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-   -   full-timing, in an Airstream, in a rain forest ... (

NwilcoxM 04-07-2014 03:03 PM

full-timing, in an Airstream, in a rain forest ...
As you can tell by the title, we newbies to this are down and out. :confused: We bought and are in the process of redoing a 1974 31 sovereign in the mountains of North Carolina, while we live in it. It rains,on a good week, at least once. Last summer (the summer were NC got over 100 inches of rain) we tried to caulk all seams in a DAP non silicone product for aluminum but it failed because it needed 7-14 DAYS to cure! Then, we moved on to a aluminum sealant tape, and that worked for a while, but its so wet here, it also has failed, and we are at our wits end. Here's my question, before we spend even more money and time trying to seal this thing, what's the quickest and best sealant out there? We don't have the luxury of moving it to a place it can be covered. What about the new clear flex seal spray? Has anyone used it on their AS?

Belegedhel 04-07-2014 03:25 PM

With regard to using the spray stuff, the big question is how concerned are you with appearance? Do you intend to strip the clear coat some day and make it all shiny? If not, then the spray stuff is worth a try, but be forewarned that you will have a 2" wide spray mark, that may look clear from a good distance, but will be obvious when close up--especially if it collects dirt.

Now, do you need to spray every seam and rivet line? Probably not. I have gutted my '73, and most of the seams are gooped up with sealant from the inside. The places where it leaked were mostly because of bad door, window, and hatch seals, and around "penetrations," like the air conditioner, vents, refrigerator chimney, and especially, the plumbing vents. Most of these penetrations had a gasket installed when the trailer was manufactured. Those 40 year old gaskets have disintegrated, so either you reinstall them, or you scrape away the disintegrating gasket, and caulk around the penetration. I've used plenty of Vulkem (Trempro 635), and although it dries slow, it is usually solid within 24 hrs..

The plumbing vents are a particular problem. If you remove the cast metal pyramid shaped chimneys, inside is the protruding abs plumbing pipe. Surrounding that pipe, and acting as a "gasket" is a piece of rubber, that should be changed out every few years. Yours is probably 40 years old and is letting all kinds of water inside your trailer. You can buy precut replacements from places like Inland RV and, or you can go to a good hardware store and buy 1/8" thick rubber sheets and make your own.

The weatherstripping on the windows, doors and hatches (and roof top vents) should all be replaced. You can still order the original stuff, or find something that will do the job at the big box store.

good luck!

NwilcoxM 04-07-2014 03:34 PM

Thanks for the advice!
I forgot to add that we also replaced all the weather stripping around the door and windows, but have yet to address the gaskets. We will begin there and see it the tape really did fail and go from there.

I would like to strip the clear coat and give it a "matte" finish, but I was thinking of creating a sort of stencil for spraying the seams, so its a cleaner line of clear flex seal.

Belegedhel 04-07-2014 03:48 PM

I sprayed the flex-seal on some of my interior seams and rivet lines, just because I could, not because they were obviously leaking. It is a pretty messy product to use. You get one chance to go over something. If you have to take a second pass, you better wait until it is dry, or you just blow your first pass all over the place. It also doesn't go very far, and at $10/can, you can blow through a lot of cash in a short time.

NwilcoxM 04-08-2014 07:47 AM

where is the best place to buy Vulkem/Trempro 635? Is it applied like caulk?

Minno 04-08-2014 08:03 AM

Vintage Trailer Supply, Out of Doors Mart, Inland RV all sell on line. We've also seen it at Northern Tool and Equipment, and at Home Depot, and Menards. It uses a caulk tube to apply. Clean up and smooth out with Carb cleaner. Trempro is skimmed over in a few hours, and water tight within 24 hours, per our experience. Good luck!


Farmer Dan 04-08-2014 08:08 AM

I was able to get Trempro from my Fastenal store. I have seen other posts that also mentioned Fastenal for their tubes of Trempro. I ran masking tape along the seams to leave a 1/8" or so gap for the Vulkem. But before masking, I removed the old sealant with a heat gun and wooden scraper. Some other products besides wood can also be used as long as they don't scratch or gouge the aluminum. I used mineral spirits for the final cleanup before the tape and new Vulkem were applied. I wear throw-away vinyl gloves to smooth the caulking bead right after applying it. Remove the tape right after the bead smoothing. It is a messy operation for me, but not difficult.

NwilcoxM 04-08-2014 08:12 AM

if I did every want to strip the clear coat and polish, will I have to reapply it or will it stay on? (the vulkem/trempro)

Belegedhel 04-08-2014 09:52 AM

Typically, people will strip clear coat, achieve the level of polish they want, and then do their seam sealing. If you do it in the reverse order, you are running a polisher over a rubbery sealed seam, and it makes a mess (at the very least, the vulkem will collect black oxidation from the buffing wheel). So if you seal your seams today, someday you will be scraping away the sealer so that you can polish, and then resealing. For the sheet metal seams, you might also use Parbond--I use the Trempro for the bigger cracks.

NwilcoxM 04-08-2014 02:01 PM

how long does Parbond take to dry? And can I get it from the businesses listed above?

Belegedhel 04-13-2014 11:00 AM

Similar drying times to Trempro, and it should be available from the online businesses listed above.

J. Morgan 04-13-2014 11:28 AM

full-timing, in an Airstream, in a rain forest...
If a person masks both sides of a calk line with masking tape, and then uses a finger to press the bead into the seam while removing the excess, you will end up with an effective seal and an attractive result.

I used a white product that wasn't silicone, and it wasn't latex, but I can't recall what it was.. Sorry.

I got it at Lowe's, its consistency when dry is more firm than silicone, and more flexible than latex.

If I think about it tomorrow I will post up the name if I can find the tube.

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