Originally posted by Chuck 98 RT/10
Run your hand over the bondo a lot to feel for scratches and imperfections. If you can feel it you will definitely see it after paint.
Prep is everything when it comes to body work. The actual painting is the easy part. Take time and it will pay off.
If you have an air compressor, get a DA and it will save you ALOT of time.
Make sure your bondo is smooth as possible when your applying it. Once your bondo starts to get hard (It will start to feel like your working with clay) Throw it away, and get a new batch, You have about 5-10 minutes to work with bondo depending on how much hardener you use.
If you use bondo thats starting to get hard on you, when your spreading it, you'll get airbubbles and stuff in your bondo, and when you sand it they will show through, and you'll have to apply more bondo.
If you know who's painting it, and your going to be helping, make sure you blow the car off REALLY well before they prime, then use 320 grit sand paper on the primer, blow it off really well again, then clean it off with tack rags, then paint.
The key is take your time, If you try to rush the prep the paint will look like shit. Best advice I can say is do it right, and use a DA.
By the way, what kind of paint are you using on it? Single stage or double stage?