The steps in this thread are intended to demonstrate as simple and straight forward as possible the process of mixing , applying and leveling autobody fillers and putties. These are the steps to take after metalwork has been completed.

Click on pictures for a closer look, what can be helpful for those working with bondo or putties for the first time is seeing pictures of amounts of product used before when mixing ratios are important. A picture can be as good as a couple hundred words but the best will always be to get in there and get some practice. It may seem overkill to those who have done it before but it's the little things that matter early in the process.


So with hopes of showing a overall visual to the newcomer in the hobby,,,

Step-1 #36 grit to remove paint. Use a slow speed on your tool to avoid heat build up. Heat can warp metal out of shape fast and create more problems.

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Step-2 #80 grit to remove the 36 scratches. Blow the dust off with compressed air so the filler will get a clean grip.

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Step-3 Mix filler , In the picture is a gallon can of Rage Bondo , a tube of Iceing putty , some 'Plastic Honey'(to thin bondo) and a tube of hardener. It also shows the ratio of hardner to filler for a average mix on a warm day. I know what it says on the can and in the books but here's what it looks like in a picture.

*Edit**-> 2007 Here's a great link that puts it in text.
.http://www.roadsters.com/filler/

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Step-4 , mix hardner and filler completly useing the contrasting colors as a guide.

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Step-5 , When it's one color you got it,. It's also time to focus on the next step cause in about 3 minutes it will begin setting up.

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Step-6 , Spread filler over the complete area every time .. Press hard on the spreader the first couple passes. Then kinda glide the spreader to allow filler to build up.

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Step-7 , By the time you've cleaned your spreader the filler is about ready to be worked (3-4 minutes,longer time will be needed in lowwer temps.) Useing #36 grit sand lightly (just grace the panel) so not to clog up the paper with the barely set up filler. It should shave easy as cheese yet not be wet so it loads up on the sandpaper. Waiting to long will make this 5 minute task a very frustrating 30 minute one.

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Step-8 , Sand the entire area down at the same time . If metal starts to show inside the repair area you know you have some high spots from over pulling during metalwork.

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A few LIGHT TAPS will knock them down below level

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Repeat steps 3 through 8 if there are high or low spots and HERE ARE THE 3 SECRETS to getting the filler to sand EVEN and LEVEL.

#1 Always use a sanding board or backup block with fresh paper.

#2 Always use crossing , xing strokes to achive contours and straight back & forth strokes to flatten covering the entire area with thought out strokes,,remember it's important where you stop and change direction of a sand stroke. A low spot will develope where the sand paper cuts in twice as much where it stops/starts & changes direction so be knowing it.

#3! When applying additional coats of filler , SPREAD/COVER/COAT THE COMPLETE AREA each time. **The reason behind this is each batch of filler you mix will have a different ratio of hardner to filler. Not by much but enough that there will be some change in the rate it cures and thus the rate it will sand. If you only cover half the prior coat of filler or try to 'spot' fill let's say, that batch will have more or less hardner in it and will sand at a different rate/speed than the other and you'll chase it all day. In order to have consistancy you must spread each additional coat over the whole area ,it's that simple.

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