Plywood???

[Bern]

Just found this forum a few days ago, and it looks like a lot of good experience and suggestions are going around. Planning on building a sternwheeler, will be about 7 ½ by 22 foot. I keep vacillating back and forth whether to use wood or aluminum for the hull. Since the hull will be basically flat on the bottom, with square lines on the sides and stern, with simple lines on the bow, wondering about using plywood and forming the front by bending. After getting pricing on having a hull made out of aluminum, I am wondering if I could do my own fabricating using pressure treated plywood. Where can I find information on material thickness, floatation, supports, ideas, data, and everything I need to know? Any good net addresses, book suggestions, plans, etc.? Any and all feedback along these thoughts will be greatly appreciated. Thank You, --- Bern

[NormMessinger]

Pressure treated plywood is crap. Some get by with the better grades of fir plywood but use marine if you can.

Are you designing your own boat or do you have a designer?

Before you seriously consider aluminum check into steel. Cheaper, easier to weld unless perhaps you are an experienced weldor and have the welder.

Come visit when you get it build. I've got just the river for it near by.

Best.

--Norm

[John Bell]

How much does your powerplant and running gear weigh? If it's not too heavy, why not go with plywood pontoons? Something like Glen-L's Super Huck design might be a good place to start.

I've lately been toying around on the drawing board with my own plywood pontoon houseboat design. But it's for outboard power only.

I may be holding myself up for ridicule here, but I actually like pontoon boats!

JB

[Mike Keers]

Phil Bolger has a "Fast Sternwheeler" in his book "Boats With an Open Mind" (International Marine). It measures 25-6 by 7-8. It's pretty much a 'concept boat', I don't think any have been built. But the hull is classic Bolger Box, sort of a modified garvey. It's trailerable and 'instant boat', meaning plywood and tack and tape, etc. Cute thing, in its fashion. He hopes for speeds in the 13-20 knot range.

He discusses potential handling problems, as well as possible powerplants--I'd say it's a must read if you're serious.

He also gives a disclaimer at the end of the discussion, saying anybody prepared to go on with the design should be prepared to use it as a stationary houseboat, or repower with outboard motors if the 'fast'paddlewheel doesn't work out, or perhaps a wheel of different design, yielding a slower boat.

[wolfietuk]

Norm is right about pressure treated ply. There is exaustive discussions about ply in the archives. For your hull buy the best marine grade you can find bs1088. It will last and remember it is what is between your family and a swim to shore.

Rick

[Joe ( Cold Spring on Hudson )]

I was at my local marine lumber yard last week buying some Ply for my Stevenson Designed Catboat. When I was told the price of the 1088 1/2 inch Okume Marine ply $80 per sheet. I asked if there was a less expensive sheet, he looked at my 4 year old daughter who had come along with dad and asked if she would be in the completed boat. When I said she would, he said there was no cheeper Plywood - I got the hint, and bought the 1088 Okume

[TomRobb]

Did he get his training selling life insurance :D

[Joe ( Cold Spring on Hudson )]

Whatever he was trained in it worked. When you get to thinking there is only 1/2 inch between you and the deep blue you take all the precautions you can with that 1/2 inch you got

[Bern]

Thanks for the feed back on normal pressure treated plywood. I know how poor it is, I have used quite a bit of it in building buildings. However, since pressure treated plywood is said to last for thirty years, why not take top grade marine plywood and have it pressure treated? That way there would be less problems down line 15 or 20 years, and longer.

Bern

[wolfietuk]

The theory for pressure treated ply is that you take cheap wood. force toxic chemicals into it and these keep it from rotting. Marine ply is made from better grades of lumber with natural resistance to rot and glue them together in thin sheets with no voids. The result is thinner, lighter and straighted sheets. with no voids there are no spaces for moisture to collect and form rot. That is the comdensed version. Also check that 30 year warrenty. It has all sorts of provisos in it. Also if it deaminates and fails and your boat sinks, they will give you a new sheet of ply. In the overall cost of the boat good materials dont cost that much more and can make your boat last indefinately, if properly cared for.

Rick