Fuzzy spots after priming

[renini]

Hi everyone, first time build here (p bass with 32" neck).

I've just sprayed duplicolor primer on the body, and have been left with some fuzzy spots - particularly on the back and front.
The sides seems to be mostly smooth. Are these dust, raised fibres or something else?

Thanks in advance

[fender3x]

It doesn't look like dust to me.

To me, the most likely culprit is little balls of paint. There is more than one way that you can get this while spraying with rattle cans:

1) Spraying from too far away
2) Spraying in a climate with very low humidity, particularly when it is hot
3) Spraying with a bad nozzle.

In the #1 and #2 paint dries before it hits the surface of the guitar. When that happens you get what looks like tiny pebbles on the surface of the paint. You could try to spray a little closer to the surface and see if that helps.

A bad or partially blocked nozzle can also atomize weirdly, although in my experience #3 is more likely to form blots than pebbles.

As you suggest, fibers sticking up is another possibility with a few different causes:

4) It could be that painting raised the grain. Not sure what sort of Duplicolor you are using but they make some acrylic (water based) paints. When a water based product hits smoothly sanded surfaces, particularly in open grain woods, it can make the grain stand up. On new wood the solution to this is to (a) sand until the surface is smooth, then (b) dampen the wood and let it dry completely. This will make the grain stand up so that you can sand it back down. Alternatively you can use a sanding sealer or shellac before using the water based product, so that the water can't penetrate the grain and make it stand up.

Since you have already started painting you don't need to dampen the wood or seal it. The paint will do that. Once it is dry enough to sand you can just sand flat and repaint.

5) it is also possible that there were some places not well enough sanded, but I don't think that's it.

My money is on #1, #2...with an outside possibility of #4.

If #1 or #2 you can wait until it's dry enough to sand, and just gently flatten the little paint balls. The most important thing is not to do it too soon, which could make a gooey mess.

I used Duplicolor on my first build and had a terrible experience. My climate tends to be hot and humid which it did not like, so I haven't returned to it. That said, most users here who have used duplicolor have gotten good results.

FWIW My go-to rattle can paint is MTN 94 which is an "artist spray paint." It's about the same price as Duplicolor, but I find it very forgiving. Even if a get the occasional pebbles or blotch, I just keep going and trust that it will sand out. It also works well in my climate, and I can get extra nozzles, so that if one fails I just change it out. You get it at art material stores. It's a European brand, but I know it is sold in Australia and the US as well.