Like Stitch and Glue but with metal panels, more or less. Maybe instead of thick wires for temp joining use small squares of metal with holes and self tapping screws.
Welding might have prob bridging gaps in thin metal so maybe weld a few clips on inside of hull to lock everything in place, then bridge the panels with narrow but overlapping shallow "v" strips welded to panels on both sides to create chine protrusions.
A bit more information might help
Is it aluminum that you are going to use? What size of boat? What thickness of material?
Any time you have overlapping of steel or aluminum, you will more than likely have corrosion issues at the overlap sections. For steel, you will not be able to prep and paint all surfaces. For aluminum, more than likely corrosion will occur in the overlap section
Up to about 25 feet, an aluminum build, you can build a male jig from steel and layout the sheets that you need. (larger boats are hard to turn over) It is very easy to get the joints almost light tight and then tack the sheets together on your own. There will be certain times along the build that you can hire a professional welder to make up some joints. Then continue to fit the remaining stringers, decks bulkheads etc
If I had to build an aluminum boat from scratch at a length of over 25 feet, I would tend to buy a plasma, waterjet, or routed pre cut kit.
You might find that this is not so much more expensive than just a set of plans. The larger companies that supply precut kits will be purchasing literally tons of aluminum which reduces their costs SIGNIFICANTLY to the point that if they do not mark the material up a lot, the net cost on the material alone may save you money. As compared to going to a retail supplier of aluminum extrusions and sheets.
Additionally, the equipment would more than likely have a NESTING function which will optimize the material usage to reduce waste, another savings to you.
More savings will be had in that depending on boat size, a comprehensive time and material jig may not be required.
If you buy a plan that has patterns/drawings for bulkheads frames etc, you can make these up, tack together the jig, overlay the sheet, do your own tacking and final fitting, and hire a welder to finish
On most welded boats, the fitting up of the sheets takes much more time than the actual welding.
As far as thickness goes in aluminum, 1/8th is easy to Mig weld and I would recommend against Tig on full butt joints as the heat can cause distortion. Certainly there will be some who say that they can Mig down to .100, mmm?
Fillet welds, not too much of a problem, long butt welds without backing, at .100 are much more difficult.
So more info please
