Fiberglassing Teak Handrails – An Experiment
The hand rails running the length of my cabin make up forty percent of the above-deck wood on my boat. After nearly thirty years, they were beginning to show their age with light rot and splintering as well as minor leaking at the mount points. Due to their size, low profile, and complex shape, cleaning, brightening, and oiling the wood would require several hours each year. To combat all this annual maintenance, I decided to tighten down the mounting bolts and fiberglass over the entire thing – sealing the seams directly to the hull, thereby eliminating any possibility of leaks. No cleaning, no brightening, no oiling, and no leaking!I wasn’t sure if fiberglassing teak would even work. A couple salty dogs I consulted claimed that teak wood was too oily to get good adhesion with the epoxy. I did some research on the internet and couldn’t find any concrete stories about successfully glassing over teak.
Adhesion is the key to success for any fiberglassing job. The handrails hadn’t been oiled in over a decade (as best as I could estimate). If they had been new, or recently oiled, I’d be inclined to agree with the salty dogs. However, the non-stop weathering made the wood look anything but oily.
In order to prepare the wood for fiberglassing, I used West Marine branded “Heavy Duty” teak cleaner and brightener. I did two successive cleaning and scrubbing sessions with the heavy duty cleaner in order to remove as much dirt and mold as possible. Next, I used the heavy duty brightener just as I would if I was preparing to oil the wood. The brightener contains a copious amount of oxalic acid which strips the old oil from the wood, as well as bleaching and brightening it.
Finally I followed up with a light sanding and laid down plenty of masking tape to catch any slop. I took extra care to sand the gelcoat around the seams where the handrails mated with the hull. I wanted the fiberglass to adhere well to both wood and gelcoat, thus sealing the seam and eliminating leaks.After all that prep-work, all that was left was to paint the railing with thickened epoxy resin. The final product was a little lumpy, but completely functional. Only time will tell, but I feel really good about the quality of adhesion. The wood appeared to soak up the epoxy deep into its pores. I completed this project just in time too, as we’ve had a very wet September. If you go the same route as me, be sure to do this project in summer when the wood is as dry as possible. Any moisture in the wood will be trapped inside. Too much could lead to rapid dry rot.
Next summer, I’ll sand down the fiberglass a bit and paint over it. I would love to leave the fiberglass as-is to show off the natural wood color, but I’m afraid the epoxy will crack with time due to ultraviolet light exposure. I’d rather cover it up and protect it. Leaving it exposed for a year shouldn’t cause too much light degradation and will give me a chance to fix any blemishes next summer.
Gelcoat would be the more ‘professional’ way to do it, but I’ve found that polyurethane cement sealer paint dries very hard and isn’t as lumpy when curing. It just needs dry, hot weather and a good week to cure. At $25 per gallon, it’s a lot cheaper!