The most common finish is Polyurethane. It comes in a few forms; interior, exterior (spar), and "poly-shades" (pre colored polyurethane). In its usual form, Polyurethane is a very hard finish that creates a shell upon that which it covers. The downside to this is that over time, the shell can develop small cracks if exposed to sunlight. The worst combination of elements for this finish is sunlight and humidity. Keeping your model in a spot out of the light will keep it looking its best.

Spar Polyurethane is specific to exterior applications. It is UV resistant, but not UV proof. Although strong, if placed in direct sunlight this is a finish that will need to be recoated after a year or two. For a model, this type of Polyurethane will work just fine. Spar is classified as a "soft" finish, meaning that it moves.

All Polyurethane is wipe-on, and may be applied by brush, rag or spray. Spray on is good for a quick recoat, although it will take longer to build up a protective finish. The brush method gives better coverage and brush strokes will level out.

A Quick Drying Polyurethane is good for a quick recoat time, but will require at least three coats to get the same finish of a brushed coat of normal polyurethane.

For a very strong finish, try an Oil such as Tung Oil, which hardens when exposed to air. The key with this oil is that it soaks into wood fibers before it begins to harden, forming a protective finish that moves with the wood. For model ships, this is a great finish to use.

Wax is also an effective finish. It shows no fingerprints and can be buffed to the exact shine you want.

Say you've purchased a model boat and want to make some changes. You can apply paint over polyurethane without a problem. All you need to do is rough up the surface before doing so. This will allow the paint to adhere to the surface. This can be accomplished by sanding with 220 grit paper. Following these instructions should work, but are not a guarantee. It is always good to do a test patch first.

With all that you put into building an amazing model ship, making sure to finish it off in the very best way will reward you with a remarkable collector's piece you can admire forever! Educating yourself on effective finishes will help you to get the best results possible.