Sleeping bag shell UV damage?

Have you contacted Marmot about this? I think most owners would report things like this to the manufacturer so, at least, they would be able to tell you if it's something that happens (and maybe why) or if you have a special bag that's possessed.

My home lighting has messed with the color (the above photos are closer to its vivid blue) but the multiple patches starting with the first professionally sewn one are clearly visible...that’s blue ripstop Kenyon tape. Good stuff, I’ve a patch or two on a Sierra Designs 60/40 parka that have stayed largely in place for decades.

I recommend Kenyon tape over Gorilla tape for a good piece or gear like that. Kenyon tape sticks super well and far more flexible than Gorilla or even Tenacious tape. It looks much better than Gorilla by far.

Had a Marmot Zeus tear at the back of the shoulder and my local outfitter sent it to !armot, told me a sewn patch was about 15 bucks. Marmot would not patch it and wanted $80 to sew a whole knew back panel. I said just send it back. Patched it with Kenyon and well over 10 years later it is the same as the day I patched it, looks good, tape all in place.

Yes. Nylon can do that with sun rays. It can also do that by pressing to violently hard on a baffle. That is why care is so important when washing it. Apparently stomping it in the dark ain’t so very good either.

Kenyon tape is ripstop nylon that is backed by a peel off paper. You do cut it and round off the edges with scissors. It is much lighter and less bulky than duct tape. It comes in various colors and a small role.

I keep a roll on hand but only take a small folded piece in my repair/FAK/fire kit, a very full service kit but still light and minimalist, here. The Kenyon tape is good for a small tear in a down jacket mostly. I don’t wear a puffy hiking but things still happen close around camp.



This is the full list of the kit;

Pocket Kit;
Mini Bic
Fatwood
Cotton ball
Ferro rod
Dram of tea tree oil
Cotton swab
Scissors
2x2” gauze pad
33” first aid tape
2 butterfly closures
Safety pin
Nylon upholstery thread
4 sewing needles
600 grit sandpaper
Duct tape
Kenyon tape
Allen key for BD pole locks
Mini compass

Here is a photo of some I’ve got on hand. I’ve used all my black Kenyon and need to get more.

I don't know if it's UV damage....it could be that the shell material is just getting old. I can't say specifically why, but I know that in Colorado, O-rings tend to crack and get brittle if exposed to the atmosphere...even if they're not left out in the sun. Ozone? I'm not going to pretend I know, but some materials just don't last that long. I have a TNF down bag that's been washed a few times, and is at least 40 years old, and it's still holding up well. YMMV.

Yep, that is a long exposure record fro any product, and I am going to assume at significant elevation.
I have lost or retired a number of tents and two packs from solar radiation, or I like to call it, sunstroke. No sleeping bags yet, but that may be because I have a fleet of different bags and none see that level of service. I have seen some old-timers sell their ancient bags for their fill to the DIY crowd. A lot of that pre-China down was premium Eastern European origin.