Building a fiberglass shell for a small houseboat

[mikemac]

Hi all, new to the forum and needing some feedback. I came across a small houseboat design I would like to duplicate on an existing hull.

http://cgi.ebay.com/ebaymotors/1984-...QQcmdZViewItem

I am wondering if it is possible to build a shell along the lines of this boat on a hull. I would just buy this boat if I had the bucks but am looking for a project I can finance as I go. What would be the best approach to duplicating this on a 21' hull? I figure building an enclosure of wood and covering with fiberglass would be too heavy. So maybe something built over a mold and then glassed to the hull? I figure if I take my time I can get something to look factory, not looking to do something ugly. Any advise would be appreciated. Thanks Mike

[marshmat]

I doubt you'll get something that is both strong and good-looking for less than the $5,000 you would pay for the boat on eBay.

You could of course make a mold, lay up fibreglass, core and more fibreglass, add some reinforcing, etc, cut holes for windows and doors, join the shell to the hull, etc, but I don't think it would prove cost effective compared to the $5k houseboat you're basing it on. A decent mold alone would cost more than that whole boat.

[bearwen]

Mikemac,
Well the easiest and cheapest way to do it is to buid a male mold out of plywood and 2x4's then cover the wood with a thin single layer of fiberglass then gelcoat wet sand the gel coat and wax it really good (severall times) and buff it out then apply a mold release agent then apply gelcoat then apply fiberglass (the kind of fiberglass you will have to figure out I would use Biax or a good size roving several layers) then a thin chop mat layer then gelcoat when all of this is done take out the wood structure and there you go you have your shell gelcoated inside and out(I do not beleive you need to core such a structure unless you intened on walking on it if it is just to cover you then coring it maybe to much in cost and labor) I am not a marine architech so please ask around and do some research on fiberglass materials. To build a shell of this size will cost you roughlly $5.50 prsqft or so (at least where I buy my materials) that is without a core material plus the cost of the male mold.

Good Luck

[marshmat]

A full-span shell on a boat that size cannot be self-supporting without either a LOT of top-hat stiffeners or a reasonably thick core, or both if you plan to walk on it.

[Deering]

You could build a similar cabin on an existing hull using plywood with judicious epoxy/glass fillets and stiffeners. But it would still wouldn't be pretty.