Hemming - how much strength does it add?

**onfire** · 05-06-2014, 04:41

Hello all,

I have slid quickly away from cheap(er) pre-made hammocks (such as the DD and Snugpak versions) and found that my own DIY ripstop efforts are both more comfortable and lighter. So far I have simply cut the fabric to size (generally 10ft x 60in wide) and then whipped the narrow ends before adding suspension.

I had a scrap of fabric fail on me when I used it as an impromptu hammock chair (unsuprisingly really as I simply knotted the ends and used slings to hand it from two trees before 'swinging' on it!) and someone posted that it failed because it wasnt hemmed.

I normally leave the fabric unhemmed along the long edges (as it arrived from the supplier / factory) but I do singe the narrow ends with a lighter to stop the fabric fraying before I whip it - is this significantly more likely to rip / fail / tear than if I hemmed all the edges?

Thanks, T

**Richard Tipton** · 05-06-2014, 06:02

I would "assume" that it's quit a bit stronger with a hem. It would make sense that a rolled hem, that is a triple thickness of fabric, would have at least triple the tensile and shear strength. Then again, I've been wrong before.

WV · 05-06-2014, 06:18

It's also likely that the thread you sew the hem with is much stronger than the threads in the weave (even the ripstop ones, if any), and you're adding two with each line of stitching, so it should be considerably stronger. The question is whether it needs to be, and that would depend on where it is stressed most - which may be at the edge when entering or leaving the hammock if it's whipped so the edges are tight. If you're going to fold the edge over twice to hem it, you might as well make the first fold 1/4" and the second fold 1/2", thus creating a channel in case you want to run a bungee through it for a side-stretch mod.

**onfire** · 05-06-2014, 06:55

Well that sells hemming to me then! Thank you.

I have another DIY to make and want to sew the channels for a knotty-mod and to hang it from the a dogbone rather than whipping it ... more significantly though, if I am doing the DIY process with other people then I want it to be 'bomb-proof'

**sargevining** · 05-06-2014, 07:24

I think the biggest thing hemming does is prevent separation at a frayed edge. For that reason alone I always hem the sides and ends of my hammocks.

**Ramblinrev** · 05-06-2014, 10:13

I will hem all the edges of my hammocks. While the selvage edge (from the factory) is very strong in most cases it is not always as tightly and densely woven as the main body of the panel. I have never had a piece fail if I didn't hem the selvage edge but I like the look of the hem better. You say you used a scrap of fabric for the failed seat. It may well be you caused the fabric is fray and/or separate at the edge. The selvage is intended to keep that from happening during the weaving and manufacturing. So if the edge is raw then most decidedly it must be hemmed. Otherwise... you pay your money and take your chances. In general, I like the look of the rolled hem.