Can someone explain this to me?
I’ve heard many AT hikers say you gotta seam seal a tent to keep rain out during rainy days on the AT. But occasionally I hear a hiker (or even a gear manufacturer) advise NOT to seam seal a tent.
Which is correct and why?
JAWS
Depends on the brand. If it has factory taped seams, prob not. I seal the life out of every tent I get. Unless you like loosing your Pocketmail to a pin hole like Ken and Marcia did on the ADT last year. Water will wick thru the stitches and in some cases it’ll rain. It’s not 100% goof proof but for a little time spent.
Best homemade mix is GE Silicone II, 50/50 with mineral spirits and brush it on the outside stitches all over. Two coats, one on them, let dry and then one wider over the first. 1/2" is enough.
Bushwhack
For the most part, it’s pointless to apply seam sealer (homemade mix or store bought… both good) to seams that have been ‘factory taped’. So, yeah, don’t seal those that
are taped… applying a coat of seam sealer to the outside of factory taped seams wouldn’t really serve any purpose - IMHO - as the tape should have capped (but not PLUGGED!) the needle holes from the inside!
But not ALL seams get that tape! If the manufacturer (mfg) says ALL of the seams are taped, then good for them… but don’t take their word for it! My experience has been that most mfgs apply the tape ONLY to seams that are fairly flat and easy for THEM to get to.
Taped or not, here’s the important part…
Set your tent up in the yard just before a good rain sets in, and leave it there for 2-3 days while the wind and rain do their thing. Check on the tent every once in a while to see if any puddles are forming, and - if so - where they’re coming from. Don’t forget the vestibule area, since you REALLY don’t want to find puddles in your boots or on the gear you store there! If you’re not going to have a good rain for a while, you can try the ‘garden hose test’, but - IMHO - it’s a poor substitute for real rain and real (driving!) wind!
The corners of some ‘bathtub-style’ floor/wall seams don’t get taped, and usually NO seams or ‘sew-ons’ (loops or tabs for holding doors, windows and vestibule flaps aside) are taped in the vestibule area ‘outside the tent body’. For example, my North Face Tadpole 23 needed sealer in these areas. My Eureka Zeus 2 EXO had NO sealant along the floor/wall perimeter seam, which was not a good thing, given that it’s not a ‘bathtub-style’ floor… a three day rain test showed a good bit of weeping through the ‘double lapped seams’ via the needle holes! Also, the Zeus had no sealant on the seam that joins the vestibule (NOT the door panel, which IS taped!) to the tent body… the seam is ‘outside the tent body’, but rain water weeps through the stitching and drips onto/through the mesh door, creating a couple of very ‘nice’ puddles about 1 1/2 feet INSIDE the tent!! And that little toggle loop for holding the vestibule flap open… yep, it wicks the water right on into the vestibule. The Zeus required a LOT of seam sealing, even though ‘the seams were factory taped’… NOT!
Once you’ve located the leaky spots, if any, you really should find a porch railing or the like to use as a ‘stretching’ base. Turn the tent inside-out and pull the seam to be sealed nice and taut along and across the railing, and then work the sealant into the seams and especially the needle holes, using a small, stiff-bristled brush. A thin coat on the INSIDE seams, let dry for about 30 minutes, then another thin coat… like BW said. Set aside some time to do this, as it does take a while… but a whole night spent wet and miserable inside of a leaking tent will seem like a lot longer while, for sure!
So I guess the short answer is… test the tent in the rain, and if it leaks ANYWHERE, then it needs to be sealed!!
TBott
Those are some pretty detailed answers - I really appreciate it. I had always thought it was wise to seam seal until I read some manufacturers recommended against it. I hadn’t thought about the taped seams.
Also will try your suggestion(s) for which seam sealer to use.
JAWS
Look at it my way. Nothing ruins a good night sleep then having to wake up in the middle of a down pour to SEE if your tent is dry. I’ll do a little extra at home, hose it down or even do some over nights in the yard with rain, to see if its bomb proof. Thunder storms are more fun when you just have to listen from your taosty bag, not take part in a Noah’s Ark redux. :cheers
Bushwhack