Cuben bonding tape

[John Gelack]

I just got a couple yards of Cuben Fiber and I'm intrested in starting a few projects. I would like to bond the seams rather than sew them. Can anyone tell me where I can get bonding tape from, is there certain brand I should be looking for. I know that ZPacks sells it, but I'm not sure that this is the right stuff. I appreciate any help you can give me. Thanks John

[Mark Fowler]

I am sure that Joe would not be selling tape for cuben if it wasn't any good. After all he does know "a little bit" about the material.

A standard tape for cuben is 3M 9485PC (Scotch brand). I bought mine from extremtextil in Germany as I was getting some other fabrics. Having a look at the photo on ZPacks site he is selling a 3m Scotch product. I am sure others will have alternatives.

[Ty Ty]

http://www.bearpawwd.com/misc_gear/misc_gear.html

[Dan @ Durston Gear]

Yeah the 3M stuff (3M 9485PC) is pretty good. I've used a few different tapes and this one seems to be the best. With that said, you do need to design your seams properly. You can still peel it apart after if you really pull on it in peel. Seams designed in shear will be fine, while seams designed in peel may fail eventually.

Peel vs. Shear:
http://www.backpackinglight.com/cgi-bin/backpackinglight/xdpy/forum_thread/32998/index.html?skip_to_post=291170#291170

The other thing to consider is weight. Tape is always heavier than sewing, so sew where you can and tape where you need to (i.e. main seams that need to be strong and waterproof). For a tarp, you'd want to tape the ridge line so it's waterproof and strong, but around the perimeter of the tarp you'd want to fold & sew, because this edge really isn't seeing any stress and using tape all the way around the perimeter of the tarp is going to add an ounce or so. If you're going to sew 0.51oz or 0.74oz cuben, then it either needs to be a seam that will see only minor stress, or it needs to be well reinforced.

If you're using heavier cuben (1.2oz or 1.5oz) then you can pretty much always sew unless you need a waterproof seam. As an example, 1-2 years ago I made a small stuff sack with 0.51oz cuben and 3M tape (1/2" width). It weighed 6.7g (0.23oz). I used it until recently when the cuben was pretty much worn out. Last month I made another one and I decided to use a bit heavier cuben so it lasts longer. I opted for 1.2oz cuben instead of 0.51oz, yet because I sewed the sack instead of bonding it, the finished product was actually lighter (5.0g or 0.18oz). So now my misc. gear sack is lighter and considerably more durable. Win-Win.

[Sam Farrington]

Dan,
Yes, but what was your experience with the added weight of Hysol urethan adhesive.
Could you tell how its weight compared to tape and sewing?

BTW, you sound pretty comfortable with sewing the heavier cuben; but what about the opening up of the stitch holes, as pictured in RJ's recent thread?

The reason I ask, is because bonding nylon strips to cuben where edges will be sewn may help with the stitch holes opening. But it would be helpful to know what adds the less weight, bonding or taping.

I also wonder what will stiffen the cuben less, the tape or the Hysol. The less stiff the material, the easier it is to integrate it into a sew seam, I think.
Your thoughts on this?

[Dan @ Durston Gear]

I'm sure the Hysol liquid adhesive added a decent amount of weight, but I never measured it. My rough guess was that about 2oz of the 10oz tent fly was probably adhesive weight. I'm really fuzzy on this now, but I think the entire tube of Hysol weighed about 3oz and I used most of it. Some weight may have left though as solvents evaporated…I'm not sure.

My guess is that the weight falls in between tape and sewing. The amount of liquid adhesive I was using seemed a lot thinner than tape does, but it'll never be as light as thread.

Using Hysol and then sewing later seemed to work pretty good. You just need to wait until the Hysol is totally dry or it'll gum up your sewing machine. It stiffens the seams a bit, but you could still probably do a rolled seam I would think. I've never sewn a seam after I taped it, but I wonder if the tape would stay fairly gummy for a while and thus be a bit of a pain to sew. Tape seems like it causes similarly stiff (ie. moderately stiffness) seams, but my guess is Hysol would work better if you're rolling and sewing later.

The heavier cuben variants (1.2oz and 1.5oz) are really amazing fabrics. For smaller stuff sacks (ie. pot sack, misc. gear sack) I would recommend using these variants because they are going to last forever and the weight gain is maybe 0.5g, which can often be offset by sewing it instead of bonding lighter cuben. You also want this strength for carrying heavy stuff. I've been using Zpacks Blast food bag for about 2 years now which uses 1.5oz cuben, and I've had that bag loaded with tons of weight (probably close to 20 lbs) and hoisted it up trees, dropped it, etc and none of the seams are visually stressing. For clothing and sleeping bag stuff sacks, lighter 0.51oz cuben is fine. I even use 0.33oz cuben for my clothes sack but that sack lives an easy life that is either in my pack or in my tent.

