? I used to figure....if the paint isn't too heavy....details show through....all was good.

Nam 

Paint adhesion is the ability of the paint to stay where you've painted it. Easily scratched paint, or paint that pulls off with masking tape is an indication of poor adhesion. Sadly the only way to find out is to discover it. Prevention is the only cure.

Proper cleaning of the styrene (and hands!) before painting, priming whenever necessary, ensuring that the paint you used is properly mixed and thinned with the appropriate thinner, and making sure that the paint is dried (or cured in the case of acrylics) will prevent problems, unless the paint is past it's due date or somehow become unstable.

If you've never experienced it, then you're doing everything right! I wish I was so lucky!

Ahhhhh!...........Okay....now I get it.!!

My bad.......in the old days (creak,creak)....no internet, no cells....we just said.....

"The s**t peeled off!"

 At least I know what page I'm on.....Thanks guys!

Nam 

namrednef wrote:

"The s**t peeled off!"

Precisely, I sure could have used a lot less keystrokes, eh?