Spinntex

I don't have any testing figures, but it's pretty strong if compared to regular Silnylon.

Reg 1.35 Silnylon is generally spec'ed at about 14- 16 lbs. Based on this, Spinntex.97 would be within a few lbs.

Just holding it in your hand with an clean cut edge and pulling, it's quite tough to start it tearing. I'm a pretty strong guy and I have to do a full on projectile sweat grunt to get it to tear.

If you make a slit and then start pulling it's some what easier, but pretty close to silnylon.

For a real world reference, only once have I ever heard from a customer about a Spinntex tarp tear. It was years ago and was a tarp with out a tie out reinforcement in 60mph wind.

How you go about sewing and reinforcing it makes a huge difference. even the specifics of what needle size, the stitches per inch, reinforcement size and bias orientation and the thread size/type are important.

Ron, could you elaborate on all the different spinnaker strength variables you listed in the last part of your response? I'm interested in making spinnaker tarps but dont have the specifics of construction down.

Thanks,

Jon

80 needle
40 tex thread (thru-hiker.com)
Stitch spacing definately no closer than a reg #2 pencil lead width.

I think Jay has some more info in his DYI articles here on BPL.

If you want to test it yourself, notch a slit in a small rectangle of fabric, hang the fabric from one of the "tongues" thus created and hang a 5 gallon water jug from the other tongue. Fill the jug until the fabric tears along the slit. Then weigh the jug. That is what the industry calls "tongue tear strength." Another test is to snag a big fish hook such as a shark hook in a rectangle of fabric and hang the jug from that. That's the "grab test" and it will usually give a higher weight. In either test, do it in each "direction" of the fabric – the length of the the bolt and across the bolt (from selvage to selvage.)Many fabrics tear easier across the weft (selvage to selvage) and have stronger yarns running lengthwise. Lightweight ripstops usually (but not always) have symetrical strength.