I’ve had my Exped Lightning pack for over a year now, and I really like it. Lightweight, waterproof fabric, comfortable and able to handle somewhat heavy weights. My main concern with it though is that it isn’t seam sealed. Even though the fabric is waterproof water still gets in through the seams.
I sent an e-mail so Exped last spring, asking them if it was possible to seam seal the backpack. They responded and said that I could use seam grip to seal the seams.
I turned the backpack inside out, and put seam grip on all the seams on the inside. It wasn’t a pretty job, but since it’s on the inside of the back I really don’t care. I hope I got enough seam grip on the seams to make sure no water comes through. I did do this process last summer, but that time I didn’t use enough seam grip, and water still came through.
I always use dry bags for my sleeping gear and for my spare clothes / extra layer. But I still want the backpack to be waterproof so I don’t have to deal with the added weight of getting water inside the backpack. With the seams sealed I think I’m starting to get close to having a perfect backpack.