View Full Version : whats the ideal material for h/m backpacks?
volks-man
05-17-2009, 10:55
what material would you use for a lightweight durable backpack?
my current external frame pack weighs in at just south of 5 pounds.
i would like to see that cut in half.;)
my idea is to make a single large compartment pack with top drawstring and cover flap, two water bottle pockets on the sides, one smallish exterior pocket, and a pocket on the inside of the cover flap.
the idea is to make it simple, light, and water resistant. i will be affixing a custom lightweight aluminum frame (perhaps several 3/16 aluminum rods)so that i may suspend the pack off my back with foam pads at both top and bottom (for air circulation):cool:.
what material would you use? any other thoughts or comments?
thanks.
v
fiddlehead
05-17-2009, 11:05
It depends if you want durability or lightweight.
I've hiked with people who have made their own packs out of canvas, cordova, rip stop nylon and even sil-nylon.
The sil will be the lightest (i believe his pack was around 7 or 8 oz) but he did wear a hole in it after a few hundred miles.
Good idea making your own gear. You'll get what you want and nobody to blame if you have problems of course.
Making it waterproof might be a challenge. That's why people carry pack covers or line their packs in garbage bags.
If you made the pack frame of light sapling poles, if they broke you could replace them. The pack might also be designed so that it could be worn with or without the pack frame. Sometimes it might be warmer and more comfortable to hike without the pack frame. Also, the frame poles might be used for other things, like tarp poles, or for hanging pots over a fire. Nylon and polyester are both pretty tough. I think way you do the stitching is most critical for durability, and also the way you pack it.
Here is a pack frame idea:
http://www.primitiveways.com/pack_frame.html
Obviously you might want to make it lighter and suspend it a bit higher maybe. The hip belt might be wide at the back, with the frame poles sliding into slots on the sides, and two narrow independant front straps and buckles in front. The shoulder straps might come down from a single point where the two frame poles tuck into slots forming a triangle. You could vary the length of you frame poles, depending on the season. The pack itself might be just a stuff sack, or a bivy bag packed with you gear and rolled up, or something custum made with pouches and pockets. Or there could be water bottle holders and a small pouches on the shoulder straps.
bigcranky
05-17-2009, 13:31
Here are a couple of resources you might find useful:
http://www.gossamergear.com/cgi-bin/gossamergear/myog.html
http://thru-hiker.com/materials/index.php
go to thru-hiker and look at dyneema. Its strong relatively light weight fabric thats very tear resistant.
McKeever
05-17-2009, 17:59
I've been making packs for 10 years. Spectra cloth is hard to beat but a very good pack can be made with sil nylon and a cordura bottom and shoulder straps.
volks-man
05-17-2009, 18:18
wow, thanks guys!
i think those patterns may come in handy.;)
the dyneema looks interesting. i assume it is very durable with the second layer runnin 45* to the other.
i am after durability. i want it to weigh nothing yet last forever.:cool:
spectra laced fabric looks promising too.... anyone work with that cuben (sp?fabric?)
the idea for the frame is less for supporting load than it is for moving the pack away from my back. i was thinking along the lines of a big "M" of aluminum rods welded together. the sole purpose of this frame is to support the body-side of the pack and keep it off my back through use of an upper pad and lower pad (3/4 thick foam). it would not protrude from the sides, top, or bottom of the fabric pack at all.
basically, think about your regular 'school book' backpack with my "M" frame and pads between you and the pack. shouldn't be real hard to adapt to existing pack plans...............
volks-man
05-17-2009, 18:22
I've been making packs for 10 years. Spectra cloth is hard to beat but a very good pack can be made with sil nylon and a cordura bottom and shoulder straps.
do you make them to sell or just for personal use?
care to share patterns?
do you ever use velcro for pocket closures?
thanks
v
Snowleopard
05-18-2009, 20:41
Cuben fabric -- expensive and light. Probably not nearly as durable as dyneema. One trick is to use a heavier duty fabric in parts of the pack that are more subject to wear and use something lighter for the low wear parts.
zpacks.com uses Cuben in his packs. He also sells Cuben fabric by the yard. questoutfitters.com sells Cuben also.
I haven't used it yet; it seems ideal for a tarp/tarp tent, but it's expensive.
go to thru-hiker and look at dyneema. Its strong relatively light weight fabric thats very tear resistant.
My suggestion as well. It's super tough and light. I have it on the bottom of my Golite frameless pack and it shows no signs of wear after approx. 400 miles (not much, I know, but no wear whatever).
