I have some rust holes in my cj-7 that I need to repair, but I dont have a welder. Can I use fiberglass resin to repair the holes, or do I have to take it to a body shop to get the holes welded and then use bondo???
Depends on the size of the holes and how good you want to do the job. You could pop-rivet a piece of metal behind the hole and bondo it up. I did this on a car once and it still looked good the day I sold it about 4 years later. As far as I know it could still be there.
I've have good luck with fiber glass patches ... if your strapped for cash ... the kit is like 15 bucks at wallmart just make sure you get a fiber glass cutter thing (they look like a wood plane) fiber glass is a pain to sand down.