is cuben hard to sew

Jay,

In my experience cuben is easy to sew and much less slippery than silnylon.
The main problem is in cutting the stuff. I finally found that pushing a pair of half open scissors through the fabric works pretty well. I would also advise getting some cheap fabric to prototype what ever you are going to make before you go chopping up the expensive cuben.

Happy Trails
-Mark

Just remember that when you sew it, you are creating a row of leaky holes which will get bigger under tension. Seam sealing with tape is highly recommended.

Cheers

I agree with Roger. Sewing the cuben produces a line of perforations that can tear (it hasn't actually happened to me, though). Cubic Tech recommends adhesives for seaming. I've used both the standard and the low viscosity two-part urethanes that they recommended. It takes longer than sewing and it can be a little messy but you get a seam that's very light (flat and almost invisible), much stronger, and waterproof.

I've never used the adhesive, just seam sealed my stitches. Never had a problem with leakage or tearing. I believe Bill Fornshell of this forum uses a sewing machine on his extensive DIY cuben gear. However I can see where adhesive may be a good alternative. How are the cuben tarps that BPL offers seamed? Anyone know?

-Mark

Sewing doesn't decrease the tear strength to any real degree
as the needle holes puncture the polyester film but not
much of the scrim in the middle. Tape alone may in fact
be weaker as it doesn't connect directly to the scrim.

What Roger is saying is that the needle holes can enlarge under
tension, which may in turn cause leakage. Sealing the seams
will help prevent this. Seam grip or Aquaseal work well.

Can Cuben be cut with a hot knife?

"Can Cuben be cut with a hot knife?"

I just use an X-Acto knife with a new blade in it. Cuts Cuben great.

Kepp us posted on your cuben plans Jay.
I'm keen to see how the cuben procurement and MYOG goes for a fellow NSW member.

My winter tent that is calling for a new cuben fly.