Brettos,

Its soldered aluminum, The finders are made from a flat peice of aluminum formed
with a hardwood and aluminum mold. I use a propain torch. this place has rods you can get to weld aluminum.
The metal has to be very clean.
http://www.alumaloy.net/

The trailer was custom made for a Ready-to-Run Pro Boat Barrel Back, for a guy in Texas.
More pictures of the boat @
http://www.rcgroups.com/forums/showthread.php?t=405338

Thanks

Don M.