I would like to get some info on glue for silnylon. I do not know how to sew but would like to make a bivy. I haveheard of others glueing seams can or should this be done?

you could use GE 100% silicone sealant. I have used it to glue lifter patches on a tarp-tent.

However, it will be a lot heavier than just sewing it and if you are joining silcoated and uncoated it may not stick well to the uncoated fabric.

If you can make a pattern and cut it out you can easily sew it together vs. gluing. I think you would be much happier with something sewn vs. glued.

-Tim