Friday, May 21, 2010

Roof/right rear (4/29/09)

Clearly, the aft passanger side of the roof had been leaking. Some rot was evident then I remove the rubber roofing. The actual corner was in poor condition and had to be rebuilt before I would replace the roofing material.

I sat back and digested what I was seeing and played mentally with alternatives for the rebuild. I did consider ripping everything off and raising the roof in the center as is now done in newer models, so that any water will run off to the sides. Could not find a band saw thru my network of friends, so dropped that very labor intensive and unnecessary alternative. Most of the luan under the rubber roofing was ok. The forward 4x8'panel had been removed by someone else when this rig had an earlier roof replacement or repair, and did a poor job. The metal framework up forward was rusted, and the Blue Board Dow foam insulation was not bonded to the luan as it should have been. The 1" x 1.5" box steel tubing framework of the roof, had been bent downward slightly by some heavy bozo or 2 some time in the past. This was just forward of the A.C. and caused puddling of water on the roof.. It was slight but meaningful. I set up a very simple screw jack and wood system to press the metal framework back to original position (about .5")

Once the frame was about right, I used a high speed grinder and 24 grit disc to clean up the metal, then used Ospho (phosphoric acid) to etch the metal back to a good state.

I had to cut and pry out the center panel of insulation to get to the metal frame, but with some HD Liquid Nails, was able to rebond the under panel to the metal roof beams.

This was allowed to set for a couple of days, only one is necessary for full bonding. Now with the roof straight, material bonded together and cleaned up, I can apply a fresh sheet of luan....bonded with HD Liquid Nails of course.

The same surgery has to be done to some extent in the rear passanger side corner, but mostly wood work and luan replacement.

I am opting to square off the rear roofline instead of the early 90's round shape. I think I can get a better sealed job when done and that is probably why new rigs are done this way.

Only some of the wood had to be removed, but everything was scraped and cleaned up. Metals were scraped and ground shiney again, then treated with Ospho, before applying new wood. All wood and all work will be done with Mechanical fasteners as well as a chemical bond (HD Liquid Nails or Epoxy resins and fillers)

Nothing too strong ever broke, they say and since I only want to do this kind of work once, I'm putting all my best thoughts and energy into this project for a one time fix.

Measure twice, cut once is easier said than done working on something like this.. I can't tell you how often I needed to measure 3 or 5 times to get it right. Doable, but patience is needed.

Got the back corner squared away this afternoon and will get into the replacement of luan on a small area in rear, the front. Thats tomorrows job!

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