Coating the Skin

The material we have been using for the past two years to coat the skin of the boats is a two-part polyurethane that we purchase from the Skinboat Store, in Anacortes, Wa. This is mixed one part A to two parts B and stirred THOROUGHLY. It needs to be well mixed to set properly, and believe me, to be left with a sticky, uncured mess on your boat skin would be a disaster of the first magnitude. On kayaks, the best way to apply this is with a scraper/squeegee, but with the additional stringers and multiple lashings making small bumps on our skins, the best way is with a disposable foam brush. Three coats can be put on a few hours apart, though in our school setting we have done coats on successive days, and it has worked just fine.

In the photo below, an acid dye (also from the Skinboat Store) called Russet (they carry 8-9 colors) has been used to color the canvas at the same time we shrink it. If you use just the polyurethane with no dye, the color will be a pale, yellowish transparent film, almost like skin of some sort.  To shrink the skin with no dye, just put the boat out in the hot sun, and hose it down with cold water.  Then let it dry.  If using the dye, but the dye in a spray bottle, and with a rag in one hand and the sprayer in the other spray evenly and then wipe to prevent runs. Once the entire boat is done, let it dry in the sun.

A perfectly good alternative is water based polyurethane from the hardware store. It dries fast; you can put on a coat every few hours, and build up to 5 coats quickly. For an opaque, color coat, mix ¼- ⅓ artists’ acrylic gesso and some acrylic paint of your choosing with the polyurethane for the first couple coats. Brush it as evenly as possible to avoid brush marks. Finish with 3 more coats of poly.