Cuben, spinnaker cloth, etc. are for light weight (hyper-freaky weight) only, not for durability. They tear much easier than Dyneema or even basic nylon oxford (usually 2.5 oz. or more), but lighter (and cheaper) than Cordura. Usually those super light fabrics tear at the seam, the thread used to sew the panels together actually cutting the fabric).
atraildreamer
05-19-2009, 20:21
what material would you use for a lightweight durable backpack?
my current external frame pack weighs in at just south of 5 pounds.
i would like to see that cut in half.;)
my idea is to make a single large compartment pack with top drawstring and cover flap, two water bottle pockets on the sides, one smallish exterior pocket, and a pocket on the inside of the cover flap.
the idea is to make it simple, light, and water resistant. i will be affixing a custom lightweight aluminum frame (perhaps several 3/16 aluminum rods)so that i may suspend the pack off my back with foam pads at both top and bottom (for air circulation):cool:.
what material would you use? any other thoughts or comments?
thanks.
v
This sounds like the pack (brand unknown) that I got at a yard sale.
Why not find something similar and modify it to fitt your needs?
Blue Jay
05-19-2009, 20:32
Making it waterproof might be a challenge.
It has always astounded me why anyone would hike with a nonwaterPROOF pack, since water often falls from the sky. Light weight, durable rubber was invented quite some time ago. People continue to use garbage bags inside sponge material packs, very very weird.
It has always astounded me why anyone would hike with a nonwaterPROOF pack, since water often falls from the sky. Light weight, durable rubber was invented quite some time ago. People continue to use garbage bags inside sponge material packs, very very weird.
Lightweight rubber?
titanium_hiker
05-20-2009, 08:48
you don't have a waterproof pack because if water does get in it would pool at the bottom, meaning your sleeping bag and clothes would be sitting in water, and you'd need real good waterproof bags to put up with a prolonged soaking like that. Have you picked up a bolt of ripstop nylon in comparison with a bolt of PolyUrethane coated Nylon? PU is heavy! TH
My Jam2 is pretty waterproof. Hasn't been a problem yet but I think I agree that backpacks should be breathable, and have a drain at the bottom. I think the best thing to do is think about this stuff when you are out there. That is where the best ideas come from. Also, I noticed the Jam2 material was ok at -20F, but it didn't get a really good workout at -20F, or -30F. That's something to consider with some materials.
My Jam2 is pretty waterproof. Hasn't been a problem yet but I think I agree that backpacks should be breathable, and have a drain at the bottom. I think the best thing to do is think about this stuff when you are out there. That is where the best ideas come from. Also, I noticed the Jam2 material was ok at -20F, but it didn't get a really good workout at -20F, or -30F. That's something to consider with some materials.
The Jam2 is Dyneema correct? It seems to be the best compromise between light weight and durability with some water repellent tendencies as well at a reasonable price. Spectra is better, but WOW who can afford it? I have no experience with Cuben fiber, but I've read of failures so I am cautious about it. As for SilNylon, I like it's low weight and water repellent nature, but it is easily torn.
I am not sure that Spectra is better. I think Spectra is too stiff. I think the Dyneema is tougher because it has more give and stretch, and probably holds seams better also, pound for pound that is. I haven't tried Cuben either, but I've hoisted and hauled down and wrapped alot of spinnakers around forestays. Blown up a few also, and it does tend to go at the seams when it goes, but sometimes just boom, in too much wind. Very tough stuff for its weight. Good material for a UL pack if you build it and sew it and load it right. Dyneema is probably the better material though. Heavier, but still very light. I am not exactly sure what Dyneema is, but it feels like a rubberized nylon or polyester, because it has alot of stretch and give, which makes it very tough and durable. Stiffness is important for some applications, but not for backpacks I don't think. Toughness is more important. How much energy it can absorb. Also, by giving a little it spreads out stresses where threads go through the material at seams. Having a really good seamstress or sailmaker do the work would be a plus also, but why should they have all the fun eh. ;)
I am not sure that Spectra is better. I think Spectra is too stiff. I think the Dyneema is tougher because it has more give and stretch, and probably holds seams better also, pound for pound that is. I haven't tried Cuben either, but I've hoisted and hauled down and wrapped alot of spinnakers around forestays. Blown up a few also, and it does tend to go at the seams when it goes, but sometimes just boom, in too much wind. Very tough stuff for its weight. Good material for a UL pack if you build it and sew it and load it right. Dyneema is probably the better material though. Heavier, but still very light. I am not exactly sure what Dyneema is, but it feels like a rubberized nylon or polyester, because it has alot of stretch and give, which makes it very tough and durable. Stiffness is important for some applications, but not for backpacks I don't think. Toughness is more important. How much energy it can absorb. Also, by giving a little it spreads out stresses where threads go through the material at seams. Having a really good seamstress or sailmaker do the work would be a plus also, but why should they have all the fun eh. ;)
That is a good point regarding the flexibility inherent to the material. Maybe a Spectra bottom with Dyneema for the main body of the pack would be a good combo, allowing the wear resistance of Spectra with the flex of Dyneema.
