Fiberglass skin on old plank wood boats

This is a good point Ilan, there are boats and there are boats. Some boats are bronze fastened and expected to last, while other use iron or galvanized, knowing full well that come time to refasten will be the time she's ready to be hauled to the land fill. It's an important distinction. Most working craft are considered "disposable". They'll work until their loans are paid down and a reasonable profit is made, then sold or broken up for her gear. This is the way of life for these boats, unless some unknowing soul comes along and tries to make her into something else. I have a friend that made a sardine carrier a yacht and he still bitches about the fish smell. I warned him, but he just had to have it and no amount of bleach or paint has really gotten the smell out of that boat. The bottom line is; it's important to know what you have.

 

Correct me if i am wrong, and sure some of you will!!!
But did not the Royal Navy used to sheath the wooden hulls of the 18th Century ships (300 years ago) with a material called copper to do just this self same thing.

 

Other thing Loftsman.. totally other

 

Copper sheathing was used to protect the wood from marine borers and prevent/slow barnacle and weed growth. No structural function at all.

 

From memory there was a good article on sheathing wooden boats in 'The National Fisherman' around 6 years back.

The crux was that to be a lasting job the GRP sheath needed to be applied to an intermediate coating with a high modulus of elasticity that adhered well to the wood and the polyester adhered to in turn. There were reportedly good results with Sikaflex.

If anyone is really interested in this I'd recommend hunting up that article and reading it.

The notes on extra weight may not be all that significant. I have seen both wooden and steel boats even ferrocemented over that still passed minimum stability requirements.

 

9 out of 10 wood boats are fixed incorrectly. They use wrong lumber, think that pouring epoxies solves all problems or use wrong fasteners. I delivered a Chris Craft that was repaired in PR, had hold boat together in the middle of open sea with rope and tarp. Had another Chris Craft love his boat so much that he used wood hull as plug and built a fiberglass for it, then install his interior and running gear inside. He spent over $200,000 about 10 years ago on it, far more than it was worth.

 

Perfectly exact. The sheating was laid over a coat of linen embedded in hot tar, with the purpose that the copper would not be in contact with the wood. In presence of salt water wood/copper combination is a ill one as the acidic wood will begin to eat the copper and the resulting electrolysis will soften the wood. It's a similar electrolysis to the well known one between acidic woods like oak and steel.

 

To illustrate that with a good construction and maintenance there is no need of embalming a wooden boat in polyester GRP.

Copyright of the pic Jean Christophe Rey and http://www.bateauxdepeche.net

"Sainte Salsa II" was very well made by the Stento shipyard at Sete (France) in 1976 with the typical shape of these Mediterranean fishing boats. Length 21 meters Engine Baudoin 430 HP speed 12 knots.
The picture was taken in 2008 after a great revision with improvements. The boat is 32 years old on the pic!!!
The boat has surely more than 10 years of fishing life in front of it.

 

Yes I'm hijacking the thread, but hitting the nail again about well built wooden boats:
Copyright pics and infos Franck Delmas
http://www.bateauxdepeche.net/pageyvesjulien.htm

"Yves Julien" made in 1964 (no mistake 1964) at Sete (France) by the shipyard Averse. Length 17.94 engine Baudoin 285HP speed 10 knots.

First pic the boat is 41 years old. The boat is so sound that it's improved in 2007. The engine is changed after 43 years working 2500-3000 hours year and a few overhauls.
Look at the second pic. A lot of yachts are not so beautiful.

The boat is always working in 2012. It's 48 years old...

 

Examples are easy to find on both sides of the discussion. I have a 9 ton, 1960 carvel and a 3 ton, 1961 lapstrake (among other smaller woodies) , both essentially original, the the garboards have been replaced on both boats and they've seen their share to repairs, but the carvel has a dusty bilge. The lap has a few minor leaks, but is a trailered boat so not a real concern. The carvel has been berthed since it's construction with the usual haul outs and maintenance. I re-caulked her 5 years ago and she's been bone dry since. Her only issue since then was a popped butt block (I hate butt blocks and will eventually replace every single one).