VARNISH GUIDE
SINGLE-PACK VARNISHES
Still the most popular kind. Brands include
International and Hempel, Epifanes, Jotun, Awlgrip, Skippers and Le Tonkinois. Many of these are formulated from long-established recipes – Epifanes Clear Varnish, for instance, was first made in 1902, while Le Tonkinois’ recipe goes back 200 years – and still include natural ingredients such as tung oil, pressed from the seed of the Chinese tung tree.
They are relatively inexpensive and easy to apply, and their flexibility is sympathetic to the movement, and expansion and contraction, of solid timber on traditional boats. Their downsides, however, compared with more modern alternatives, is that regular maintenance coats need to be applied, particularly in areas of high UV light. They are also relatively soft although some manufacturers produce a polyurethane version that gives a little more durability. While most single-pack varnishes have a gloss finish, some are available with a satin or matt finish for cabin interiors, and many others can have matting agents added to them.
TWO-PACK VARNISHES
Two-pack varnishes have been around for a good 30 years and they are currently produced by all the single-pack manufacturers mentioned above apart from Le Tonkinois. They are particularly good for filling grain on bare wood and for quickly building up film thickness, as in most cases multiple coats can be applied in one day. In fact, two of Skippers’ products – Poliglass and Acriglass UV – can have as many as six coats applied in a day. The chemical bond negates the need to sand between coats – which is not only labour-saving but also contributes to the faster build-up by not rubbing any thickness away – although many professionals might give a light rub to avoid an accumulation of imperfections. The finish tends to be harder – particularly with polyurethane two-packs which is what most of them are – and has greater longevity and so a reduced need for subsequent maintenance coats.
There downside is that they are more expensive and harder to apply than single-pack varnish, and as most of their hardeners contain isocyanates, there are considerably greater health and safety considerations. They are also less flexible, although this is less of a problem on cold-moulded or splined topsides, or on plywood. Acrylic two-packs are a little more flexible and a little easier than two-pack polyurethanes and they can also be polished which can be useful to remove dust from a less-than-perfect initial coating system or to breathe new life into a finish dulled by age.
SPECIALIST PRODUCTS
In recent years some varnishes have been specially formulated for oily tropical hardwoods such as teak and iroko. These include Jotun’s Benar Marine and also Epifanes Wood Finish Gloss. Coelan, a single-pack product that comes with its own primer (pigmented red or yellow), has been on the market for about 30 years. It is extremely flexible and has established a reputation for great durability, but it has a very short shelf life and there are varying opinions about the difficulties of application.
Deks Olje is another coating with a separate base coat and top coat. Deks Olje D1 is a penetrating oil. This can be used as a stand-alone matt product, but overcoating it with Deks Olje D2 varnish gives a gloss finish.
Hempel’s Wood Impreg is another saturating primer – introduced on to the market within the last two years – which can be used as a base coat for any of the company’s single-pack varnishes. Awlgrip’s Awlwood is a single-pack moisture-activated acrylic urethane varnish. The application process (which starts with its own coloured primers) is universally acknowledged to be very quick and easy, while its quality of finish, its hardness and longevity is seen by many as almost revolutionary among single-pack products.