Like I have on the web site, you can use Z-Pozy Finishing Resin
http://www.zapglue.com/. I have heard of others using West Systems resin also but I have only used Z-Poxy. The reason I thin it is to cut back on the amount of resin used so it will add very little weight. Remember you are not looking to add strength but a perfect surface to paint.
If you lay the cloth down and use the brush to make static you won't get hardly any fraying. I'm not sure I would dip the cloth in the resin first....seems like a lot of waste when it's expensive stuff.
I've never heard of bondo resin, is it some sort of polyester resin....does it stink??
Let us know if you have more questions.
Remember, keep it light!