Applying Bottom Paint to Your Triumph Hull


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Materials Required:
Oil based bottom paint (Pettit- Trinidad, Interlux- Bottom kote, or similar
3M- 94 Primer
Lacquer Thinner
Clean Rags
Masking tape
Brush and Rollers

Tools Required:

Random orbit sander with 80 grit paper
Propane torch


  1. Painting the bottom is easiest with the boat upside down or suspended in the air. Identification of the water line is best done by placing the fully rigged and loaded boat in the water and noting the location of the water line.
  2. Mark the location of the water line with masking tape and lightly sand the boat up to the tape line using the random orbit sander. Try only to scuff the surface.
  3. Wipe the bottom of the boat clean with lacquer thinner.
  4. Caution! Be sure that the lacquer thinner and any rags with lacquer thinner are put away and away from the boat.
  5. In order to improve adhesion to polyethylene it helps to "flame treat" the surface. This is a very simple process where the blue "oxidizing" portion of the flame is quickly passed over the hull. The motion of the torch should be constant and not linger in one spot. A one square foot area can be treated in about 5 seconds. The objective is not to melt the plastic, but to "flash off" the surface. It is much like spray painting- keep moving.
  6. As soon as you are done flame treating the surface, wet a rag with the 3M- 94 Primer and wipe it over the hull. The primer goes on in a very light coat and dries in seconds. Do not put too much on or go over an area too many times.
  7. The bottom is now ready for bottom paint. No additional preparation is necessary and paint can be applied immediately. Follow the application instructions on the can of paint.
  8. If you have specific questions regarding this process please post them in the Tech Talk forum.
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