Cuben Fiber Meet My Tensometer!

Chris. I got a full roll of some cuben tape. I got it with some tarp from gear swap a while back. Im never gonna use it so if you pm an address Id be willing to ship it for testing.

{Off_Topic}
Ok, I searched the support forums and can't find an answer: I've tried both my personal and professional email addresses but the BPL site thinks they're bogus and won't let me PM people. Am I doing something wrong or is it simply broken?
{/Off_Topic}

Chris,
If no solutions appear this evening, submit a formal help request. The back office will get it resolved fast.

Look to the upper right and click on Help, then click on My Support. It appears to be for the store and ordering, but it Is the route to quick resolution for issues like this.

Though I see your point, my vote is still for CT2K.08 as the best all around cuben laminate. All .08 products use the same weight film, so the extra weight is added Dyneema fibers. I personally don't think there is any sense in using a material that is weaker then silnylon. Silnylon has an average break strength around 70-80lbs/inch which would be stronger then everything except CT2K.08.

Material Weight Break Strength Warp
CT0.3K.08 11.4 grams/ms 35 lbs/inch
CT0.6K.08 15.8 grams/ms 60 lbs/inch
CT1K.08 17.4 grams/ms 68 lbs/inch
CT2K.08 25.4 grams/ms 105lbs/inch

What is everyone else's thoughts?

> my vote is still for CT2K.08 as the best all around cuben laminate.

Ah – but is it the best? We won't know if we don't measure it! So, I vote for a wide range of tests on the most common (CT2K.08?), but I also vote for *some* carefully selected tests on a wide range of other weights.

"I often say that when you can measure what you are speaking about, and express it in numbers, you know something about it; but when you cannot measure it, when you cannot express it in numbers, your knowledge is of a meagre and unsatisfactory kind; it may be the beginning of knowledge, but you have scarcely in your thoughts advanced to the state of Science, whatever the matter may be."
Lord Kelvin, speaking to the Institution of Civil Engineers, May 3, 1883

Cheers

Hi Chris,
I am most interested in CT2K.08 but I am also interested in CT1K.08. As well as testing seams I would be interested in testing Tie Out designs.

Okay well let me just do this for sample submission. Neither my employer nor the address of my employer is a secret so we might as well route all samples there. Anyone who cares to contribute fabrics, tapes, or adhesives can send them to my attention to:

Attn: Chris Lucas
2000 NW 88th Ct
Miami, FL 33172

I'll try to sort out my PM issue but this will allow work to proceed in the meantime.

EDIT: PM issue has been resolved.

I've pulled the data on the lightest fabrics from the specification sheet, massaged it slightly, and placed in a more aesthetically pleasing format.

Cuben Fiber Data

Point of curiousity; does Joe at ZPacks refer to weight in oz/m² even though he states oz/sqyd? I don't find any fabric weights which are 0.6 or 1.5 oz/yd².

I think most users/companies are manually calculating the weight in oz/yd since that it is more easily compared to other materials, which are usually spec'd in oz/yd. This seems to clearly be the case with CT2K.08 which is referred to on this forum and by manufacturers (ie. MLD) as 0.7 or 0.75.

I'm not sure what was/is happening when people/companies refer to 0.6oz cuben. Most references to 0.6oz cuben are older so maybe it refers to a style that is no longer available? Or maybe they were referring to CT1K.08 which is roughly 0.6oz/meter and they were incorrectly using the term oz/yd?

In the case of Joe @ Zpacks, I think his '0.6oz' cuben is CT2K.08. My wife has his cuben packcover and I used that to make a replica in 0.75oz cuben and my pack cover weighs 29g vs. 27 for the Zpacks one, so I think it's safe to say that the same type of cuben was used. Almost all of the weight of my 0.747oz cuben packcover (~23g) is cuben, so if Joe's cuben was really the next lightest cuben (CT1K.08) then you would expect a more dramatic weight difference than 2g.

On another note, I think the lighter variations of cuben should get more attention then they are getting now. 0.7oz cuben is getting all the press but the lighter versions are great for some applications too. For example, I have a 0.34oz cuben stuff sack that I use for my clothes and I has been holding up excellent for me with zero signs of wear through 20-30 days of hiking so far this year. Too bad I seam sealed it and nearly doubled it's weight from 7g to 12g.

It's nice to learn that .08 refers to the thickness of the film and then the '2K' or whatever refers to the amount of dyneema strands. In low strain but higher abrasion applications it seems like a lighter weight of a cuben would work just as well as CT2K.08. For example, a 0.34oz cuben groundsheet may hold up almost as well as a 0.74oz groundsheet, since the abrasion resistance of the film is the main factor. In applications where you are straining the fabric highly (ie. tarps) then you'd probably want the higher dyneema count.

Hi Guys,
At my sail loft we are about to built a 900sq/m cuben spinnaker. It is for one of our Supermaxi (100') customers. We will be using cn5 and cn9 (high biased).

We are one of the few lofts in the world that builds these, and we've built many. Construction is simpler then you think. I will try to cover all steps of production in a simple way.

I'll start a new thread soon.

Many may not know this, Cuben Tech is owned by North Sails. We needed the technology to develop another product 3Di (worth a google).

nick

We are one of the few lofts in the world that builds these, and we've built many. Construction is simpler then you think. I will try to cover all steps of production in a simple way.

That would be great!

Now we are focused on cuben seams. However, I think that one critical aspect we are overlooking is that cuben has a great strength along warp and fill, but less (how much?) at bias. In many applications you simply don’t have forces in just one direction (think the guyline attachment points of a shelter).

