Drive Hull Female Mold & Layup

People convert old outboards to electric drive, you can find them on youtube. It would eliminate all the 3rd hull thing and give you outboard steering and allow the unit to be tilted out of the water when sitting to prevent corrosion or barnacles when idle, or to raise somewhat for shallower water, especially if you mounted it on a jack plate.
Here's one that sounds a little expensive but there are others using golf cart motors etc.

here's more...
converting outboard to electric - YouTube https://www.youtube.com/results?search_query=converting+outboard+to+electric+

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Thanks Kapn I get it. At 24k lbs dryweight, my 50’ wooden trawler walks to port 3’ for every 1’ aft from a dead stop, maybe 3-5 secs at idle before there’s enough sternway for the rudder to do anything useful.

I’m comfortable landing with a lot more windage than this pontoon, but I was thinking it would be somewhat better in a very light, buoyant boat with a high torque motor. Thoughts?

 

A light buoyant boat will be affected much more by wind or prop walk. A trawler usually has a keel or deep skeg which helps with directional stability and reduces the turning radius.

 

So I've taken some helpful advice from the forum, I'm committed to a low cost, 'Frankenhull' fabrication. Here's an update on progress to date...

Donor hull, not ideal, but it was a great price (free).


Hull sides, after cutting out the center of the hull, and the transom, which was rotten.


Shaved the hull sides down to as close to true as possible.


Built a two-piece strong back with some temporary frames to hold the hull pieces in place.


Marked the hull side height with a jig from the song back and tried them down somewhat.


Milled a temporary keel section and 'pinched' the hull sides down to check fit.


Close-up of milled keel section centered on strong back, actual keel will be 3/4" coosa.


Trimmed transom and fitted a potential mold piece, but having second thoughts about a mold vs fitted coosa transom.


Updated design with a larger battery pack @ 800 lbs and motor mounted further forward.

Not pictured, I've also build a dozen stringers angled to the hull exterior, to clamp at the top of the hull sides, with an additional brace for each midway up.

In the interest of keeping this thread, I'll post my questions on a follow-up reply.

 

So next week I'm going to move the strong back, hull-sides, external stringers, etc, to an indoor heated space to screw and bolt everything together. While I've done a fair amount of glass repair, its been all tape and woven fabric, West epoxy, occasional fiber fillers, Awl-fair, and 545. This is my first attempt at a reinforced structure, or using polyester. I have some experienced help for the glass work, but I'd very much appreciate some guidance on the particulars from some of you. The general approach we're considering is to work all the laminate on the interior first - excepting the flange - before flipping the hull over to reinforce the exterior keel, bow, transom, and flange.

To start, I'm wondering about the best way to mount the hull sides onto the milled coosa keel. Seems like a good application for thickened, fiber reinforced epoxy, but given the layout it will be difficult to clamp the hull sections in place while the epoxy sets. Would it make sense to countersink small, 1/2" flathead screws every 6 inches or so, wiping away excess material with acetone? These screws would then be buried under successive layers of laminate. Would kevlar-reinforced Evercoat be an option, either for the initial bonding or as filet material prior to laminate? I have some on hand from another project. I had also thought to work with progressively wider tape for the entire keel interior, perhaps 3 or 4 layers out to 6", before working any chopped strand or 1708 material on hull bottom or sides. Does that sound right?

I've got alot of other questions about layup materials and process to get enough support in this hull, including beam and axial stiffeners, but I'd really like some feedback on the keel to start with. Thanks for any suggestions you may have.

Jack