For most seams, I would just sew the heavier cuben using a simple seam. If it was a higher stress seam (ie. tarp ridgline, backpack shoulder strap attachment) I would probably fold/roll the cuben so that it's sewn through several layers. I think it's probably easiest and best to reinforce cuben with more cuben. Bonding on nylon might work, but sewing on nylon to cuben can cause trouble because the nylon has more stretch than the cuben. When you stress this seam, the nylon stretches and it ends up concentrated the stress on a smaller area of where it's sewn. My old SMD Refuge X tent had this probably with nylon reinforced tie outs.

That shot Ryan J posted looked like a lighter (ie. 0.74oz) cuben to me, but I'm sure you could do that to heavier cuben (or any fabric) with enough stress.

Here's a pic of the cuben tie outs I did on that tent fly last summer. It's 0.74oz cuben with the edges folded in and bonded, making it double thickness around the edges. Then I reinforced the corner with 2 additional layers of cuben (1 per side) by wrapping a piece around and the tie out is sandwiched between those layers. I ended up sewing this tie out later just because I couldn't think of a reason not too. But either way these tie outs are unbelievably strong…you could probably hang a truck off one :)

[Daryl and Daryl]

Dan,

Thanks for taking the time to give such a complete answer…..as usual. Very helpful

Daryl

[Sam Farrington]

Dan,
A most helpful post. Thanks for taking the time and sharing your experience.
I think you are dead right about the flaw in my considering bonding nylon to the cuben. Nylon separation anxiety may be at the root of it. I will just fold the cuben edges over and bond, as you did, and hope this will be gutsy enough to hold stitching, particularly where further bonding won't work well, as in the case of zipper tape and other non cuben materials. For edges cut on the bias (diagonally to the cuben fibers), may insert a strip of lighter cuben cut along the grain. Will experiment first. For tie out points, of course, still more reinforcement, as you did.

I think if the cuben is already folded at the edges, there is no reason to roll it into the seam with other materials (In my case, silnylon and Epic Malibu polyester). This will make it difficult to fashion the canopy by pinning, but an alternative way will be found.

Your comment about stitching through the bonding tape adhesive was also very helpful. Looks like I am going to have to grin and bear the Hysol. Was really looking for a cleaner alternative, though. First, will try GE sil glue on cuben scraps, just for the heck of it. NAPA sil sealant adheres well to cuben, so … Sometimes you get pleasantly surprised.

Sorry about the way I obsess about these issues before actually making stuff.
It's just the nature of the beast.

Again, nice job on the cuben fly. Wonder how the person you sold it to is faring with it.

[Eric Lundquist]

Dan,

Thanks for your advice on sewing cuben. I've been thinking of purchasing a yard to make some stuff sacks for my gear and was planning on sewing them. Your recommendation of moving to a heavier weight is probably a good idea as I was originally thinking of using 0.51oz.

[Dan @ Durston Gear]

FWIW, this site says you can sew seams after you've used the 3M Tape. You just might need to clean your sewing machine needle with alcohol once in a while.

http://www.sailrite.com/Seamstick-1-2-Super-Basting-Tape-by-3M-60-Yds

[brent driggers]

Hey Dan, Do you know where to get any tape wider than 1/2"?
thanks,
I love those tie outs on your fly. How many layers were the loops themselves?

[Link .]

Same place

http://www.sailrite.com/Seamstick-1-Super-Basting-Tape-by-3M-60-Yds

[John Gelack]

Thanks guys for all your responses, alot of good information here. I decided to get the tape that Joe is selling at ZPacks, this gave me a good excuse to pick up a couple of other things from them. Thanks again, John

[Sam Farrington]

Hmm … Sailrite used to have a bonding or basting tape that did not require stitching – think they called it C-2, or C-3. It was posted on several threads here. Now this one, from 3M, that appears similar to what Zpacks is selling, also from 3M.

Have tested the C-2 or C-3, and as expected, it did not work on silicone treated fabrics, like silnylon or Epic Malibu polyester; however it might work when folding over the edges of cuben to hem it before sewing to other materials. The question for me is how much heavier and stiffer it will be compared to liquid adhesives. Will have to bite the bullet and do some tests to find out. It would certainly be quite a bit easier to work with than the liquids, particularly 2-part Hysol urethane.

My guess is that I will end up with GE silicone glue, because it adheres well to both cuben and silicone treated fabrics, can be applied thinly, is flexible, does not have to be fail-proof when there will be stitches also, seals well, and the clean up is much easier than with urethanes. We'll see.

[Dan @ Durston Gear]

"How many layers were the loops themselves?"

I'm pretty sure I cut a 6" x 2" piece of cuben (might have been 7" x 2"). Then I test folded it four times to form a 6" x 0.5" strip, creating creases where I needed them. Then I unfolded it, covered one side with Hysol adhesive, refolded it and left it pressed under a big pot filled with water overnight.

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