RugRat nylon vs polyester when wet video

[@AndersRamm]

So why are also high end tents outer fly still made out of nylon?

[@Thetentlab]

Hi Anders, Weight is the simple reason. The absolute lightest tent fabrics are nylon. They go down to 5D (or is it 7D? - denier information has disappeared from tent descriptions) AND at least one fabric supplier has mastered extraordinarily precise, low weight, coatings. Polyesters fabrics are made by other suppliers down to 20D and they have NOT mastered coatings as well. The result is that you can get a nice 20D non-coated fabric for a tent but the coated fabrics below 30D are not reliably lighter weight than 30D. It makes no sense but there's something in their coating process that sabotages the finished weight.

[@agustinmorales3888]

Buddy, l have to say you are the best. Looking forward to get the 4 person version.

[@Thetentlab]

Nylon and polyester can be made into fabrics with identical weights. Generally the weight of a fabric goes by Denier and thread count. Identical Denier and identical thread count should make the same weight fabric assuming everything else is constant (which, in practice, it never is exactly).

[@dalejuhl8591]

Thank you for sharing - Nylon is absorbent, this is a good thing to keep in mind when making selections

[@julieheim]

Does this mean the Nylon will leak?

[@dalejuhl8591]

@@julieheim No treated nylon won’t leak for years it will absorb water and will stretch and sag Polyester doesn’t and is not absorbent Nylon is stronger and nylon is more expensive

[@userdpua]

Great job. As I understand, nylon is more durable, so generally, 15-20d nylon tents are 15-20% lighter than 210t PU, w/o losses strength.

[@mikececot-scherer2232]

The generality you mention is not about polyester versus nylon. It's 210T 70D versus lower denier fabrics. Comparing tent fabrics that are on the market in tents for sale, the 70D fabrics are more durable and heavier. If you could make a tent fabric from any yarn you wanted, the high tenacity polyester available from Japan would beat any similar weight nylon yarn in performance. It very much comes down to what fabric makers have chosen to offer. Without widespread knowledge of how awful nylon is when wet, nylon tents sell fine.

[@sunesnigel]

@@mikececot-scherer2232 but wouldn't a 70D Silicone nylon be heavier then a 70D polyester?

[@ricecowboy]

I believe there are SilPoly products are the market now.

[@Baasicstuff]

Yes the MSR Freelite Rainfly is 15D ripstop nylon 1200mm Durashield™ polyurethane & silicone and the MSR/Body is

[@AlSaifuddin]

Thank you very much for all your efforts

[@pedroclaro7822]

Awesome video! Short and concise, shows exactly what the title says it would. I'm going for a tarp and this might not be a problem for me, but I'll likely have to use elastic shock cord on all guy lines and stakes so that the tension on them counteracts water expansion (at least partially), so that it doesnt flap around making noise, or worse, create water pockets weighing down on the tarp.

[@MikeleKonstantyFiedorowiczIV]

so what is better?

[@Sam-sw2ix]

I don't know.

[@JamesKeltan]

Nylon is stronget but sags when wet. Poly is les stronger havier but bettet against uv and dosnt sag as much when wet

[@MikeleKonstantyFiedorowiczIV]

nylon all the way or mix poiliester/nylon poliester is weak@@JamesKeltan

[@keven8047]

​@@MikeleKonstantyFiedorowiczIVno no no it depends on the goal....

[@MikeleKonstantyFiedorowiczIV]

@@keven8047 from my experience nylon is best or nylon/poliamid 50% and poliester 50% is best. 100%polieter is always low quality and durability material. Nylon all the way.

[@FRCVIDS]

Wait, no silicone treatment for polyester? What is silpoly?

[@Thetentlab]

No, that sample didn't have silicone used in quite the same way as sil/pu nylons of the time. It had a liquid silicone water repellency treatment (silicone DWR, very common) whereas "sil/pu" usually means that there are silicone solids impregnated into one side of the fabric and a polyurethane coating the other. That has changed since this video. Now we have basically the same finish available on either (neglecting that all finish details are considered proprietary by the fabric supplier so we can't be sure that ANY finishes are actually identical from one supplier to the next).

[@Baasicstuff]

@@Thetentlab MSR uses this DWR coating

[@jacobnie3865]

Which one is heavier?

[@Thetentlab]

The two rainflies in the video are made of the same denier (20D) and have the same sil/PU finish. So the fabrics were as comparable as I could ask for. As to the final weights, the polyester rainfly has all our features - windows, vents etc. - and the nylon one is bare-bones (to spare the sample makers all the details) so the finished fly is heavier. But because I did that, I also had no way to get an exact comparison of the fabric weight itself. At any rate, the point of this video was to show how nylon sags when wet and how Polyester doesn't. That property is universal for all fabrics weights (it's even true for lightweight cords and heavy webbing).

[@manjichromagnon5480]

This is remedied by using elastic loops

[@mikececot-scherer2232]

Actually, it's not. There are two issues: the fit of the rainfly panels to the tent structure and the poor wind performance of elastic guylines. When a nylon fabric panel grows 2-3% it means that it no longer can fit the pole spacing of the tent underneath. For a simple pointy-topped triangular tent it could still work because a bigger triangle pretty much fits over a smaller one with the same angles. But most tents are more like domes or A-frames and a bigger dome or A-frame doesn't just pull down to fit on a smaller one - all the corners overhang the poles. Even if you go through the hassle of pulling the rainfly bottom edge out, unclipping the fly bottom from the tent and staking it out separately from the tent floor, loose areas on the upper fly form which can pool water or snow on the outside and drip condensation on the inside. The wind performance of elastic guylines is particularly poor. Essentially your tent looks great until the wind pushes on it; at which point the elastic stretches and the fabric catches the wind in big scoops. So the elasticity wrecks the aerodynamics of the tent. The result is like having your rainfly come alive like mad animal that violently thrashes, snaps and shakes. It's not at all nice to try and sleep through. All this bad performance is something you won't put up with once you use a polyester tent. It's hard to overemphasize just how calm, stable and concern-free they are. Having used them for many years now, it still astounds me how they look immaculate and perfect through all kinds of weather without even an adjustment required. There's no drama, they just sit there...

[@ianstiehl1994]

For tarps it works though. I don't use elastic loops though. Silnylon stretches even without being wet. I just cinch down my timeouts one extra time before I go to sleep. Works every time.

[@Zz-mo4gm]

What tent is that?

[@Thetentlab]

That's our (TheTentLab's) MoonLight 4 tent.

[@turboturd7954]

Very helpful video, thx