Nothing enhances the appeal of a boat like brightwork: warm natural wood protected by varnish. Caring for brightwork is a continual chore, however, and one that you might enjoy, or not. Use only spar varnish intended for marine applications, of course. It comes in all price ranges and the most expensive is not necessarily the best. Some states prohibit the sale of VOC varnish in containers larger than a quart. You can order a gallon of a good marine varnish, named after a type of large military sailing vessel, for about $50, delivered, online.
about $50, delivered, online. Prepare the surface by scraping, How to power or hand sanding, or using a apply varnish heat gun to remove old
How to
apply
varnishPrepare the surface by scraping, power or hand sanding, or using a apply heat gun to remove old varnish, leaving only sound and well-adhered varnish or bare wood. The kind of pull scraper called a shavehook works best if kept sharp. A heat gun is best for large areas. The big problem with sanding is the dust it leaves behind. Finish by hand with 180-220 grit sandpaper. Remove all dust but do not wipe with water or thinner (alcohol is OK). Then, pick a good day and time: will blow dust, no direct sun because it makes the wood surface too warm, not too late if there might be dew overnight.
If you use a brush, it must be of good quality and perfectly clean. Disposable foam brushes work quite well when you flow the varnish on rather than painting it on. Use a ladle cut from a paper or plastic cup to move a little varnish into another cup so that you do not contaminate the whole can. Thin at least the first coat with a little naphtha, perhaps just a few drops and no more than 5%. If you must stir, do it slowly and gently; never shake. When brushing, work from a dry area toward the wet edge. If you get bubbles, change to a different kind of brush. When brushing gets difficult, add a little more naphtha.
Avoid getting varnish on the rim of the can—by dipping it out rather than pouring—and do not let bubbles form.
Let the varnish dry until sanding produces a fine dust, then rub lightly with 220-320 grit paper and apply a second coat. Two coats is the minimum over old varnish and bare wood needs at least four coats. In the south, tropical sun will eat away one full coat a month.
Prepare the surface by scraping, power or hand sanding, or using a heat gun to
a month. Avoid getting varnish on the rim of its Tips for can—by dipping the varnish out using varnish rather than pouring
Tips
forAvoid getting varnish on the rim of its can—by dipping the varnish out using rather than pouring it out—and do not bend the rim of the lid when opening it. Seal the can tightly and store it upside down. Avoid using steel wool, which leaves behind metal flakes that will rust. Scotch-brite pads can work well between coats with a little practice. Keep a small screw-top jar of varnish handy, along with a scrap of 320-grit sandpaper and a foam brush, for touching up spots that flake or peel before they make full refinishing necessary.