Help!! Building new cabin top!!

[timmydad]

My 1966 24' raised cabin top islander bahama has sustained severe damage all around cabin entrance way & deck area close to sliding companionway top. I want to build a sturdy wood box about 18" high 4' long & 36" wide, & bolt it to the undamaged deck top. This will not only repair deck but also give me standing headroom. The question is what type of wood to use and how to treat it(i.e. coat it with epoxy then enamel paint, fiberglass then paint or what) I've not worked much with fiberglass before. The boat only cost me $1,000. I've done most needed repairs already but need help on this one. There is no water damage to the deck other than right up against companionway frame of cabin. All suggestions greatly appreciated. Most of my sailing is done in a river with occasional foray out into the atlantic for daysail on calm days.

[sailingdog]

I would build a balsa or foam cored fiberglass box to do this... using solid plywood or fiberglass is going to make it very heavy when a cored laminate can do the same thing, be stronger and lighter. Also, instead of bolting it...it might make more sense to glass it in place... since that would make it an intergral part of the cabin top and make it much stronger and far less likely to leak.

Be aware that such a modification can either be done well or make the boat look like complete crap... so it really does pay to take some time to think it out and possibly even mock up a prototype before fabbing the actual piece.

[Delirious]

Check out Daniel Spurr's "Upgrading the Cruising Sailboat". He has instructions on adding a seahood fabricated out of fiberglass that can be expanded in size for your need (I think).

You're basically building an inverted dinghy if you think about it. I'd make a female mold out of plywood with outside framing (larger by whatever thinkness you want overall). Fair up the inside well and round all the seams with a cheap filler. Then wax it heavy and build it up with layers of glass and matt until you get it to the strength you need. You can glass in foam "beams" - the strength is from the rigid fiberglass tube over the form so the center doesn't need to be strong.

If you make it removable it will be appreciated down the road if you ever need to re-engine or pull the old for rebuilding.

[timmydad]

I have no exp. working with fiberglass which is why I was leaning towards wood. It appears fiberglass is the recommended way to go. Are there any websites that show how to for a beginner? Thanks again for your responses.
Steve

[mazzy]

Go to some boatbuilding sites such as glen-l, duckworks, etc for lots of info. Also, westsystem.com has lots of projects described, using epoxy resin with fiberglass
hth
Mike

[merc2dogs]

There are a lot of sites on boat building and reconstruction, with some very good advice on them

glen-l.com has a forum and several how-to's,
Boat plans, boat building kits for amateur boat builders

Plus a few decent plans, think it's primarily stitch and glue plywood designs, but the fiberglass information is pretty good.
Building Methods: Fiberglass Core 01 shows a method I've used on many projects long before I'd heard of glen-l. Depending on the complexity of the shapes, it's very easy. For complex curves that would be too hard to form in wood, I've used the foam both as a former and as the core. If you go this route, it's often cheaper to buy 2x4 or 2x6 stock and rip it down to make the form than it is to buy enough 1x. The exception is where you need a 1x4 or 1x6 it's much better to buy the right boards (unless you are equipped to resaw on the bandsaw)

do a search for boat plans, and browse around many have forums, and how to sections.


Ken.

[BlueWaterMD]

Agree with sailingdog. Foam or balsa core is definitely the way to go. It is lighter and stronger. No need to make a mold. If using plywood, get a high grade marine plywood. This will be a bit cheaper than foam core, but much heavier. Glen-L and bateau.com both have a lot of good info on this.