Sealing a roof seam on a late eighties Winnebago

[Rickf1985]

I know repairing roofs has been talked about before and so has roof patching be I wanted to do this as a specific for these years of Winnies. The roof seam is strange and very inefficient So I have some pics of what I am doing. I have been chasing these leaks for three years now and nothing seals it. I got some good advice from Terry and I am going to go with a Polyurethane caulk since that appears to be what was used before. I thought it was silicone because the Proflex was not adhering to it, not even trying. And it sort of feels like silicone, kind of rubbery. Nothing I have tried will remove it. I used a oscillating tool with a scraper blade to get as much as I could, you have to be careful because it will dig into the fiberglass, real quick! I have been told that new Polyurethane will adhere to old and we are going to find out as soon as I get a window in the weather. I had to go out and get some caulk and by the time I got back my back was in spasms and I just was not going to be able to stand on the ladder and handle a caulking gun. Here are some pictures of what I was up against. I did ot get a lot of pictures because I was trying to get done today, still didn't happen.

[87Itasca]

I redid mine with 4" Eternabond tape, and so far, all my leaks have vanished, even in the hardest of rains.

[legomybago]

I'd say that's a great seam candidate for Eternabond. Did you try a wire wheel (soft bristle) attachment on a small grinder Rick? I would think if you were agile with the tool, which I know you would be, you could remove just the old gunk. That's what I would do/try in your situation. I haven't found an RV roof seam yet I couldn't clean up with this set up. Just have to be gentle.

[Rickf1985]

Unfortunately I do not have anything like that, I am set up more for metal work so everything I have is too brutal for this. I just cleaned it out with a nylon brush and air. I did get the first caulk bead in in between rain storms but it was not as pretty as I would have liked. It was effective though as I did get it all the way into the seam thanks to Terry's expert guidance. I was hoping he would post his caulking instructions here. I did not get any pictures as I was really up against the wall with the rain so I had to rust to get it done. It has been pouring since about an hour after I got done yesterday. I will climb under the tarp and hope to see that it is set up and sealed today. Will not be able to get pictures til the rain stops and that is not predicted to happen until next Monday! Six days of rain, You can come get it anytime Joan!

[87Itasca]

If you wanted to be doubly sure of a good bond, you could caulk the seam, then out a strip of eternabond over that. It seems to work great on my Windcruiser, which has an identical roof seam. I just used the tape though, but like I said, it's held up to everything this crazy VA weather has thrown at it so far.

[Rickf1985]

That is the plan but I want a good solid seal between the caulk and the tape which means another layer of caulk to bring it up to a point that the tape will contact it. Eternabond is great stuff but does not conform to irregularities well and I do not want any voids under there.