Instructions for barrier coating/bottom painting prep on a Foss Foam rudder while protecting your rudder’s One Year Limited Warranty.
When your new rudder arrives
Your new rudder is coated with Polyvinyl Alcohol or PVA. You will notice that it has a green tint on the surface. PVA is a mold release and helps the gelcoat to harden. To remove the PVA simply scrub/brush the surface with soap and water.
Foss Foam rudders are manufactured from a two-piece, clam style mold. The surface of the mold is covered with gelcoat and laminated with several layers of fiberglass. After the fiberglass has cured, we insert the shaft (for spade rudders) then pour our two-part 20-pound density closed cell polyurethane foam in one half and close and clamp the mold. The pour process takes less than 30 seconds. The mold is left overnight to cure and demolded the next morning. The rudder has a seam that is removed and covered in fiberglass mat and cloth. After curing the seam is faired and the rudder body is sanded. The entire rudder is again sprayed with gelcoat. When the gelcoat is dry the PVA is applied. Again, this helps the outer surface to cure.
When it’s time to barrier coat/bottom paint
Before you barrier coat/bottom paint we recommend that you sand the surface. Sand the body using a DA sander with 100-120 grit sandpaper. Sand the edges by hand as the seam is covered with fiberglass as part of the finishing process. Sanding the seam with a sander may result in the fiberglass being removed which will allow the seam to open up. We do not recommend using any dewaxing liquid or sanding aid. The use of liquid sanding aids or dewaxing liquids may lead to prerelease/blistering of the gelcoat surface.
Sanding/etching the rudder entails just breaking the shiny surface of the gelcoats outer surface. With proper lighting the process of prepping the surface should only turn the surface area dull or a flat overall finish. After sanding is complete wipe the surface with a lightly damp acetone or alcohol rag to remove and dust or oils.
Foss Foam Products of Florida, inc. incorporates over 40 years of rudder building experience into each rudder that leaves our factory. By following a few simple guidelines, we feel that you will be well on your way to a fun filed summer on the water.
Thank you for purchasing a Foss Foam rudder! If you have any questions, please don’t hesitate to contact us.