Cuben Fiber – Q&A

[Scott Peterson]

Bill, I am very glad that something so negative in your life has turned into such a positive for you and others…and I wish you continued health and hope that you can rejoin the trails soon.

Sorry for the thread hijack…this is afterall supposed to be all about the Cuben. Did you hear Columbia is coming out with a line of kids Daypacks made out of Cuben???

[Bill Fornshell]

Scott, Thanks,

Thread hijack – not to worry.

“Did you hear Columbia is coming out with a line of kids Daypacks made out of Cuben???”

No, that is very interesting. I will have to look at their web site and see what they look like and what they have to say about the Cuben fiber.

[Bill Fornshell]

“Did you hear Columbia is coming out with a line of kids Daypacks made out of Cuben???”

No, that is very interesting. I will have to look at their web site and see what they look like and what they have to say about the Cuben fiber.

I checked the Columbia web site and didn’t see anything and then called them. The person I talked to didn’t know anything about it but also said that it might be something coming out that really hasn’t been announced yet. Where did you hear this?

Thanks.

[Scott Peterson]

Ooops. I was making a funny. Obviously not too funny. Sorry for the wild goose chase!

[Andrew Browne]

Bill, would Cuben be suitable to make a lightweight hammock from?
If so what weight material would you suggest?

[Scott Peterson]

By the way…Jason at Cuben did kind of indicate that some established manufacturer somewhere was inquiring about the material. It seems those guys need a sales/marketing person to visit a couple manufacturers to show them what is up. Right now they probably don’t see money in it compared to their core users…but if a big manufacturer used the stuff it could become relatively significant and totally incremental business for them.

[Bill Fornshell]

Andrew asked:

Q -1. Bill, would Cuben be suitable to make a lightweight hammock from?
If so what weight material would you suggest?

A – 1. I am working on this as we speak. My hammock will be an intergrated Hammock/Total Sleep System, I call it my Floating Bivy. In the past I used silk for my hammock. The silk hammock material for me at about 157 pounds is about 0.6oz a sq yard. It is much cheaper and about as light as a hammoch made from Cuben. My hammock is a custom made silk Ed Speer Hammock and has no sewing except the velcro along the sides. My new hammock design needs to be sewn across the width of the hammock and I am afraid the silk might tear on the sewn line. I want to try a 0.66oz per sq yard Cuben but have to wait till they make some more of it. Might be a month or so.

What style hammock do you want to make? That would decide for me what fabric I used.

[Eric Noble]

Andrew, I have no experience with Cuben. I can guess that breathability may be an issue if it is used on the bottom. I have a Hennessy hammock and the bottom is breathable. People who have put materials that don’t breath, such as space blankets, underneath them in the hammock have found that moisture can be a problem.

A project I am eager to start, is to replace the Silnylon fly of my hammock with one made out of Cuben. I think Cuben would provide all the benefits of Silnylon at far less weight. The recent talk of taped seams now has me wondering rather I should sew, or tape the seam that will go down the middle of the fly were the ridge line is. Has anyone done both, sew and tape? I would hate to have the ridge line seam fail in any way. Also, does the lack of stretch of Cuben obviate the benefits of a catenary cut?

[Bill Fornshell]

I used the 3M tape (9485PC from Kitebuilder) and then had to sew something over part of where the tape was. This was a sticky mess. The glue would stick to the needle on my sewing machine and I had to clean or replace the needle often.

If you mean sewing through the glue – along the same line where you glue – I would not do that.

One thing I did with the tape was cut it in half so it wasn’t as heavy. This worked but it was not in a stress area.

[Eric Noble]

Unfortunately that is exactly what I was considering. A flat-feld seam with the tape used to initially join the 2 overlapping pieces of material, folded and then sewn through. I thought the tape would seal the holes.

Since seam sealing is a little bit of an unknown, I am now leaning toward taping, but am concerned about the strength of the seam.

What is your thought on the use of a catenary cut with Cuben? Is it needed?

[Steve Peterson]

I regularly sew through the tape I use and my needle doesn’t get very gummy at all. Bill hasn’t said what exact tape he’s using, but if it’s the 9460PC stuff, maybe it’s gummier.

If you’re in doubt as to the strength of a taped seam, why not do what I did: make a small test piece and load it up to prove to yourself whether it is strong enough or not.

One more tip if you tape: let it sit for a few days before you put any real load on it. 3M says (at least for the stuff I use) that the bond increases its strength with time.

[Eric Noble]

Thanks Steve. Have you felt the need to seal the seams you have sewn through, or do you feel the tape did the job?

Getting stronger with age. I like the sound of that. I wish it applied to me.

[Steve Peterson]

I didn’t sew my tarp–it’s all tape, so seam sealing wasn’t an issue.

When I do sew something I want to be water tight, I put it under load for a bit by just pulling hard by hand and *then* seal it because the stitching (at least as I do it, on the material I use) will, when stressed, slightly open the holes the needle made. Seam sealing after stressing the seam allows you to fill those holes. It *might* work to seam seal before putting it under load, but I’ve never tried it.

[Andrew Browne]

Thanks Bill
Considering making a hammock along the Speers design, I weigh approx 200lbs and 6’1″ height

[Bill Fornshell]

My tape is the 3M number 9485PC from Kitebuilder. (I have addedthat information to my post about the tape) I have two rolls, one from Kitebuilder and one roll from a local 3M Dealer. It was a little cheaper at the 3M dealer.

