Well, the summer flew by, we had some plans other than campering, so the Hawk got put on simmer for a while. But, we did sign up for the FWC owner rally down in San Clemente, so as Fall came around I reassembled the remaining items to take a trip. We're just back now, figured it is a good time to get caught up on my rebuilding adventures . . .
Going back to last winter, I had to decide what to do about my jack brackets before installing the new aluminum skin. They were a mess, with broken off bolts, also variety of different length and diameters. Sometimes there were two or even three broken bolts in the same hole. Here's a sample from the right rear corner.
The previous owner told me of problems backing his extra fat-tired Ram truck under the camper, he made up some extension plates added five inches of extension and lift. I feel both these might have led to an accident or two, stressing the brackets and breaking bolts.
The broken bolts were removed with vise grips or a dremel tool and screwdriver. Some were buried too deep, I couldn't get to them without destroying the corner tube, so they remained. At this point, nearly all the remainng bolts were loose enough I had to change something.
The first solution I thought of was replacing the corner tubes, which would probably involve gutting the camper first. While this would bring my camper back to good as new as far as the jack brackets, I wanted something thick enough to get more thread engagement. Reluctant, I thought of other options. Some kind of insert, aluminum or wood, coming in from the bottom seemed promising, but the remaining broken bolts were an issue. Eventually, I thought about rivnuts, or threaded inserts. These are made to be installed blindly, ie access from only one side. They are available in a few different materials - aluminum, stainless, zinc-plated steel. This seemed to be the ticket. I found a tool for a reasonable price, the
Astro-Pneumatic # 1442 and picked up a couple of pieces of aluminum tube to play with. On my test tube, I installed a couple rivnuts alongside a standard jack bracket bolt. I then started prying on both with a wonder bar, the standard bolt was quickly stripped and pulled out. I couldn't budge the bolt in a rivnut, although the aluminum tube was deformed. So, one downside, they might be too strong. Any further "accidents" might really harm the camper frame!
I chose 1/4-20 zinc-plated steel rivnuts, and 1/4" bolts to mount the jacks. Now, to put 48 rivnuts in by hand took a while. The existing holes were too small for the most part, for maximum insert strength the holes should be round and tight. I used a tapered reamer to form a nice round hole - drill bits will leave a hole slightly triangular, especially with a hand held drill/bit. The long reamer needed deep clearance, in most cases this was already in place as at least 1.5 inch length screws had been used. I had to drill through both sides of the tube in someplaces. Another problem was the less than precise location of the inserts with respect to the brackets. I really just had to go with the results, which meant modifying the brackets to some extent. In the end, I used a milling machine to slightly widen and lengthen the bolt slots in the brackets.