Do you remember the old Kelty packs made from Spectra? Super light for their size, but expensive and an eyesore in white since it won't hold a die. I don't know if they have solved the die issue or not. I messed with one and I think you could have stopped a knife with that pack, but they didn't stay on the market long.
According to this, Dyneema and Spectra are both the same polymer.
Ultra high molecular weight polyethylene
http://en.wikipedia.org/wiki/Ultra_high_molecular_weight_polyethylene
Hmmm. I always thought Spectra was rather stiff.
My Go-Lite pack material has some give to it, at least initially. :-?
I wouldn't hesitate to use spinnaker nylon for a UL pack though, even a big one. Good stuff, as long as you build it and use it in such a way to spread the loads out. I'm not sure it would hold up to the sun or years as well though. Spinnakers do eventually get old and that's what really does them in. I wouldn't use it for a pack I wanted for 20 years, but a year or two for sure.
Allen1901
06-21-2009, 06:31
The 100% non-woven polypropylene used in the grocery bags stores like Kroger's sell, would make a strong, light, pack .
http://www.earthwisebags.com/index.html
Cheers!
cwayman1
06-21-2009, 15:01
you might could have a sil pack body with a dyneema bottom? the sil for water-repellence, and the dyneema to kinda help breathe/ drain and durability?
According to this, Dyneema and Spectra are both the same polymer.
Ultra high molecular weight polyethylene
http://en.wikipedia.org/wiki/Ultra_high_molecular_weight_polyethylene
Hmmm. I always thought Spectra was rather stiff.
My Go-Lite pack material has some give to it, at least initially. :-?
I wouldn't hesitate to use spinnaker nylon for a UL pack though, even a big one. Good stuff, as long as you build it and use it in such a way to spread the loads out. I'm not sure it would hold up to the sun or years as well though. Spinnakers do eventually get old and that's what really does them in. I wouldn't use it for a pack I wanted for 20 years, but a year or two for sure.
Kevlar is stiff. Spectra is not. Might have them mixed up as both were used for climbing (Kevlar is not anymore due to its tendency to shear off if used on a sharp angle).
Dyneema (The fabric used in the Jam has a pattern of Spectra threads running through it, used to reinforce the nylon fabric).
I have a prototype pack made by Mountain Laurel Designs out of silnylon. It tore at the bottom corner where the shoulder strap and mesh pocket meet. I'm sure the design has been updated and improved. I'm not complaining because the pack was given to me (free) by Ron when he moved his operation from the south up to Maine (I had ordered a poncho and bivy from him and he threw the pack in - quite nice). I may stitch it up and use it sometime, but my Golite Dawn is near perfect for all the hiking I do.
Rocketman
06-22-2009, 09:33
According to this, Dyneema and Spectra are both the same polymer.
Ultra high molecular weight polyethylene
http://en.wikipedia.org/wiki/Ultra_high_molecular_weight_polyethylene
Hmmm. I always thought Spectra was rather stiff.
My Go-Lite pack material has some give to it, at least initially. :-?
I wouldn't hesitate to use spinnaker nylon for a UL pack though, even a big one. Good stuff, as long as you build it and use it in such a way to spread the loads out. I'm not sure it would hold up to the sun or years as well though. Spinnakers do eventually get old and that's what really does them in. I wouldn't use it for a pack I wanted for 20 years, but a year or two for sure.
Carbon fiber is extremely stiff, when loaded exactly along the axis of the fiber. Much stiffer than steel, or an equivalent steel fiber. If you load it off the axis of the fiber, it is much less stiff. Technically, carbon fiber, loaded sideways or adross the diameter, has a low elastic modulus - one measure of stiffness.
Carbon cloth, made of carbon fiber is pretty flexible, although not as soft to the hand as, say, cotton or high strength Dacron. If the threads of the cloth are thick, then that will increase the stiffness in the hand (drape).
Fiberglass cloth is also capable of being draped, but the Satin weave of fiberglass cloth, and other satin weave correesponding cloths, is much more easily draped than the plain square weave.
Stiff is an imprecise term, and can lead to superficial contradictions when one mode of stiffness is compared to another mode, without taking the details into account. There is a specific effect of the weave geometry as well.
Johnny Swank
06-22-2009, 12:13
I've just used a 400-denier packcloth for our packs @$5.50/yd. 16 oz for the packs, and I've got several hundred miles on mine with no problems. By the time you beef up silnylon/cuben/etc, you're not saving all that much weight, and lighter packcloth is waaaay cheaper to monkey around with.
cwayman1
06-22-2009, 19:25
I've just used a 400-denier packcloth for our packs @$5.50/yd. 16 oz for the packs, and I've got several hundred miles on mine with no problems. By the time you beef up silnylon/cuben/etc, you're not saving all that much weight, and lighter packcloth is waaaay cheaper to monkey around with.
that's VERY true!
although, you can usually find decent deals on sil 2nds at outdoor wilderness fabrics :)