Which weighs more for CF… bonded or sewn + seam sealing?

Bryce,

You're asking for what we epidemiologists call the "counterfactual". Since one can't make exactly the same shelter twice with different kinds of seams and compare the weight (because the small difference in seam weight will get lost in the large variability in shelter weight), you won't get any quantitative responses to your question. You'll get differing opinions.

My opinion, for what it is worth, is that bonding is both stronger and lighter. When you bond, you add an extremely thin film of adhesive between smooth layers of mylar. When you seam seal after sewing, you add a comparatively large amount of adhesive to the irregular, perforated surface of a sewn seam. So sewing adds the weight of thread plus a relatively large amount of glue, while bonding adds only the weight of a small amount of glue.

As far as strength is concerned, I'd recommend reading the many posts in these forums about that. I think there is a growing consensus that bonding (done well) is much stronger than sewing, but others might disagree.

Thanks Colin for humoring me.

I posted too soon and only read a couple of very old BPL posts on the subject it seems. Back then people were more inconclusive.

Bonded seams it is!

Bonded for most seams works really well. In high high peel areas or places that need extra reinforcement you will need to bond then sew with a long stitch.. Adhesive choice is another huge issue. Best of Luck.

Here's a thread worth a visit. List some more here as you find them.

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=20093