When using either bondo or fiber glass do you apply them to bare clean metal or on top of primered body ok too??

Would it have enough to bite onto with the primer in the way?

The reason i ask is because i want to do it right.

But i also do not want rust forming underneath or i want to know what to do to prevent it.

any suggestions please

 

What part of the car do you need / want to bondo? In my oppinion try to weld as much as you can if possible. Much better then bondoing anything.

 

i agree totally! i guess my question is...when you want to fill in small dents or make sometihng straighter or smoother... using body filler or plastic filler do you apply is over bare metal or over primer..... i'm trying to avoide moisture captured underneath and i want to know how to properly do it

 

I have allways gone to the metal and cleaned "prepped" the surface with acitone or paint prep solvent, keep in mind that was after gettin the offending dammage out as far as possible before using any type of filler.

 

Here is what some of the Rep's have told me that come into the shop

They said that with the old school bondo, you HAD to sand everyything down to steel, in order for the body filler to stick. With all of the new products out, you can actually just sand the finish with 80 grit, and apply the filler directly on it, without having to grind down to steel. If you grind down to steel, you cut through the "E" coat (electrostatic coat) which is a coat to help control rust.


These are just a few things a couple of Reps told me....

 

Ok thanks guys.

Any recommendations for some new and good body filler? I only paln to use a thin layer if at all. I'll find out at my local shop jsut comparing what everyone else uses.

 

I like to use Evercoat : either Rage or Rage Gold on the metal. For the Flexible bumper, etc. I use Evercoat's poly-flex.

I have also used Bondo brand in the past and have had ok results.