[Steve Peterson]

Bill, I think I see why your needles gum up and mine don’t–your tape is 5 mils thick and what I use when I sew through it is only 2 mils thick. The 9472LE is the 5 mil stuff I use for structural seams and the 2 mil stuff I use for holding parts in place while sewing is designated as 9471LE. Also, the adhesive type used in your tape is different from that used in mine, so that might also contribute to the difference in needle gumming up.

Incidentally, the reason I use these tapes is the guy at 3M’s technical help desk recommended them. I didn’t exhaustively quiz him on the differences between the various adhesives, figuring I’d test the tape out myself anyway, and call him back if it didn’t work out. So far I’ve had no reason to call him back.

[Steve Peterson]

If you go to the Cuben site and look through their offerings you’ll see a bunch of numbers like CN1K.08 together with weights in units of ounces per sail makers yard (which is not 36×36). Bill lists the materials he uses in terms of weights per square English (36×36) yard. You’ll have some trouble translating between the two and eventually when you talk to Cuben, you have to use their designations. Maybe Bill can fill in the part numbers for his materials.

As for me, all my stuff has been the CN1K.08 stuff. Which, just to confuse the issue, is sometimes referred to by the Cuben folks as CT1K.08 (go figure). This stuff weighs about .65 or .66 oz per square English yard. I’ve always bought “ends” which are pieces shorter than 9 linear yards–they offer a 10% discount on these pieces.

[Leonard Rice]

I’ve never used cuben, but you might try cuting it with a rotary cutter. Available in the fabric section at wally world or other such store. Make sure you get a cutting mat to go with it, it will make your blade last much longer. I have cut every thing from saran wrap to 1/4″ leather with outstanding results. They’re easy to cut curves with, and you can cut straight lines by running them right down the side of an aluminium yardstick. There are varying grades/prices, The brand name of the better one is Olfa.
http://www.olfablades.com/rotary/index.html

Does the tape make the seam a bit more ridgid? I am looking for an easier way to sew these “slimy” fabrics together so that my seams dont look like crap. I’ve been toying with the idea of taping the seams then sewing through the taped seams. But I dont want to wind up with something that reduces flexibility or creases in the same place repeatedly when you stuff it in a sack. Any ideas?

[Steve Peterson]

Thanks for the comments on the rotary cutter–I have seen them but didn’t know how well they might work on something thin/flimsy like cuben. I’ll look into them some more. One issue I’d have is replacement blades–cuben seems to dull cutting edges pretty quickly.

Re taped seams being stiff: I use taped seams in my pack bags and dry bags, both of which have roll tops. The seams are only slightly stiffer than the rest of the material–the seams do not in any way interfere with the roll tops. I don’t sew through those particular seams.

[Michael Martin]

Hi All-

I’ve been following the “taping” thread with interest for some time in the hopes that it might save me from my meager sewing skills. ;)

I wanted to pass along some info I recently got directly from Cuben Fiber:

They recommend 3M 9485 or Dimension Polyant Ultra Bond adhesives for permanently gluing their products. In fact, they carry them! I don’t have any experience with either of these; I just thought this might be useful to someone, as several different adhesives were previously mentioned.

Cheers,

-Mike

[Joe D’Paz]

This is a real cool posting…I’ve been wanting to make an ultralight hammock under 1lb. and a multiday pack under 6 oz. I like the Hennesy ultralight asym but I want it less than 1 pound and it seems than cuben might work.
I was wondering if anyone is used this tape….1,000 M.P.H. tape: The U.S. Navy uses duct tape to repair radomes. A Radome is the dome that fits over a radar antenna. On an airplane, that’s usually the nose cone. It has to be transparent to the radar waves. (Any repairs must be radar-transparent, too on fighter aircraft.) Since the planes fly so darn fast, they call it “thousand mile an hour” tape.

[Steve Peterson]

Back on 2/26/2006 I indicated that I would try to post some photos/text describing my Cuben Fiber projects. I’ve been mighty busy prepping for my PCT thru-hike, but I’ve found a bit of time to throw together some stuff. The tarp is here.

The pack is here.

I’ve made separate threads for these in MYOG because I anticipate some questions/discussions. I’m repeating the links here for the sake of completeness.

In my 2/26 post I mentioned a drybag. This is made exactly like the bag for the pack, except without all the pockets and other stuff, so there isn’t a separate article for it.

Hope this gives people some ideas.

[Leonard Rice]

I have been having problems w/this stuff. It doesn’t seem to like tafeta at all. some times when it is comming off the roll it sticks to the kraft paper stretching the adhesive out and making a general mess. What fabric does it seem to work best on? Has any one else had these problems or did I get a bad roll?

[evan parsons]

Hi there-

I was curious, Bill, and everyone else, how Cuben “breathes.” What type of fabrics does it compare to in breathability?

And while we are on the subject, I would like to confirm that it is about as waterproof as silnylon and close to as durablew as a light ripstop?

Thanks for all the posted input so far, all very valuable as I dive into this new material.

And I appologize if this question is repeditive, I may have missed this bit of info in the other posts.

Evan

[Benjamin Smith]

Evan,

I think if you browse back through this thread, you’ll find that there are too many varieties/weights of Cuben to answer your durability question directly.

From what I understand, it is not breathable – think a mylar space blanket – but is very waterproof.

Ben

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