How to Apply Topside Paint

How to Apply Topside Paint

When you have waxed all you could do and your boat is still looking dull it is time to apply a new topside paint. Topside Paint not only makes your surface look good, it also gives you a critical protection barrier. Your topside paint will protect your boat from the water, wind, and rain that will pelt your boat throughout the season. Topside paints come in both one and two part systems. These paints can be applied with a brush or a roller. The single part epoxies are easy to use and have great adhesion but they will not last as long as a two-part system. The two-part polyurethane gives your boat great protection and will last for years. The following steps are general suggestions for applying topside paint. You should always follow the manufacture's suggestions when applying any paint to your boat.

Cleaning

Your existing surface should be cleaned of any contaminants and sanded before applying a new topside paint. Once you have pulled your boat out of the water, you should wash your boat. Your surface needs to be free of dirt, loose paint, rust, oil, grease, wax, soap, and any other matter. Do not sand before the surface has been cleaned because sanding can drive wax or contaminants into the gel coat. If you have bare fiberglass, you should wash the surface with solvent wash or a surface prep. If your surface has been previously painted, do a quick rub down of the area with a thinner to remove any contamination. Once the surface is clean check for any damage. If there is damage it can be filled with epoxy filler.

Sanding

Before you begin sanding, you need to check for any flaking and peeling of the old paint. You should remove any flaking paint with a chisel or a knife before you begin sanding. Now your surface is ready to sand, you should take 80, 120, 150 grit sandpaper and rub it over the surface. The choice of sandpaper is dependent on your gel coat's condition. You should be cautious when choosing your sandpaper. Too coarse sandpaper may produce scratch marks, which will show through your finish coat. Sanding should make the surface as smooth as possible and remove any imperfections. When sanding, you should always wear a mask and eye protection. Immediately following the sanding process, you should wash the surface with clean water or a solvent wash. Once the surface is dry it is time to apply the primer.

Primer

If you plan on using a two-part or a one-part system you should apply a good primer. Primers will add durability and depth of color to your final finish. You can brush, roll, or spray most primers.

Second Sanding & Final Prep Steps

Once your primer has dried, it is time to sand for a second time. This time you need to use a much lighter grade of sand paper. A 220 - 320 grit sand paper will work this time around. Following your second sanding you should blow the sanding dust off of the surface and wash with fresh water. You should now use a fine line tape to make sure your lines will be straight.

Paint Application

When it is time to apply your paint you want your paint job to have an even thickness and flow. If you choose to use a thinner, follow the manufactures recommendations for the best result. It is at this point, when you will mix your paint if you are using a two-part paint. You usually will mix part A with part B in a two to one ration and thin if needed. You should only mix what you can apply in two hours time. You have two main choices when applying your paint. You can either brush the paint onto the surface or use a brush & roll technique to apply the paint to the boat.

Brushing: If you choose to brush the final paint on you should get the largest brush possible. A brush with bristles that are flexible is the best choice. Interlux recommends using the Criss-Cross method when applying the paint by brush. Paint is applied to the surface with a diagonal brushing action from left and right (Step 1). This is then spread further with horizontal strokes (Step 2) before finally laying off with light vertical strokes (Step 3). (Interlux Product Manual). The Criss-Corss Method will give you the best possible finish.

Rolling: You should choose a high-density closed foam roller and a high quality bristle brush. These two tools will minimize the formation of bubbles. The roller will be used to apply the paint and the brush will follow giving you a smooth surface.

Addition Coats: The more coats you apply the better finish you will have. If you choose to add additional coats you should sand your surface with 320-400 grit sand paper and wipe off the residue with brushing reducer or clean water.

Safety

- You should always try and protect your skin and eyes. Wearing gloves, goggles, facemasks, and long sleeves can keep your body safe.
- You should always paint your boat in a well-ventilated area.
- Many paints are flammable; you should keep these materials away from flames and sparks. You should never smoke when using painting products.
- If any of the thinners, paints, or any other material contacts your skin you should wash with water and soap.
- You should always follow manufactures precautionary warnings and notices on products.

All information was taken and modified from Pettit and Interlux product manuals.