The story so far...Some of the 3x2" box section beams were rusted through underneath. So i took the boat on it's early-model trailer to my shed. When unloading the hull, forgot to use the tilt function of the trailer so the already rust-weakened frame buckled under the hulls load (and became the tilt function!)
So now, aside from buying a brand new trailer at great cost, the other choice is to scrap the old frame entirely and rebuild/weld-up a new frame from scratch, re-using all the old fittings and running gear. Hopefully it's far stronger than before. It's also a good chance to add extra cross beams and rollers etc in a new design and prevent a "stuck on trailer" problem I've had.
My thoughts after seeing other trailers so far are to use open C section beams, so rusting can't ever hide internally. Increasing main beam vertical width to 4" or more (still 2" width to fit wheel assembly) . Buy pre-galvanized steel and zinc prime the joints. (Hot dip galvanizing would be the ultimate but moving the heavy frame could be a big problem). The main design change is to increase the draw bars length by a few feet (to get the trailer deeper underwater for launching/retrieval)
Work so far - sledge hammered the old frame straighter again, stripped all the fittings off, took allot of measurements and made drawings of it, left the old frame intact for use as a template/workbase and took some photos along the way.
So before buying the wrong-sized steel (and stuffing it up) some detailed info of other investigators trailers steel beams would be greatly appreciated.
