Posted by Keith in Washington on Wednesday, May 17, 2006 at 1:33PM :
In Reply to: I hate to be the bearer of bad news... posted by chris case on Wednesday, May 17, 2006 at 11:07AM :
Are you sure that that is paint under the pink bondo? It looks like bondo where a different color hardener was used.
Actually I have been told by several sources that you need to use a good 2 part primer (DP40 as an example) under the bondo. The reason why is simple. If you see peeling bondo it is often because rust has gotten between the bare metal and the bondo (often through holes from pulling with a slide hammer). Before long the bondo will pop off. We have all seen this. If you have a good primer under it rust will not get under the bondo as there is no longer bare metal. Shops in this area are priming prior to putting bondo on.
Obviously bondo will crack, peel and pop off if it has been put on too thick. I try to keep it under 1/8" which is about half the max recommended thickness. Using a slide hammer that works with studs that spot weld to the body are great. It is the only way I go. I borrow a frinds tool to do it with.
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