Jan 22, 2011 at 7:41 am #1268059
I was thinking about a Pinnacle for winter camping- high volume, light weight- what concerned w/ is w/ fuel, water, food I'd be in the 30-35# range, more if I had to strap my snowshoes on
I've read about folks using a homemade frame sheet to add just a little stiffness to the pack, read one thread that recommend Sintra as a possible sheet
anyone try this? what did you use? did you just slip it into the hydration sleeve? how well does it work?
MikeJan 22, 2011 at 7:49 am #1686994Jan 22, 2011 at 8:59 am #1687016
Six Moon Designs has a frame and some individual stays that might work for you. They are both on this page:Jan 22, 2011 at 9:51 am #1687039
carbon fiber looks nice, but the plug & play six moon stays are a little more appealing :) I'd have to get some measurements on the GL packs, but sizing sounds about rightJan 22, 2011 at 10:14 am #1687047
1/10th in planking … weights ~4 oz …
allows me to carry 40 lbs in my mutant ….Jan 22, 2011 at 10:22 am #1687051
So elegant! Sometimes we work too hard at things. This board also provides some lateral stability. It also serves as back-up fuel for a fire so it would fit into the dual use forum. Hey, it's also a splint.Jan 22, 2011 at 10:29 am #1687052
darryl … its also a shovel for soft snow … a platform for yr stove … emergency stakes when broken up length wise … in an emergency i guess i could use it as a deadman anchor for tents … paint it orange before yr trip and its emergency trail signs material … put coating on it and its a writing board .. etc …Jan 22, 2011 at 11:36 am #1687063
eric- would have not ever thought of that :) is it attached to a torso nightlight?Jan 22, 2011 at 11:43 am #1687067
Look for door skins, with exterior glue.Jan 22, 2011 at 1:17 pm #1687095
Marc SheaBPL Member
Mystery Ranch uses .06 (1/16) HDPE for their frame sheets on their recreational packs. You can find some here http://www.usplastic.com/catalog/item.aspx?itemid=23869&catid=705&clickid=searchresultsJan 22, 2011 at 2:00 pm #1687105
^ thanks that gives me another option :) looks like the HDPE is more rigid than the Sintra, so you could get by w/ thinner, the Sintra might be lighter (little more porous) though?Jan 22, 2011 at 2:15 pm #1687107
mike … it just stufff it in the osprey provided pad … no need to tape it down i find
a zrest also works well
use 1/10th pine i believe it was …Jan 22, 2011 at 4:21 pm #1687147
te – waBPL Member
mike, i once used a plastic (ptfe?) cutting board found at REI for my frame.
using a pad much like Eric's, folded into thirds of 10" sections by 20" high it was then placed in my SMD Swift for a 6 day trip carrying 35lbs max.
id used it for what it is advertised as, a cutting board. cutthroat trout never tasted so good!
here's a link, http://www.rei.com/product/765776 although mine was definately not the 5.6 ounces as advertised. it is 7.6!
a little heavy for my taste. wont be using it again for backpacking.
the same idea can be applied however to a lighter version, but the support will be compromised. here's that lighter version: http://corplastics.com/2mmCorrugatedPlasticSheets.html
i found a "garage sale" sign at the hardware store, about 20×18" iirc and once trimmed down it worked perfectly, sandwiched inside that ccf pad o' mine.Jan 22, 2011 at 4:34 pm #1687153
Corrugated plastic sheet is a great idea. Some art supply stores carry it too.Jan 22, 2011 at 7:01 pm #1687203
thanks gents! I'll have to check the corrugated plastic stuff out- I can take a 4-6 oz hit if it helps w/ heavier loads :)Jan 23, 2011 at 12:54 am #1687277
i actually tried quite a few different plastics at home depot … i found that they worked for loads that were well packed in the 20-30 lb range … ie where you could get by with frameless, but the plastic sheet added a bit of stiffness … at the 40 lb mark i found the plastic concaving under the weight, especially if the load was not optimally packed
i also tried a few different woods such as fiberboard which had the same issue as plastic, balsa which was worked but was expensive, etc … the best is ultra thin, ultralight with the grain running vertically
with what i have now …. ive carried a belay jacket, a double rack of micronuts, double of regular nuts, single of offset, set of WC zeros, set of camalots, set of link cams, 1/2 set of TCUs, extra #3/#4/#5 camalots, set of tricams, 6 quickdraws, 8 trad draws, 2 screamers, anchor tat, harness, set of rock shoes, 3 L of water, lunch, guidebook, 60m rope
for the vertically challenged … thats something like 15-20 lbs of metal gear, 10 lb of rope, 7 lb of water, and 5 lb of other gear … about 40+ lbs total
and i throw it in anyway i want … and theres not a sign of frame collapse …. my knees however are another story =(
its all there except for the 3L of water. guidebook and lunch …Jan 23, 2011 at 1:24 am #1687281
"I'll have to check the corrugated plastic stuff out- I can take a 4-6 oz hit if it helps w/ heavier loads "
The plastic is light. You would need to add a lot of layers to get to that weight. Just a couple layers bonded together would be very strong. Silicone would be a good glue choice.
