3 Point Hydroplane building from plans

[soccerrj88]

Hello to all... I'm looking at building a 3 point hydroplane as a hobby. I have found the plans for 3 different types or just different plans. They're called the Hasty Hydro, Scat Cat, and the Saucy Shingle. Has anybody built one of these? What was the cost/time? I plan on powering it with a '96 8hp Johnson. This is just supposed to be a low budget first build thing b/c I've always been interested in building boats so I'm not lookin to spend to much money. I don't plan on fiberglassing the whole thing, just the edges is what the plans call for with some fiberglass tape and resin. Does anyone have some finished pics that aren't from 1960's B&W or have any insight on which would be better from the three or even plans I haven't found. The plans call for Fir, but that's kinda hard to come by here and really expensive if I can order it, so what would be another good strength to weight ratio wood to use for this? Thanks for the info.

[matt_unique]

I owned something called a Skip Jack in the 80's. It was built in the 70's from plans featured in Popular Mechanics. I've also built two 8' dinghy's using the stitch and glue method, I suspect the same method your plans are calling for.

The time, effort, and cost to build this boat will be a lot more than you probably realize. For example, it's much cheaper to buy a plastic dinghy at West Marine than it is to build your own from plywood. With that being said, it's a great experience and you can really customize it to your own liking. You can use regular plywood, but it has a lot of voids and has to be covered with epoxy resin (all of it - not just the joints). This will be a lot cheaper than marine plywood, and is probably a good idea for your first build.

The dinghy's I built required about a month spending some good hours every weekend. As I recall, the cost was about $850 for me to build an 8' dinghy. I assume your hydroplane will be 8' as well (length of standard plywood sheets).

There is a steep learning curve but in the end it will be fun to ride the vessel you built. Good luck.

[soccerrj88]

Thanks. It doesn't call for the stitch and glue method. I saw a plan to use that method with a glass bottom dinghy. One plan calls for just a sheet of plywood and then build up from there - hasty hydro. The other two require a ribbed frame to be build and then cover with cut plywood. The first one will undoubtebly be an easier build and most likely cheaper b/c the list of materials for it are a quarter to half the length of the other two. Unfortunetly, it's the one with the least amount of detailed plans... I'm sure I can figure it out though. I'm pretty good with wood and it will most likely be a father son project and he was a carpenter for 26 years so we should be able to figure it out. I was just curious if anyone had any problems with these builds that they faced.
How much fiberglass would be required to cover the bottom of an 8.5' boat? The whole thing? What would the resin to cloth or mat ratio be? Should I use mat or cloth? I've done very minimal fiberglass work, so I don't know much about it. I say that West System had a material that when wetted down, it turned clear. Would that be best especially in order to show off the wood? Where can I get the fiberglass material, and what weight do I use? I hope i didn't overwhelm you guys with questions! lol
Heres the plans for anybody that wants them free otherwise Glen-L wants $50 for them.
http://www.muskokaseaflea.ca/staticw...d=60&Itemid=41 Hasty Hydro

http://www.svensons.com/boat/?p=HydroPlanes/ScatCat Scat Cat

http://www.popularmechanics.com/outd...g/1277141.html Saucy Shingle

I live in Central FL. Does anybody know a good lumber yard around here. (Lakeland specificly) The plans call for hard to get wood that Lowes and Home Depot don't carry and a few yards I talked to. Again thanks for the info!!!

[matt_unique]

Well there is no "stitch" at the bow but you will need a way to hold the stringers in place. You can use nails I suppose. The strength will come from fileting and fiberglassing (with cloth/resin) in each of the seams. You don't want to try to apply fiberglass cloth to 90 degree angles. You need to apply epoxy paste (epoxy resin thickened with something like coilloidal silica) to fill the corners of a seam such that the fiberglass cloth can be laid over a seam with a gradual turn.

You don't need to lay fiberglass cloth over the entire bottom, just the seams. You will need to paint on fiberglass resin over the entire boat, inside and out though. This is what will make regular plywood waterproof.

I don't remember how much resin you would need....it's the most expensive part of the build. You can buy it as you go of course.

[Cooper]

If you haven't done any reading at bateau.com, you should. The site has a lot of information about building plywood/fiberglass boats. Most of it is in the form of tutorials and notes about the plans they sell, but the same principles will apply to what you want to build.