I've just ordered a sheet of tyvek to make my bivy prototypes in preparation to make a sil/momentum or cuben/momentum bivy.

So now I need to decide on which tape to buy.
I'm settled on tape because:
1. I don't have a sewin machine
2. I can use it for both tyvek and cuben (and nylons?
3. It seems relatively simple.

It seems the consensus around here is the 3m 9485 is the best tape for cuben but I can't find it anywhere for retail.

I'm looking at the 3m 9460 or the C3 sailtape from kitebuilder based on recommendations i've heard from people on this site. The question is through, are these two tapes similarly as effective as the 3M 9485? Or should I hold out and find the 9485???

The next question is: will these tapes work on silnylon and momentum? The C3's description says it's for taping nylon sails as well as laminates but I haven't seen anything about taping these fabrics for our application.

Sorry for the repetition I know this question comes up a lot but I promise to post pictures of the whole thing to make it up :)

www.bindingsource.com has 9485PC tape in various widths and quantities for sale, but shipping is expensive.
https://www.bindingsource.com/items.asp?ItemID=1219&Cat1ID=20&Cat1Name=3M%99%20Tapes&Cat2ID=18&Cat2Name=3M%99%20Double%20Coated%20&%20Adhesive%20Transfer%20Tapes&Cat3ID=&Cat3Name=&FamilyID=14&FamilyName=3M%99%20Adhesive%20Transfer%20Tape

I haven't tried it on tyvek, but I think it would certainly hold well enough for a prototype.

For a prototype you might be able to get away with packing tape. I've done that with mylar.

My low level educated mind still has a difficult time grasping the use of tape vs. glueing. In my mind I see the tape failing after a couple years. I assume the glue sort of melts the two pieces together, like glueing PVC pipe together???

For the Tyvek prototype just use PVA. (Elmer's glue)
Franco

> a difficult time grasping the use of tape vs. glueing. In my mind I see the
> tape failing after a couple years.

You're thinking of domestic (or office) sticky tape. The 3M9485 tape is a VERY DIFFERENT THING.

I once tried to separate two bits of PU-coated fabric after they had been taped together with that tape for a few weeks. I got the two bits apart - at the cost of ripping the PU coating off one of the bits of fabric. It's kinda good stuff.

> I assume the glue sort of melts the two pieces together, like glueing PVC pipe together?
That's solvent bonding, and NO, glueing Mylar (Cuban) does NOT work that way.

Cheers

I have no concerns about the 9485 with cuben. It's quite pleasant to use. The strength of the bond is pretty strong as soon as you put the pieces together, and I think of the stuff more as a slightly structured adhesive, rather than tape. There's no carrier/backing like conventional tapes, so it's like putting down a perfectly consistent layer of just adhesive. If you peel the cuben apart, the adhesive randomly sticks to both surfaces, like bubble gum on the bottom of your shoe.

I'm not sure what it'd take for 9485 to fail in the field. I can say that after testing cuben bonds with 9485 to failure, there's not many field scenarios where a properly constructed cuben item is going to have problems at a seam.

Graingers has several widths of transfer tape, but they use their own product number. The generic transfer tape works fine for Cuben:
http://www.grainger.com/Grainger/transfer-tape/tapes/adhesives-sealants-and-tape/ecatalog/N-85e?op=search&sst=All

Do these tapes work on silnylon? Not well. But you can use Pertex silicone windshield sealant (cheaper than 3M and more fluid) as long as you use 1"-wide offset glue lines and then fold the single-layer of the offset over and glue again. Then fold and glue a third time. What you get is like a French seam or lapped and felled seam. Very strong. Play with paper to see how this works. This makes a perfectly reliable and totally water/air-tight seam. Mask the glue line with masking tape and use a plastic squeegee to remove all excess.

Edited by vickrhines on 09/14/2010 10:21:59 MDT.

I appreciate the education in tape vs. glue. I had no idea tape would be so efficient. I really want to try my first cuben tarp soon. I just need to learn which product will work. It sounds like tape and glue are both great options. Again 'thanks'!

Man! That 9485 is expencive even without shipping!

Franco:

Elmers? Really? Will that create a durable enough bond? I have the Tarptent Sublite and patched a tear with the glue Henry supplied and it appeared to be plain old Elmers. It has held up fine but it is in a place with zero stress on the bond.

Thanks for the tip!

Vick
I'll check out that Pertex glue, thanks. It could be perfect for attaching momentum to cuben.

I just found 9485PC at rshughes.com, $28

Help me out with this. Is Lightheart's 'seam taped' the same as what Hyperlight Mountain Gear does?

From HPG's site...."we employ sealed seams which have tested stronger than the fabric itself".