How do I repair brightwork?
Dear Boat Doctor,
I really need to get after the varnish on my Tartan 37. It has been a few years and a lot of the varnish is starting to lift. I am not real sure where to start, and I need some guidance on how to go about this.
Brightwork is just one of those tasks, you take care of it and then it reappears soon after. The best plan is to maintain a good varnish job, but if you let it go, the easiest way is to really let it go; old varnish finds a way of removing itself.
You need to start by removing the old finish, and nature has given you a head start. I'd start with a heat gun and scraper. Heat up the remaining varnish and scrape it off with the scraper. It's a good idea to mask off the fiberglass around the brightwork with blue tape.
Once you have all the surface varnish off you'll need to sand the wood smooth. I'd start with 80 grit, go to 100 grit, 150 grit and finally up to 180 grit. At this point, the wood should be looking pretty good. If it is not, you'll want to use a good teak bleach and brightener. Any of the major brands should work just fine.
I would get the wood and surrounding areas very clean and aim for a nice bright, dry day. The first finishing step is to seal the wood. There are several good varnishes to choose from, I like to use one with a high solids content, like Interlux Schooner Gold (www.yachtpaint.com, 908-686-1300), and Epiphanes Gloss (www.epiphanes.com, 800-269-0961). Using your varnish of choice, thinned to 50%, apply a coat. This seal coat serves several purposes: It seals the wood and prepares for subsequent coats, it protects the wood from weathering after sanding, and it shows off any blemishes in the wood prep.
Assuming that your wood looked good after the seal coat, you are ready for a pre-coat of varnish thinned 25%. Follow this up with unthinned coats of varnish, as many as you have patience for-at least five on bare wood. I like to sand between every coat, but you can get by with sanding between every other. It is important to clean up between coats, and a clean rag dampened with whatever you thin with is a good technique.
As I mentioned, it is easier to maintain a finish than to replace it. You can keep your boat looking good by putting on a coat of varnish each year. Start by wiping down the wood with thinner to clean off any contaminants. Follow up with a light sanding with 320-grit sandpaper and another thinner wipe down to remove dust. Finally, brush on a coat of fresh varnish.