I see things like tri-radial spinnakers, laminates with yarns at various orientations… all for multi-directional load handling.

Sure we don’t have the money nor the tools of yatchies, but if we learn how to design more efficiently, we can make shelters with lighter versions of cuben than today.

>On another note, I think the lighter variations of cuben should get more attention then they are getting now. 0.7oz cuben is getting all the press but the lighter versions are great for some applications too.<

I want to second Dan's point. I have two tents made from CTO6K.08 and my experience so far says this material is adequate for at least 3 season tents. I think it is going to be more about design details than the raw breaking strength of the material.

I can contribute some samples of this material if you don't already have it.

i also have some colored material in the .48 and .74 weights if it is worth testing to see if the process of adding color changes anything (i'm sure it doesn't but again, i know nothing in this area)

-Tim

I am sure my ignorance in this matter is about to show itself yet again, but i'd like to see in the article tests of fabric who are unmolested and ones who have been crinkled and stuffed then unfolded. My thought is it would show affects on the fabric from stuffing vs. folding and if there is a reason to do one method over the other. Again, i totally realize that this may be useless and i know it comes form me, and i'm totally uninformed when it comes to this side of things. I just sew them.

-Tim

> but i'd like to see in the article tests of fabric who are unmolested and ones who have been crinkled and stuffed then unfolded

A very good suggestion in the real world.

It's entirely possible that folding Cuben causes pinholes to be created in the laminate, and these might act as tear initiation sites, thus weaking the composite fabric. As we know from experience, mylar shreds very quickly once a tear has started, which is why simple polythene bags are often preferred over 'space blankets' for real-world survival bags that have survive exposure to thorns and wind.

Not sure if y'all know, but there is a new product, CT3.5K.08 available. Pretty much lands square between CT2K.08 and CT5.08. Just wanted to update everyone.
g/m2 = 35.4
Warp break (lbs/in) = 149
warp load @ 1% = 50

Looking forward to the results of all the testing! Thanks to everyone that is collaborating, def benefits all MYOGs.

EDIT: So that is 1.044 oz/yd2

"I think that one critical aspect we are overlooking is that cuben has a great strength along warp and fill, but less (how much?) at bias. In many applications you simply don’t have forces in just one direction (think the guyline attachment points of a shelter)."

Yes we still have a lot of research ahead of us. Almost nothing has been done using high bias cuben in backpacking applications. 'High Bias' cuben has additional dyneema strands at +/- 45 degrees in addition to the stands at 0 and 90 degrees that regular cuben has. Using high bias cuben might be a safer way to go, as regular cuben is very strong when pulled in some directions but not as strong in others. High bias cuben doesn't stand out on the spec sheet as offering as great strength for the weight, but it might excel in the real world as it may not have the same vulnerabilities.

CT0.6HBK.08 could be an amazing fabric at 0.8oz/yd that is strong regardless of what direction it's pulled in.

Geez….we should setup a few group orders of cuben so we could all get a few yards of each type :)

The visual difference between regular and high bias cuben is very distinctive. High bias is much more opaque, with much more thread in the product.

The designer's at work all recommend that I use this over regular cuben for my tents. But… It only comes in heavier weights, thus rendering the major advantage of cuben nil.

Have heaps of high biased cn5, cn9, cn13, cn20. But would you test something you never use for these applications?

nick

CT0.3HBK.08 is 17.4gsm and High Bias (.51ozyd2 right). But it is $34m vs $21m for the CT1K.08 which is also 17.4gsm.

-Tim

Hi Nick

> But would you test something you never use for these applications?
Well, possibly, just to see what the periphery of the Cuben space looks like. Any samples of any versions you can contribute to the project will be greatly appreciated. Same for anyone else of course.

Cheers

I'm quite happy to smash, snap, poke, prod, pull, and bend anything we can think might be interesting. The tensometer is only too happy to punish the poor unsuspecting samples and the tests themselves are very fast.

Hey Chris,

Would you test one of my proprietary bonds against one of the other kinds of bonds? The bond is incredibly strong while being easy to apply. In a 90 degree peel and a 45 degree axial peel it will completely delaminate the cuben fiber laminate even past a CT5K.18

You know I will. Recommend you send three samples of each rather than just one.

Not sure where you are at with material and adhesives, but let me know what you need and I can send it down. I've got loads of scrap 0.33 and 0.75 (in yellow!). I also have the sample pack from Cubic tech which contains all the various fabrics, plus some ones that aren't even on the price list. I would guess from memory that they are about 8" X 8" in size.

With regards to adhesives, my only concern is that the 2 tapes I tried a while back are now rather old so might not be the best choice but I have a hysol tube and a venture 1163 tape that is very fresh. I have several other industrial adhesives that didn't work out, but of course you are welcome to them.

A third party test of Lawsons technique would be cool, and will give us an idea of what is possible. I wonder if any of the other cottage guys are watching this thread. Do you think Ron Bell or even BPL want to provide a sample bond to be included in the testing? What about testnig some sewn strips? I'm curious if there is a point at some thickness where bonding wouldn't be beneficial. I could go on and on…

I think you're gonna have your hands full on this one :), don't be afraid to ask for some help. There are going to be LOTS of people interested in this.

..Oh yeah, almost forgot. I'd love to see a bunch of cuben versions tested, but of course I have a special interest in the lightest ones.

I will send you 100 samples if need be.

Good points Steve.. In addition to everyone else's stuff, I have a tube or two of unopened still in the packaging Hysol that I will donate for testing along with any tape or cuben material you need. Everything is new so it should be good to go.

You should create a list of things you have and things you need that way we can come up with a complete battery of tests for your article.

Cheers,
Lawson