Read the side of the bondo package, it usually says.

Generally you mix a small amount of hardner with enough bondo that you need for the job (too much hardner makes it go off too fast, too little and you are waiting ages for it to harden).

Mix until it a uniform colour (the stuff I use goes pink).

Apply it as you would any filler and wait for it to cure or harden. Once properly hard you can then sand it down, add more where needed or just paint.

Make sure you are using it in a well ventilated area and when sanding use a dust mask. When applying it use gloves (it's a pain to get off your hands)

I've gone through four gallons of Bondo on my project to date. That video summed it up pretty well. The only thing that I would want to stress is, don't mix up too much at once. A golf ball size is probably all you'll have time to work with before it starts to harden up on you. Please post some pictures when you've made some progress. We would all like to see the results.

Yes, a small amount is usually all that you will get through before it starts to harden. It's best to start off with a small amount and see if you can handle more or less each time, you'll find the best amount after a few attempts.

For large holes you will need to use more than just bondo, you will need to bridge the hole with glass fibre matting or you may get away with cardboard, wood or plastic sometimes. Fill the hole in multiple attempts, building it up each time.

Always put slightly more than you need in any hole, but not much more, and then sand to make it all flush and smooth. Don't try to cut corners by either piling it all in there causing much more sanding, or trying to smooth it while filling which will result in a poor finish.

Caution: Sanding it makes a lot of dust.

Your best bet is to practice on a few things to start with. After time you get to know how much bondo you can use in one go, how much hardener is best for you etc. and eventually you'll be a master of filling and smoothing :)

Thank You, very much!

;)

Thank You, very much! sorry for the double post!