Welcoming any thoughts/tips for bonding cuben to make a air and water tight seal. Tape ?

Many thanks !

Not sure about air tight like for a mattress, but you can glue it with aquaseal Urethane repair adhesive and sealant.

Other companies make the same glue. I think Locktight for one, but not 100% on that.

Really sticky stuff waterproof and pretty nasty.

Will glue anything to anything, IE cuben to cuben, cuben to sil, or sil to sil, or to regular nylon, or to tyvek etc.

The material will fail before the glued joint on those materials.

Only thing I found that it would peel away from so far was Polycro but it took some force.

There was a guy here about a year or so ago that built a square Cuben tepee sort of shelter that glued the entire thing. If I remember right he diluted it with a thinner and brushed it on.

Edited by tammons on 12/14/2010 20:35:08 MST.

There's a lot of good info contained in these threads:

http://www.backpackinglight.com/cgi-bin/backpackinglight/forums/thread_display.html?forum_thread_id=20093

http://www.backpackinglight.com/cgi-bin/backpackinglight/xdpy/forum_thread/37663/index.html

If I had to boil this down to a few tips it would be:

1) Tape where you can. It's much faster, easier and less messy than glue.

2) The 3M & C3 tapes found here work well.

3) Design all seams in sheer, not peel (good discussion of this in 2nd link above)

4) For reinforcement patches and similar work, glue may be easier than laying a lot of tape.

5) Grommets work great for the tie outs etc.

6) 1" tape is good for major seams, 1/2" works well for finished edges and less stressed seams.

7) CT2K.08 (0.74oz) is bomber for tarps etc. CT1K.08 (0.51oz) works well with a good design and a bit more care/responsibility. The even lighter variants are a fairly radical fabric that requires flaw-free design and careful use. For floors, groundsheets etc you want to use heavier cuben like CT3.5K.18 (1.26oz) and CT5K.18 (1.5oz).

8) The product codes of cuben work like this: CT = Cubic Tech, 2K (the amount of spectra), .08 or .18 (thickness of mylar layers on either side).

Edited by dandydan on 12/14/2010 21:07:28 MST.

Dan, that summary was the best post on cuben I've read yet.

You can make airtight seams using tape or adhesive but at the end of the day the material itself is not airtight.

As Dan said tape works the best for simple lap seams.

How do you put a zipper in a Cuben tarp?

Reinforce and then sew.

At a minimum, fold the edges of the cuben and bond them (ie. hem the edge) to make the cuben 2x thickness and then sew the zipper into that.

Thanks for zipper suggestion

That's just what I was thinking

Would you use a #5 or #3 zipper for a tarp?

It mentions above that there is a glue for bonding sinylon??

Can somebody post a link if so?

It's seems to say it wil be stronger than the material itself. So can I make a multi piece tarp without using a sewing machice and still end up with a super strong end product?

http://www.backpackinglight.com/cgi-bin/backpackinglight/myog-laminating-silicone-impregnated-fabrics.html


Above is a BPL article on silnylon laminating and it talks about glue.

> Would you use a #5 or #3 zipper for a tarp?

I use a good #3 zip on both my summer AND my winter tents. Lasted for many years with no sign of problems - but we do take care of them.

For novices and small Boy Scouts ... #8 maybe? :-)

Cheers

Thanks

I've always used #5, but now I'm beginning to rethink.

The only problem is the local fabric store doesn't have #3 so I'll have to do mail order.

If you think there's going to be a fair bit of stress on the zipper then I would go #5...especially if it's fairly short zipper where the weight difference will be tiny. For most applications though a #3 will be fine. Use a waterproof (ie. uretek) zip rather than a regular zipper because it saves a lot of hassle/weight trying to make a storm flap over the zip.

Troy,
Interesting comment. Have been looking for something to seal a seam that is Epic or Sil joined to Cuben or Nylon with PU or DWR coat. Can use a more specialized sealant over the stitch lines, but also wanted to seal where one material meets the other. Sounds from your post that the Aquaseal Urethane Repair Adhesive and Sealant might do a decent job, maybe diluted. Will experiment. Thank you.

Did not want to leave my last post on this thead alone, given the results of the following:

Tried the McNett urethane sealant and found that it would not securely bond the back of a velcro pile square to the PU coated side of a scrap of 4 oz. Spectra Gridstop (peeled off fairly easily)(let it cure in a warm place). Then tried Elmer's ProBond urethane glue, and could not pull the velcro off. Have had good success with the Elmer's repairing the soles of Keen mids, and glueing velcro pile patches in them to improve fit.

Tried both the above sealants with silnylon strips on the Gridstop, and they both peeled off easily. Got me to wondering about how to seal the edge of a silnylon pole sleeve (chosen for strength and elasticity) with a Cuben canopy; so tried Permatex autoglass sealant on the Cuben, and voila', it worked even better than seamgrip, and being a silicone adhesive, adheres well to silnylon.

So tried bonding a strip of silnylon to 2K Cuben with the Permatex. It adhered well enough to pull (with only moderate effort) the mylar coat off the Cuben, exposing the fiber threads.

The posts on this site about the effectiveness of bonding Cuben with Hysol are very convincing, but does the Hysol penetrate into the Cuben threads to keep the mylar from delaminating as above under stress? If not, then stitching may be required for secure seams, with the bonding material being used to both reinforce and seal the seams.

At least I've found a good way to seal silnylon to Cuben seams, but am now concerned about just how rugged the Cuben really is. An even greater concern is about how well the mylar covering will hold up to repeated creasing of the Cuben material from folding and stuffing over time. As of now, I plan to go ahead and use it for the front half of a tent canopy, so time may tell.

Hi Samuel,

Do you have any photos (or could you take any)of the delamination of the cuben at the permatex bond? Did you pull toward an edge, and find that the mylar tore first and then delaminated toward the edge? Or did you pull away from the edge?

Samuel, good going with those glue tests, what colour is that permatex? Sounds a lot easier to buy than the Hysol, my last tube from Mcmaster Carr was a bit old , maybe shopworn ,not in a proper bag. As for durability, I noticed to that repeated folding does make it look poor but I have yet too make it leak by that means [ delamination does not seem to be in the cards]. As for glue getting past the mylar , I doubt it, sewing would help but then you would need to glue another strip over to seal.
As for tape, the basting one from sailrite it has its uses in non stressed areas , the C3 must require a rock solid technique to use. It all depends how much stress are you really going to put on it?

I find that the limit of glue [and cuben]is delamination, a fact that gives credibility to tape enthusiasts.

As to the original question here, water tight bonds, are quite easy with straight flat ones, glue or tape, but no wrinkles allowed![ easier said than done], but i have found that with complex curves that are not a perfect fit i have had to add addition layers to get a seal.