fiberglass over wood?

Yes it can be done, but it can result in two hulls moving in close formation. The materials are very different, and it can be a lot harder than sometimes thought to get an unbroken adhesion of these materials. It is particularly difficult with planked or carvel boats, as there are a lot more things there than wood - tar, caulking, oil putties, paints, monel, copper etc. - and lots of joints. If the hull was not originally covered with glass during construction then it may be short term gain for long term pain. Just applying fiberglass onto an old hull with basic prep will not work. There is an immense amount of work to be done before you get to the glassing stage.

And if the hull is not gone right through to repair any loose ribs, joints, rot etc. then it is still a weak old hull - with a good finish. If you build up enough fiberglass to take over the strength of the original hull you will end up with a very heavy and expensive boat.

The plastic will always be stronger than the wood, and I would never suggest the use of polyester resins, they are too brittle. Vinlyester is a more flexible material that is used similar to the earlier resins, it is still not as effective in some applications than a good slow set epoxy formulated for timber use such as West System for example. Polyester is not accepted here in Australia when working on boats subject to survey. (I think that's probably similar to a U.S. coastguard certificate of seaworthiness, but I don't pretend to know that definitively.)

There are other epoxies on the market and I don't suggest any one over another, this is just one brand I have used since '91. - I was convinced after cold molding a hull in a shed, after the hull was complete I proceeded as usual to scrape the floor to get all the drops of glue off - every drop pulled off a bit of cement! And that floor had had 12 years of building activity on it before that West System came in the shop. There is no comparison.

Vinyl cloth is able to conform to sharper angles than glass mat, often a combination of the two will be useful.

Ferro cement over old carvel hulls has been used in Europe for many years http://www.ferroboats.com/ - often lighter and stronger than before.

I have glassed over several boats, nearly all ply/frame construction, and without doubt getting at least three coats of resin into the surfaces before any layers of glass is critical. I also maintain that this should be a decision of last resort. Without the entire structure being coated inside and out and internally, water entry into the timber will still be an issue. The timber epoxy construction methods of Gougeon Bros. etc is based on total encapsulation and sealing of the timber - the traditional design and structure of timber boats is based on subtle and very refined methods of preventing water getting into the timber where not wanted, and allowing the water access to timber where desired.

I appreciate that f/glass is good for maintenance compared to all timber construction, but locking up problems under fiberglass can be very counterproductive if you want to keep the boat, dishonest if you want to sell it.

It is a privilege to have the custodianship of a finely wrought timber vessel, often the timber is totally irreplaceable - the maintenance is part of the deal I believe.

Good luck, I have a couple of links below.

1

Yes, you can skin a wooden boat with glass.

Enhance the appearance? - the jury is out on that one

Cut maintenance? - In theory, yes.

You still have a wooden boat. This means that you should keep a 'boat repair' fund in your financial planning. Wood rots and isn't easy or cheap to repair.

You are probably better off putting the money you would spend on a new skin towards an actual fiberglass boat.

Yes you can cover a wooden hull with fiberglass and it is done on a very large scale with older boats. Please make sure that you sand down all the wood so that you have a clean surface.

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Along with stone, mud and animal parts, wood was one of the first materials worked by early humans. Microwear analysis of the Mousterian stone tools used by the Neanderthals show that many were used to work wood. The development of civilization was closely tied to the development of increasingly greater degrees of skill in working these materials.

I am a wooden boat guy, they are my babies.

Please don't cover the wooden hull with fiberglass.

If you want a new bottom look up the West System. www.westsystem.com

You can put a new bottom on the boat using this system.

that's a fairly common practice.

not that it will add a lot of weight.

for the hull exterior, you'll want to use epoxy resin, which is way, way, way more expensive than polyester.

fiberglass is good.