Google "twinwall sheet" too.Jan 23, 2011 at 7:56 am #1687324
eric- glad you're packing that and not me, of course you'd probably say the same thing w/ a boned out mule deer :)
I've done a little more looking at the corrugated stuff and see that R2 packs (defunct now???) used corrugated plastic and put small dia. aluminum tubes in it for their frame sheet (which were removable if you didn't need them)- Ace hardware carries a wide selection of aluminum tubing (I used some on my myog grill)
some are using brass tubes too
I'm starting to see the Sintra as a possible compromise between corrugated and HDPE, firmer than corrugated, less firm and lighter than HDPE- appears you can heat Sintra (like HPDE) as well if you wanted to put any forming into itFeb 4, 2011 at 1:29 pm #1692488
I used a cutting board for fabrics. The Blue or green kind. Ridgid, yet still flexable enough to contour some what. Cut it to shape similar to granite gear's topoflex and drilled holes every save weight. I think it was around 5 oz.Feb 4, 2011 at 4:13 pm #1692556
^ I'll check those out- is the type you're talking about?Feb 5, 2011 at 6:57 am #1692746
The one I used was much cheaper than those kinds. I think it was stiffer too. It is kind of like this one:
But I think I paid $10 tops.Feb 5, 2011 at 6:59 am #1692747
^ good deal, getting groceries there today- I'll have a look around :)Feb 5, 2011 at 12:05 pm #1692878
I've used 1/32 and 1/16" UHMWPE sheets from McMaster Carr, with vertical aluminum tubes (also from McMaster Carr) zip tied through holes in the sheet for added stability. The tubes dropped into a small webbing cup on the inside of the pack in the middle of the hipbelt. This has carried well up to ~60 lbs. I've also used ABS, which I think is a little heavier for the same stiffness.
Some general engineering considerations:
-increased tensile strength (a property of the material) means increased bending resistance
-I went with UHMWPE because it seemed to have the best ratio of tensile strength to weight (and cost…)
-corrugated anything will resist bending in the line of the corrugations better than a flat sheet (this is because of increased second moment of inertia)
-likewise a tube resists bending better than a rod containing the same amount of material (ie better strength per weight) for the same reasonFeb 6, 2011 at 7:08 am #1693137
I have some hdpe sheet coming, hopefully on Monday. I ordered some .062 (1/16") and .093 (3/32").
As soon as I get them cut to size I will post weights.
I will probably end up using the 1/16", but wanted to see what the 3/32" was like.
I also want to experiment with heat forming the sheets. Maybe the thicker sheet formed will be enough, compared to the thinner sheet with a stay for the trips where I need more support.
I am planning on sewing a sleeve on one to add an aluminum stay to see how it carries and how much more it would weigh.
I would like to have the option of just pad, pad plus sheet, and pad plus sheet with stay. Different choices for different trips.
I will let you knowFeb 6, 2011 at 7:16 am #1693139
^ yes, please do post up when you get a chance to mess around w/ it :)
the ability to use just the pad (light loads), frame sheet+ pad (medium loads), stay(s) + frame sheet + pad (heavier loads) would seem to be great solution!
heating the plastic and getting some custom contours would be really nice as well
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