Reanna and I have just about finished re-sealing our 1962 Kenskill travel trailer. Everything that was screwed into the corrugated aluminum that covers the outside of the trailer had to be resealed: access hatches, tail lights, door, windows. It turns out that this is hard work and takes a long time. We did not anticipate this, mostly because the instructions for the process are very simple: 1) unscrew the window or vent or whatever, 2) remove the old putty tape, 3) apply new putty tape, and 4) screw the part back in. No problem!
Reanna vs. Butyl Putty
These instructions leave several questions unanswered, foremost of which is how much of the old putty tape needs to come off for the new putty tape to seal well? Old butyl putty is sometimes impossible to completely remove with a putty knife, short of scraping all of the paint off the aluminum. No one mentions solvents in removing this stuff, but that is the only way I can imagine getting it all. Even the non-butyl putty, which gets crumbly and easy to scrape off in its old age, hides in the tiny crevices created by staples and folds in the aluminum and takes almost forever to remove completely.
Another question is how important is it to leave the paint on the aluminum intact. I found that I could speed up the process of chipping and scraping the five or six layers of rubbery and/or rock hard sealants on the roof vents using my putty knife at a sharp angle and hitting it with a hammer. Uncovering a vent could take two hours to uncover, pre-hammer technique, and now takes only just over an hour. Unfortunately, it is an unsubtle technique which inevitably gauges the paint and the aluminum underneath. Is this a problem? Even if we are going to cover everything in sealant?
Also, is there any advantage to using non-butyl putty tape? Our extremely reticent local RV repair guy would say only that he used butyl for roofs and non-butyl for walls and that butyl was stickier. People who talk about it online mostly seemed to use butyl. We found the butyl to be much easier to work with and stopped buying the non-butyl after a couple of rolls. Half of the wall-mounted stuff like windows are sealed with butyl now. Will that be a problem?
I’d like to share the several techniques I invented during this job, but I have no idea what the results will be during the next rain, much less in a couple of years. There are only three things that I know I wish I had known beforehand:
1) Don’t go to the putty knife too quickly when removing the remnants of non-butyl putty. You can get a lot of it off by rubbing hard with a wet rag for a while. It is not easy to do for hours, but quicker than going after each speck of putty with the corner of a blade.
2) You will probably have to throw away almost all of the screws you pull out, so you will spend a lot of money on new ones. And while you are correct in your initial assessment that the trailer is put together almost entirely of #8×3/4″ and #10×1″ screws, you will need a large assortment of other sizes because of water damage. I now have 3/4″ screws in #8, #10, #12, and #14, 1″ screws in #10, #12, and #14, and 1 1/2″ screws in #10 and #12. And several of those kinds of screws meant another trip to the hardware store to get them.
3) Sealing up the trailer will take a lot longer than a week if you have anything else you like to do with your life. More like three weeks. (Actually, I’m not sure I would have been better off knowing that one…)
And finally, here is the only video we found, after considerable searching, of someone actually applying putty tape. (Thanks, Canned Ham Trailers!)
Nathen's Miraculous Escape 