There are several categories of topside paint, each of which has its own advantages and disadvantages. This is how they stack up.
Two-Part Polyurethane: The hardest, highest gloss, most durable paint.
Many can be brushed, rolled or sprayed, while others must be sprayed only.
Best results are usually obtained if it is sprayed. However, it is generally
more toxic
than one-part paints, especially when sprayed. Some two part polyurethane's
lift oil-based paints; check label or manufacturer's guides for more information
on compatibility.
One-Part Polyurethane: Similar to two-part polyurethane, but not quite as hard or durable. Ideal for do-it-yourself painting of fiberglass topsides, sheer strakes and boot tops. Although formulated for the amateur, many professional painters prefer them to all other enamels.
Alkyd Enamels: Traditional oil-based paints. Easiest to apply for the amateur using brush or spray. More compatible with under lying surfaces than polyurethane's. Most economical, flexible and least fussy in how it's applied.
Helpful Hints
The following is a list of hints we have accumulated from boatyards, manufacturers' literature and other sources.
1. Different weather conditions necessitate that you modify the topside paints you're using with thinners and reducers. Changing the paint's properties is one of the factors that separates the amateur painter from the professional. While especially true , with two-part paints, normal enamels will act differently when thinned with “fast” or slow thinners.
2. Try to apply paint in one direction without interruption.
3. When you spot a holiday (dry spot), resist the temptation to go back over it. Yes wait for the next coat to cover it.
4. Several thin coats are better than a few thick coats.
5. Paint hides underlying color, but not texture. The No use of sanding
surfaces, putties, sealers and sandpaper will have as much to do with the
final result as how many coats, or what type of
paint you use.
6. Paint when conditions are in your favor. Don't try it when it's windy, wet, late afternoon, foggy, snowing, etc. One additional lay day may save you from looking at a bad paint job for the next year.
7. Read the instructions on the can. It sounds simple, but you can learn tips that make the difference.
8. Good brushes are like good shoes or shirts; they may cost more, but they are a delight to own and last much longer than cheapies. Use cheap brushes with resins and solutions that will be tough to clean.
9. Use the fine line tapes to insure sharp, clean divisions between colors. Although more expensive, their thin profile and sharp edges will do a much better job than thicker tape.
10. Stir ,donut shake, enamels. Bottom paint needs shaking because of its propensity to settle, but shaking enamels causes bubbles that will be a pain. Most varnish does not need any agitation - read the label.
11. Clean the surface with a tack rag to remove the last vestiges of dust. If you use a solvent, allow it to evaporate completely before overcoating.
12. Do not leave bare wood exposed too long as it might absorb moisture.
13. Do not apply too much pressure, or use a high R.P.M. sander as it may glaze the surface. Frictional heat will soften the paint or varnish and load the paper.
14. Put a layer of plastic wrap over the surface of varnish and topside paint in partially filled cans. This will prevent a skin of paint from forming on the surface.
15. Clean brushes in used paint thinner that has been left undisturbed in a can. Thinner lets paint solids drop to the bottom of the can, and is reusable many times. Use clean thinner for the final rinse.
16. Finally, read the painting guides that the paint manufacturers give
away. The Interlux Boatman's Painting Guide, the Awlgrip Marine Applications
Guide, the Z-Spar Painting Systems Manual and other publications have a
ton of information that explains how to paint using the systems they describe.
We highly recommend reading them and following their procedures.
| TYPE
BOTTOM TOPSIDE
TOPSIDE
AND PAINT POLYURETHANE ENAMEL WATERLINE DECK VARNISH INTERIOR SIZE |
| 10 FT.
1 QT.
1 QT.
1.5 QTS.
DINGHY |
| 14FT.
1 QT.
1 QT.
1 QT.
1 QT. 1 QT.
OUTBOARD |
| 18 FT.
2 QTS.
1 QT.
2 QTS. 1 PT.
1 QT. 1 PT.
RUNAB0UT |
| 20 FT.
3 QTS.
2 QTS.
2 QTS. 1 PT.
1 GA. 2 QTS.
SAILBOAT |
| 24FT.
3 QTS.
2 QTS.
2 QTS. 1 PT.
1 QT. l.5 QTS.
RUNABOUT |
| 30 FT.
l.5 GA.
3 QTS.
1 GA.
1 PT.
2 QTS. 2 QTS.
2 QTS.
SAILBOAT |
| 32 FT.
l .5 GA. 3
QTS.
1 GA.
1 PT.
2 QTS. 2 QTS.
2 QTS.
CRUISER |
| 36 FT.
2 GA.
5 QTS.
2 GA.
1 PT.
1 GA. 1 GA.
3 QTS.
AUXILIARY |
| 40 FT.
2 GA.
5 QTS.
2.5 GA. 1 PT.
l.5 GA. 1 GA.
1 GA.
CRUISER |
Many of the solvents, paint components, paint removers and sanding residues
that are part of refinishing your boat are toxic. You should wear protective
clothing to prevent contact with them, and be especially careful to always
use a respirator, gloves, and eye protection. It wasn't very long ago that
people who used fiberglass and paint would wash their hands in acetone
and paint thinner we now know that contact with organic solvents should
be avoided whenever possible.