hull extrusions necasary?

[gomoto69]

I'm starting to build an aluminum hull to be fitted with jet drive. I'm trying to decide whether or not to obtain the hull and gunwale extrusions that some boat manufacturers use, where the bottom and side sheets of metal join together. Is this a better way to build as upposed to just welding the sheets together? I plan on 3/16 bottom and 1/8 sides. thanks

[Ad Hoc]

all depends upon the geometry, the access, the alloy grade and temper and the environment it is in...oh and your budget too!