A perfect finish on plywood panels can really transform the look of your boat.     In an earlier article, we stripped out the sagging vinyl lining of a Westerly Seahawk, which had suffered from the hot summers of the Mediterranean. The heat had loosened the glue, and gravity had done the rest. After a few days of hard work removing the old material, and cutting and fixing new linings, the boat had been transformed throughout. This month, we turn our attention to the panels that are found under the deckhead and coachroof. These are usually made from plywood, with a covering of vinyl, and are held in place with either screws or Velcro.

On a new build, cardboard templates can be made up to create close-fitting panels, and on older boats, the originals can be taken down and used as patterns. As with all vinyl linings, leaks from deck fittings, the onset of mildew, and excesses of heat can cause deterioration, but replacement is straightforward and enjoyable. Because the panels are designed to be detached, they can be taken home and worked on during the winter.

To see how the professionals work, we paid a visit to Hawke House Marine near Gosport. Proprietor Alan Dring made a dummy panel to show the various corners and apertures you may have to deal with.

Preparation
You need a wide, flat surface to work on, preferably at waist level to preserve your back. Failing that, a garage floor will do, or your patio. Sweep any dust or grit away, and place a sheet of cardboard over the floor to protect the decorative face of the vinyl.

Vinyl can be purchased either with or without foam backing. The preferred choice is usually foam, as it retains warmth and covers up any small imperfections.

Using the old panel (or a cardboard template) as a pattern, trim a piece of plywood to the right shape. Examination of the old panel will show if you have any leaks under the deckhead, which can be fixed while the panel is down.

Alan prefers to use 6mm ply for his panels, as it is able to absorb stapling better, although if you have a curved cabin, you may opt for 4mm instead. If using 4mm, be aware that stapling may be a problem, as the staples will go right through, so the entire job will have to be glued. The plywood should be WBP (water boil proof) exterior grade. You don’t have to use the more expensive marine grade ply.

When using foam-backed vinyl, Alan applies waterproof PVA glue, as opposed to contact adhesive. The PVA soaks right into the foam for a better bond, and has less toxic fumes. It is also better at resisting high temperatures, which can cause contact adhesives to fail.
For our demonstration, Alan used a piece of pre-cut 6mm ply, with a series of corners, and the added challenge of a circular light fitting in the centre.