Fairing opinions

[Dan McCosh]

Just finished the two stories in WB about a: fairing using epoxy; and b: the merits of flat paint. I'm particularly curious about the technique of using a layer of epoxy fairing compound to fair a caravel-planked hull. Personally, I avoid large areas of epoxy fairing on the planking, on the assumption that this is an uneven, waterproof layer varying in thickness, with little reinforcement--bonded to wood that is swelling, shrinking and generally moving about. Seems like the worst case of a putting a layer of waterprood something-or-other on a traditional hull. Off and on, I've done lots of temporary repairs that end up with something similar, but they do tend to crack, peel, etc., over the long haul. Can't quite figure why this is an acceptable technique for a professional yard. Any opinions?

[Bayboat]

In an ideal world the fairing of a carvel-planked hull is done with a smoothing plane and a long, flexible sanding board. The perfectionist can finish with a scraper. A good job with these will leave little to fill in. I've always used trowel cement for the bigger dings and surfacing putty for the smaller ones. I don't know the chemistry or mechanics of it, but these seem to hold on well and are compatible with paint. I sense that epoxy is too hard, certainly to sand level and feather with the wood, and perhaps too hard to accommodate itself to the wood. As for yards that do a lot of "fairing" with epoxy, I would rather patronize one that has guys that are good with a smoothing plane.

[Ian McColgin]

I liked it as it agrees with my prejudices for preping a painted hull.

He starts by getting might fair the bad old fashioned way.

I agree that eopxy is a better bond than old time trowel cement and I happen to like epoxy as a base anyway.

The fairing epoxy is ever so easy to sand that from a production point of view, it's cost effective if not so over used that you spend more in epoxy than you would have in elbow grease.

I've always thought this was a technique that migrated from finishing steel hulls.

[imported_Conrad]

It's a cost effective way to get a great finish- until the plank seams start to crack. Best for hulls that stay wet and in a cooler, consistent climate. Think of glued seam hulls- all the same issues apply here.

[Walcheren]

Hello. I have built two small boats. 12 and 16 feet, carvel planked. Plane and sanding, random orbital, sanding blocks made to shape of the boat out of styrofoam, flexible boards, hand held for the minutiae and I got a "fair' hull. If one needs more then that there was something wrong with the setup I would think. Maybe in larger boat construction one gets into other situations. I would have no idea how I would fix any large "unfairnesses". The small ones, dents, yes, epoxy worked fine mixed with talcum powder, sawdust, balloons or whatever.

[imported_Spissgatter W-9]

Maybe the answer is "depends". If you've got new planking, then there is material to fair without compound. Now I've got an old boat whose frames have been broken, planks sanded and painted, relaminated, replanked in places and refastened, a couple times. Lots of flat spots. To suggest fairing the hull with a batten and plane would leave things pretty thin. So, I think Anna Marie is an appropriate candidate for the "fairing with thickened epoxy" process. It has also been "wedge seamed" so wetting out with unthickened epoxy before applying the fairing material should provide the recommended moisture barrier. Will let you know how it works out.

[Dan McCosh]

The mention of a "recommended moisture barrier" is the operative word here. Question is whether a moisture barrier on the exterior of planking is a good idea. In the past, I've avoided any surface that inhibits either soaking up or drying the planking, on the grounds that this leads to excessive cupping, encapsulates moisture, etc. On the other hand, I've seen planked hulls epoxy-coated with the seams glued, apparently with some success. Recently, a simple awlgrip job on a wooden hull ended up more or less a disaster. (awlgrip likewise is a good moisture barrier.) Ended up looking like shrinkwrap, with the seams bulging under a tightly-stretched layer of paint. Then again, another hull has been using coal-tar epoxy on the bottom, achieving a nearly flawless finish with modern bottom paints. I'm actually not so interested in fairing (the low-density West filler works great in this regard) as the effect of sealing the exterior of the planking with a watertight barrier coating. Hopefully some experience for five years or so in areas where boats are dry-stored.

[Allen Foote]

Time will tell with this method. 1 year in Florida sunshine is equal to how many Maine summers? It would be interesting to see the epoxy faired hulls in 5 years. As they say..."paint & putty, thier my buddy"