What happens if you paint without primer?

Question

I'm painting a guitar body

(its wood)

Answer 1

The paint will be prone to cracking and flaking.

Answer 2

I have painted both ways. When painting on 'new' walls--like ones never painted or only having 'builders grade paint (ie--very thin paint), the paint will stick better if you use primer. Also, when using a very deep color (like red) it is useful to prime even formerly painted walls so that you have more even coverage.
Another consideration is the makeup of the paint you'll be using. If you are painting a latex paint over an enamel paint, it will peel (like a previous answerer noted). I always try to determine how old the previous paint is--if it's been around for awhile or stained then I would definitely use primer. If the paint is from a builder (as in new construction) or you know that it was painted within the last 10 years you've got a pretty good bet that the paint is latex and you won't have peeling issues.
Painting on wood is trickier. I would ask the paint vendor for help choosing the best product to paint wooden trim.

Answer 3

Depends on what you're painting.

If you're painting over drywall or spackle, the primer soaks into the surface and the paint coat adheres better. Without the primer, the paint will be subject to coming off in strips (especially if you put painters tape on it to then do trim or something).

If you're painting a darker painted surface, the primer covers that color and prevents the dark paint from leeching up through the paint coat. Otherwise, you may need a coupla-few coats of paint on an unprimered surface to hide the old, darker paint.

If you're painting a metal surface and don't use a primer specifically for metal surfaces, the paint will not adhere to the metal and it will fall off when it's dry.

And, if you're painting a bare wood surface without primer, the paint soaks into the wood without sealing it first. This allows dark colors of the wood to leach out or the paint to not cover the surface of the wood (it just soaks in and doesn't cover the wood).

Answer 4

Primer is just a cheap sealer. If you don't use it, you will use more of the paint, which is more expensive and will take more coats.
I have painted with and without primer. The final product looks the same.

Answer 5

The old paint color can bleed through or change the color of the new paint. Also, any stains or nicotine can come through. Put on a good coat of Kilz and you'll be okay.

Answer 6

the finished result is sometimes nicer, because the primer will even out all the different color tones or it will help seal the surface you are painting, but basically, you will need less of the paint color, because the first coat is sometimes absorbed by the surface unevenly.

Answer 7

It depends what you are painting. The paint may not stick, or you may have to put many coats on. Or the paint under may bleed through.

Answer 8

Well I've had the paint appear uneven, I've had to use many top coats to get adequate coverage, I've had bleed through of the orginal color, I've had performance issues like crackle, peeling and bubbling and I've had the wall absorb the paint and I've had stains, discolorations and yellow bleed through the top coats over time.

Answer 9

To little info. What do you want to paint. a Car? then primer is a must. Wood? Yep again sealer is a must. Wall's? Again yep.

Answer 10

The paint falls off :-) Maybe...it really depends on what you are painting.