GRP vs Wood hulls, Alum. masts vs wood

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Re: GRP vs Wood hulls, Alum. masts vs wood

Post by capt.fred »

Please forgive this 83 year old for almost repeating a post I did last year. Back in 1974, I had two or three months of sailing experience, mostly on an all teak 34' Cheoy Lee Lion. I found many soft spots even after the survey. GRP, after it is laid, you just forget about it.
In 1974 I was in the maintenance dept. as a planner at the Univ. Calif. Santa Barbara. I made 10K a year! I lived in a DIY boat yard with my honey and we built by our selves a 50' 23 ton cutter yawl The "Daedalus". 40 years after launching in 1977, here's an aerial video of her, solid as a rock with daily sailing as a 23 passenger charter. I wonder how much wood I would have had to replace in all those years?
We both sailed our 50 footer from San Francisco to the Alabama Gulf Coast in 1983 and never looked back.
Since I sold her in 2002, I have built several small boats out of GRP and have owned several larger GRP sailboats. I now own the worlds most beautiful small sailboat (to me!) a GRP 1981 Blackwatch 19 gaff cat.
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Re: GRP vs Wood hulls, Alum. masts vs wood

Post by Charlie P. (NY) »

When I was at a marina on Myers Point on Cayuga Lake the next marina over had Pearson Triton hull #1. It sailed frequently. Later a boat restorer based in Ithaca bought it and refinished it to "like new" specs. It is gorgeous.

That is one of, if not the first, GRP production boats made (1958 or 1959). Apparently they do not have an expiration date.

I built a 15 footer and used 6mm luan plywood with fiberglass on the outside bottom and chines. A good marriage for a freshwater homebuilt.

I've only ever been demasted once - and that was a wood mast I laminated myself (unstayed) that fractured dramatically while under full sail in a good wind. I replaced it with a one-piece yellow poplar mast (the straightest grained single piece of wood I have ever seen) that I had tapered by a professional woodworker who had the right equipment. No further problems.

Personally, I prefer aluminum masts. Though wood spars look right. Aluminum is certainly less upkeep. Just inspect the fittings and rigging frequently.
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Re: GRP vs Wood hulls, Alum. masts vs wood

Post by PAR »

I've owned both the all teak Lion class and the GRP version (Robb offshore design) and loved them both. The wooden boat sailed better because of her higher ballast/displacement ratio, but it was a lot easier to refinish the GRP version (even with her teak decks).

GRP hulls do last a long time, but don't be convinced they're maintenance free or can last forever, as neither is true. As a GRP hull ages, it tends to get brittle and depolymerize. Both can kill the boat. Additionally, most don't know, but these thermoplastics have memory and can distort in time, if a load is applied over a long period. The classic example of this is a the old 'glass powerboat, sitting on a poorly fitted trailer. They develop a "hook" in the "run" which can alter performance considerably and it doesn't go away without major surgery (read lots of putty). On a sailboat, particularly ones that are berthed, the sheer can be dramatically altered from rig tensions. Actually it's more than the sheer, but this is the area most immediately see. Trailer borne boats have much less chance of this, but do suffer from trailer fitment distortions, frequently.

Don't get me wrong, I'm not advocating anything, owning both large and small craft in wood and GRP. It's just that all hull shell material choices have good and bad things to consider. My 1960 John Atkins 37' cedar over oak power cruiser, has all her original planking, a few frame repairs and modest upgrades. It could have easily been much worse, but she's parked in a covered berth for the last 20 years and prior to me, was also well loved and cared for, so she's in good shape, with a dusty bilge after her last recaulk (carvel build). On the other end of the spectrum, I relatively recently purchased a 65' GRP ultra-light racer/cruiser (for her era). She's needed major and quite extensive surgery to address problems and fix production shortfalls. This isn't so unusual, as she was early in the production run, so the fixes and upgrades all production boats get, hadn't been realized by the time she was built. All hull material choices need to be weighed against a number of factors and none is ideal or best, except to most closely fit your requirements and skill sets.
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