I'm preparing to update my Harbor Freight trailer to carry 4 boats and after scouring the archives for inspiration, I have some questions:
1) Why the metal bars?
Most folks have or carry poly boats which tend to deform on small hard surfaces. Wouldn't it make more sense to have a large soft surface that will conform to the shape of a boat's hull?
2) Why so vertical?
I'm planning to do 4 boats on a flat bed that requires a lift under 30 inches. Some of the designs are so tall that they are worse than cartopping an SUV. Seems like lower is better for lifting and for keeping the center of gravity of the trailer low.
3) Why load from the back?
Several designs force you to load the boats from the back of the trailer. I think side loading would be easier and less trouble.
4) Stackers vs. J-Cradles vs. Saddles?
I'm not crazy about saddles because they have to be adjusted for every boat and they want the boats upright. J-Cradles seem to work good at the edges, but would generally be in the way for side loading any other boats. Stackers can flip down and up allowing one to load 4 boats on a flat design.
I have a design in mind that uses thick wide foam on cross members and two sets of stackers to haul 4 boats that would all be about 28 inches off the ground. The foam is low density which should conform to the hull and hopefully be okay for long term storage of poly boats. The whole rig will be removable so the trailer can convert back to a utility trailer and the padded part can be used to hold the boats over the winter.
Let me know what you think. I'll try to get some drawings of the new design online soon.