I have used seam sealer, both with and without sewing the rip. Put a couple of layers of it on and works great. I had a rip in my silnylon tent and covered it with a small patch of nylon and put seam sealer over it on the inside and out, without sewing on the patch. Also has worked great.

lopgok wrote:Duct tape uses rubber based adhesive which fails when it gets hot.
I suppose if it never gets hot you are ok.

Yup. Duct tape is great for taping anything. Except ducts.

I used the Tenacious Tape and Seam Grip and have been very happy. On some tears you can get away with just the Seam Grip but in general it's much easier and neater to use the tape as well.

I have not tried using just the tape, but it seems like it would take a lot of abuse and be removable in case you wanted to get it sewn.