Sealing a repair in a dry suit

Does anybody know a good product that will re-seal a dry suit after a repair was done to the knee area? It's a brand new suit and was damaged on it's first use in training when the wearer scraped a rock in the water. It ripped the rash guard away from the suit but the suit itself wasn't torn (or the rash guard for theat matter). The stitching ripped loose at the top of the guard and got bigger throughout the day. It ended up being about 2-1/2" inches across. I restitched the seam with some super strong nylon thread and it looks factory fresh again, but I'd like to seal the inside stitches with something to keep it dry in there. I thought about seam sealer that's made for tents but I wanted to check with you guys before putting anything on there. It may not leak at all right now but I think it should be sealed.