Adhesive for sil nylon patch?

For silnylon, the Silnet or any silicone adhesive should work. A possible reason for this failure is, if you glued your patch on the inner side of the tent fly, that it is not silicone coated on both sides but the inner is PU coated. This is common in tents because such fabrics can be taped easily. In that case, PU-based glue should be used, but it won't stick to the silnylon patch and you would need a regular coated nylon for the patch (if the holes are small, you can probably use also uncoated material saturated with the glue)

It is possible that the underside of your silnylon is PU coated but the top (outside) surface is not.
So if you put a patch on the outside smear a very thin layer of Silnet onto the fly, do the same onto the patch, let it rest for about 10 minutes (more if really dry weather, less if humid) then press together and put a weight on it. Wait for 8 hours or more before removing the weight.

> then press together and put a weight on it. Wait for 8 hours or more before removing the weight.
And leave for 72 hours before you do anything with it. Seriously.

Cheers

Thank you for the ideas/input.

Both the tent fabric and the patch fabric have one side that is 'matte' and one side that is 'shiny' … I assume the shiny side is PU coated. When I first attempted to patch I put the Silnet on the PU side of the patch and then applied to the matte side [front] of the tent fabric. I then clamped-it between to square pieces of ply for 24 hrs. The patch peeled easily. As mentioned above, I then tested gluing PU side to PU side with Seam Grip and then clamped for 24 hrs – peeled even easier.

So, from distilling your ideas, I would need to either:

1] use just normal, uncoated nylon and Seam Grip – then clamp/press.

2] use the [potentially PU coated] silnylon I have, but smear a thin coat of Silnet on both surfaces, wait 10 and adhere – then press/clamp for 72 hrs.

Are there any adhesives that would work without question – like Hysol U-09FL? It's used with cuben all the time, what about silnylon.

Thank you!

A company called Gear Aid makes silnylon specific tape:

http://www.rei.com/product/783049/gear-aid-sil-fix-repair-kit

> I assume the shiny side is PU coated.
Doubtful. In general I find PU to be matte and silicone to be shiny.
Try again, the other way around?

Cheers