Tents, PU & Seam Tape

[Time Zone]

I have a couple tents on which the seam tape is starting to peel off. About 90% of what I find online about PU-waterproofed tents is that once it starts to fail, it's irreversible (and not really fixable), so how long you keep it after it starts to fail depends a bit I suppose on your tolerance for imperfect waterproofing (early on), and ultimately sticky nasty smells (later on). Every now and then I see something that implies you can fix such deterioration / delamination.

Is peeling seam tape basically the same kind of failure as peeling PU coating on the non-seam part of PU-coated fabrics? Or is it a different thing that can actually be fixed? I've been assuming it's the same stuff, and it's not really fixable (except maybe short-term - scrubbing off the loose bits and trying to apply sealant to the rest, meanwhile the rest of the original coating continues to age and fail).

If it's the case that I'm seeing the early signs of unavoidable waterproofing & PU-coating failure, then it is time to consider replacements. Currently I have a light, trekking-pole supported 1P tent (Sil/PU hybrid) for backpacking and a freestanding 2P double-wall dome for frontcountry camping. That combo has worked fairly well for me, so I may stick with it. (no pun intended! )

But I am tired of PU tents failing due to coating issues, long before they otherwise wear out. I always dry my tents 24 hrs before they get put away for the next trip, but I still only get a few years on average out of PU-coated tents. Unless it's a manufacturing problem, the only reason I can think of is that, after thorough drying out, I put the tents away as they came - in their stuff sacks. I don't store them loosely, as I do quilts and sleeping bags. Perhaps I should, but I'd rather not take up even more closet room with camping stuff loosely stored. I'm thinking if I could move to silnylon or silpoly, maybe this wouldn't be an issue. (Not interested in DCF)

This brings me to the question - I can't find many non-PU-coated tents that are freestanding 2P double-wall. Most silnylon or silpoly are single-wall or hybrid and not freestanding. I think I found three tents, two by Nemo and one by Tarptent, that fit the bill. Does anyone have other suggestions for a frontcountry tent replacement that fits the bill?

As for the 1P backpacking tent, the Durston X-Mid appeals most to me right now. Not a fan of "pre-ordering" anything after being burned in the past (non-backpacking related); may wait for his deal with Kaviso to expire and see if I can order it once he has everything back under his own roof and inventory. I guess they may still sell out though. Many other UL tents catch my eye. FWIW I am a bit tall at 6'1" and live in the southeast, so ventilation is often critical. Am considering giving another go at hammock camping, but I often am in designated sites (regardless of frontcountry or backcountry) so unlike long-distance and through hiking I don't often have the option to just keep hiking if suitable trees aren't in the immediate vicinity of the designated site.

Thanks for your thoughts - TZ

[Time Zone]

bump ...

and update: since I posted this I did come across a couple videos in which it was recommended to not even try to deal directly with the failing PU seam tape on the inside of a tent or fly, and instead, apply Seam Grip + WP on the outside of the tent, opposite side of the fabric where the failing tape is. Strikes me as a bit unsightly (only if you catch it in the light, since it dries glossy and clear) but people seem to do it, including Tipi Walter. Again, I guess it buys time until more extensive PU failure (like on the non-seam part of the fabric) and the vomit smell starts to assert itself.

[camper10469]

once the pu fails, all that seam sealer will fail as well as the pu you sealed breaks down under it. soon the tent will develope a foul odor n get very sticky. at that point salvage the poles forva diy project n set it out to sea.

btw some tent manufactuers like big Agnes will honor their warrantee n give credit for the tent price.

the deteriorating pu was a defect in material.

[Time Zone]

Thanks for your reply!

But I think you may be mixing up a couple things. The seam sealer on the outside would be significantly newer (by years) than the failing seam tape on the inside. So its "internal clock" of aging would not be starting at the same time. But I do agree with you, once the odor sets in, it's done for ... and I would salvage the poles for future DIY projects.

As for deteriorating PU being a defect in material, it's my understanding that it is a natural chemical process that inevitably occurs with age and conditions (usage and storage) - not any more of a defect than rust on a car in Michigan. Granted, it can be done better or worse, but eventually it'll occur. I suppose if it occurs unusually soon, that might qualify as a defect.

[Franco]

Some people think that PU coated maerial should be stored loosely so that the fabric can breathe (outgassing). The idea is that that if the gas is trapped it will cause the damage. This is from people that had their tent stored tight inside the stuff sack after the tent was fully dry.

[Time Zone]

That would be interesting if true, esp. since tents are not stored loosely before being sold, while sitting on the shelf. I have heard similar advice, but have never seen that guidance provided by a tent maker.

[camper10469]

haha I seam sealed the outside of my very old tent fly n the seam sealer eventually turned white n peeled right off in less than a year.

check the warantees n email the companies anyway... I was credited $399 of a 8yr old BA tent that got stinky n sticky. I emailed BA n they gladly gave me the credit... I bought the copper spur for a few more bucks with my credit... I also love the newer materials they use too

Kely gave me a new fly for the same complaint of PU failing. That tent, Kelty Clark, was 6 years old.

An Osprey backpack PU failed after 6yrs n they replaced my backpack with a brand new one, no color choice but a much better version.

[Time Zone]

one year follow-up ...

The seam tape on my trekking-pole supported tent is peeling extensively. To me this was notable because this tent apparently used PE (polyether urethane) coatings, not PU (polyester urethane) coatings. PE was supposed to be better. If so, in my experience, it's not by much. Perhaps failure begins at 5 yrs instead of 4. [though admittedly, that's after purchase, not necessarily after manufacturing - my tent may have sat for a year or two unsold before I bought it. And, I don't store my tents loose, as I do my bags and quilts. I store them dry, but in the bag they came in].

I'm going to look harder at sil/sil offerings, even if I have to seal it myself.

[peakbagger]

Dont forget Dynema Fabrics, very expensive but the seams are welded.

[Time Zone]

TIL I was supposed to store the tent loosely, not in its stuff sack Storing it dry is not enough. So ... it's on me.

Oddly, I have some other PU coated gear (a tarp, a WPB bivy) of roughly the same vintage that is doing fine in their stuff sacks. The only difference I can figure is that their sacks are more generously cut ... you don't have to wrestle the items to get them in there. Going forward, if I have a tent that comes only with a tight stuff sack, I'm going to try to store it in an old pillowcase instead. I guess all this loose storage of bags, quilts, and tents will help control "gear acquisition syndrome" - one has only so much closet space! I wonder if under-bed storage is a viable option ....