Finally got the aluminum box mounted. It sets on the bumper, held in place by 2 4" square U-bolts, with plywood pads to distribute the load. I had i built to specific dimensions so it would occupy the bumper space to the right of the shore power inlet, which you can't see in the photo. The width only allows it to extend as far as the spare tire. I had it built with a front drop-down door which let me get the height needed to carry my air compressor and not interfere with the trailer tail light. The bottom photo shows angle iron welded to the bumper(both ends of the box) and there are self-tappers driven through the bottom of the box into the angle iron to keep the box from "bouncing" when the trailer is moving. I had the angle supports professionally welded and also the bumper welds inspected at the same time. Almost all of the weight inthe box is going to be directly on the bumper as opposed to having the weight leveraging on the bumper as with a reciever type carrier. The shop that did the welding said I would be fine and to periodically inspect the bumper welds. If I start to find any cracks, I'll go back and have supports welded frm the trailer frame. Total weight including air compressor, hoses, power cords, and leveling blocks will be less than 100lbs, so I'm not too worried about it coming off.
The guy that built it will do any custom size and the price was less than anything in Northern Tool. He charged me $275 for the box and it was $60 for Fed Ex to set it on my porch. If you are interested, PM me and I'll give you his email address. If it's OK with the Mods, I'll edit this post to include it, since it's not a commercial advertisement and I'm not making money from referrals.
Edited by Permission From Festus to include contact information: The guy's name is Mark Proul. His telephone number is 203-228-2164. He stays pretty busy so you may get better response by email:
[email protected]
He will build it to the exact dimensions yiu give him.
After a lot of thought, I decided that more support for the bumper probably wouldn't be a bad idea. I removed the bike carrier receiver hitch that wasn't going to be used for anything. It was bolted to a piece of angle iron on each end that was poorly welded to the trailer frame and in spite of that Keystone said, I don't think it would have supported 200lbs for very long over a rough road.
I took the trailer to a hitch shop that does a lot of work for me. They used 1/4" rectangular tubing and fabricated a crossmember that spanned the length that was used by the bike carrier and wire welded to the frame on both ends. The shiney bar in the left of the bottom photo shows the cross member. Also shown in the bottom photo is a short piece of tubing that is welded between the cross member and the trailer bumber. There are actually two of these additional supports so the bumper is attached to the tralier frame in 4 places. Also, in every place where there is a metal to metal seam, the seams are wire welded the entire length of the seam, no spot welds. I don't think this bumper id going anywhere except right behind me, where ever I happen to go.