How do know if your body filler isnt hard enough? Its not like "play-do" soft but it still has a very slight "tackiness" to it and i can leave a mark with my fingernail. It hasent been sanded yet either. I would think that you shouldnt be able to leave a mark with your nail when its hardened. Did i not use enough hardener?

The filler should get completely depending on the weather it could take up to 30 minutes. If it is taking longer than this you should probably add some more hardener. If you have mixed in enough hardener you can get a way with sanding when it is still 'slightly' tacky. This will allow you to sand it down a little faster but be careful it can be easy to over sand when it is still slightly tacky

This was done yesterday so its had plenty of time to harden but i can still scrape it with my fingernail. I think i didnt add enough hardener. I may have to get all this new bondo off and re-do it:-(

My next question, every time i have done bondo in the past, i was able to see the where the bondo is after painting im guessing because the bondo absorbed a little of the paint. What did i do wrong and how can i fix it.