Do I Use Primer?

[CKNavy]

I'm getting very close to painting the hull of my wood ship. Some people say to use a sanding sealer first, and I have seen others just use primer to prep the hull.

 

Does anyone have any tips or tricks they can share to prepare the hull for paint.

 

Thanks,

CK

[Jaager]

It has been year ago, but the sanding sealer that I used was thick and produced a significant layer.

For furniture - especially on open pore wood like Oak or Walnut or non-Birch plywood it is a useful

prep.  It could have out of scale effect on a model.

 

I favor the traditional:

1) super blonde shellac flakes 5% solution in denatured alcohol or 100% isopropyl alcohol *

2) pure Tung oil 1:1 with mineral spirits as a primer.

 

The first coat is ragged on and wiped off after a few minutes.  It soaks into the wood instead of leaving a surface layer.

 

* Normal super blonde shellac is 10% soln.

The off the shelf garnet shellac is ~20% - the waxes increase its solubility.

[genericDave]

I haven't used a sanding sealer, but I pretty much always use a lacquer based primer on everything I'm going paint, but I think it depends on the effect you're looking for.  I use acrylic paints (water based), and find that without a primer, the paint tends to raise the wood grain a bit.  So, things that are painted without primer look very 'wood-y' and show their grain.  When use primer (and sand after the primer dries), I get a much smoother finish (often showing no wood grain).  I like that really smooth look so I always use primer.

 

The primer I use is Tamiya Liquid Surface Primer (grey), and it goes on very thin.  So thin that it won't fill any holes, and any defects in the wood still show up.  Since it is lacquer based it is a bit of a pain to clean up (can't be cleaned with water), but the results I get are worth it.

 

I used it on the hull of my Phantom and Bluenose builds, but I think it really comes down to personal preference.

[jhearl]

One advantage to a primer over a clear sanding sealer is that it will show up any defects that need to be repaired before painting the final coats. I always find something that needs to be fixed. On hulls, I usually use something like Rustoleum or Krylon in a rattle can from the hardware store. Of course, it has to be sanded before applying finish coats.

 

Cheers -

John

[Worldway]

One thought is to wipe on a coat of polyurethane before painting.  Has anyone tried that?

[bluenose2]

Hello Les here. A question. Are you able to spray the hull with an air brush or rattle can? If so this is the way to go. Simply pick a flat lacquer rattle can of Varathane or you could use a solvent based clear coat. Be aware that solvent based paints take 12 hours to fully dry where lacquer is ready in about 2. So same day workability. Blow two light coats on and give a light sand between coats. Your now ready for any paint. What I have found out with brushed on primers is they lay down too thick and your forced to sand out the finish to make it smooth before paint. If you are going to paint a hull with colours it is best to use an airbrush so you can tint the primer to a close final coat colour.

[Canute]

Some of the hobby primers, such as Tamiya, go on pretty thin. They are formulated with finer pigments, to keep them lighter. And it comes in rattle cans, too. Here in the US we also have Scalecoat, which is solvent based. It comes in rattle cans, too. It's a finely pigmented lacquer base. You'd have to find a local shop catering to model railroaders for Scalecoat. Many shops don't stock it, since mostly the hard core prototype modelers use it. I like it because the final colors dry to a gloss. Very helpful for decaling.

[mischief]

Depending on the look I want, traditional rough or modern display.  If for display, I use several very thin coats of water based white paint as a primer and sand paper with elbow grease.