Here is a link to a inside 90 degree bracket, but they make hundreds of styles of brackets.
http://store.eberliron.com/images/products/p1325.gif
I would not make a trailer out of the unistrut itself, but you could make some very nice racks and roof racks. The channel will hold a ridiculous amount of weight.
http://store.eberliron.com/images/products/p1325.gif
I would not make a trailer out of the unistrut itself, but you could make some very nice racks and roof racks. The channel will hold a ridiculous amount of weight.