Fiberglassing over carvel planks

[Dao]

I have a 1955 40' carvel double planked Navy Liberty launch that has been converted into a cruiser. I was in Florida a few years ago where I got teredo worms. Since I have taken the boat to New England and have had the boat in the water in the summers and take it out for the winters. I am considering fiberglasing over the hull. I'm looking into the different types of glassing polyester, vinylester (hydrex 100), epoxy. I want to take the boat back to Florida. Any suggestions?

[Mike Vogdes]

Dao,

Give the search function a try at the upper right hand corner, you will find plenty of info there. This particular topic is a touchy subject here but you will still get alot of info in short order.

[Keith Wilson]

Ok, guys, be nice to him . . .

The general consensus is don't do it; it will wreck the boat. Wood, particularly in large pieces, is dimensionally unstable. A carvel-planked hull is designed to work with the dimensional changes. A relatively thin skin of fiberglass doesn't move, and is not strong enough to resist the motion of the wood.

Find a copy of Alan Vaitses' "Covering Wooden Boats with Fiberglass". He describes a method by which a very tired old wooden hull can eke out a few more years of service. It involves essentially building a new fiberglass hull around the wooden one, fastening them together mechanically. The fiberglass is thick and strong enough that one no longer cares what the wood does. It sort of works, I guess, but you lose the possibility of ever repairing the wooden hull structure. The advantage of traditional wood construction is that individual pieces can be replaced as needed.

One technique that has been used sucessfully is epoxy-laminating several layers of veneer over the outside of a wooden hull, followed by fiberglass in epoxy. If done carefully after allowing the wood to dry out thoroughly, it has a good track record as far as I can tell. It has to be done well, though - there was an example a few weeks back on the Forum of a lovely old schooner that had been absolutely destroyed by a really really bad job of this type.

If it were my boat, and the hull was otherwise in good shape, I'd either pay very careful attention to my anti-fouling paint, or consider coppering the bottom (with metallic copper sheeting). There have been several articles in WB over the years about this process. It isn't cheap, but if you consider the cost of renewing the bottom paint regularly, it might be worth it.

[ChuckG]

Hey, I had a 40' "Liberty Launch!" I converted it to a salmon troller/tender. That boat wasn't anything if it wasn't stout. It was also (comparatively) easy to work on. (Of course, mine was an open launch when I started) Without having a details, I'd sure suggest replacing planks as required before I glassed over it.

How bad is the damage? How much of the backbone is involved?

[Russell Sova]

I wasn't sure if you or your boat got toredo worms. I hope it's the boat for your sake. You might consult fiberglassing books or plank her again like has been suggested. I wonder if it's true what Gannon and Benjamin say "there's no such thing as a good used wooden boat".

[Ian McColgin]

Firstly, the worms have probably grown. They are plentiful up here. The only limit is that few boats are in the water all year and thus the bottoms are in generally better tended condition.

I don't know if toredos can freeze and die in the winter if the boat's out of the water but anectdotal evidence is that they probably do not, at least not to a great extent.

You need to to a good survey to figure the extent of the damage.

Even with plank replacement, you're likely looking at a Viatsis style job at the least. Or a wood sheathing. No matter. It's only time and money. And blood. And sweat. 'Till ruin your marriage and cause your kids to grow up to be landsmen. But hey . . .