Advice with respect to sewing nylon

you'll have a problem getting anything to adhere to the silnylon unless it's stilnet or some other sort of diluted silicone caulk. That may not really even work in terms of bonding but more in terms of sealing. I don't think you need to replace the torn out section with cordura brand silnylon. There's lots of places to get silnylon for $3-10/yard (diy gear supply, quest outfitters, etc). It is definitely a really frustrating material to sew with. you can try folding edges over and ironing on low heat to make a more defined edge. I think the main thing is just to use tons of pins. that way it can't slip out.
Michael

I would contact OWFINC.COM. (Outdoor Wilderness Fabrics, Inc.) They have some seconds that look really good, especially for patches. Yeah, as far as sewing it goes, as Michael says, pins. Some adhesives work fine, though. But, they make a bit of a mess. Ask when you call in. I seem to remember they had some stuff there.

On small length stitches, I normally feel like pins just get in the way. I've actually had great success using a normal glue stick on silnylon to help keep the pieces from moving around. It won't hold the pieces together well but it will create a non-slip surface between the two pieces.

I have used this method a good deal and haven't seen it mess up my machine. Once the glue dries, it can look odd, but you can just rub it off.

Maybe patches with the same material as the tent would be best. Then, they would stretch together and share the load better.

Just sew it. The stretchiness and slipperyness is more a problem on long seams.

Sew some test pieces first to get the hang of it.

Do you have any pictures of the failure? That would be interesting

Wouldn't cuben seam tape work?

Has to be silicone based to stick.

I have used undiluted silicone caulk spread out as thin as possible with a putty knife to glue peak and tie out reinforcements to my homemade tent. I haven't even bothered sewing the reinforcements after that and I don't think they will come loose anytime soon. It's probably a lot stronger than if I had just sewn on the second layer of silnylon.

Thank you everyone, you're a wealth of information!

1] So b/c I don't have any faith in my sewing skills [yet], I've decided to use some silnet first to bond the reinforcements on first. Once dry, I'll then sew. I already had some 1.5 oz silnylon on hand so that's what I used for the triangular reinforcements. I'll try and get some pictures up. The rip is about 1.5" in length and through the doubled-up hem immediately adjacent to one of the side tie-out points.

2] Any advice on needle and thread size? I was thinking about V30 thread and a #12 needle?

3] Can anyone talk about fabric adhesives [not for silnylon] for heavier packcloth? Any brands or types that need to be used?

McNett Seam Grip works on non-silicone fabric. Or Shoe-Goo is similar.

If you sew through fabric an silicone, your needle may get gummed up, and then your machine may get gummed up so watch for it.

How did your sailrite work on the silnylon?