How to use body filler??

[boatbuilder]

I'm planning to eventually bare-metal my bus and respray to achieve a smooth dent-free bus!

In areas like the long side panel where its not rusty, but slightly dented here and there, do you put body filler directly onto bare metal, or do you use an etch primer first and then put filler on top?

 

[rob-stone]

primer-filler-primer-paint

 

[jabbo]

primer-filler-primer-paint

Then primer, filler, primer, filler, primer, filler etc etc. :lol:

Good luck getting it straight Boatbuilder, hope you're a patient man.

 

[boatbuilder]

Ok so let me get this straight....is etch primer the right stuff to use? Something like "UPOL Acid Etch #8" ?

And when I have sanded back the filler after the first application, can I use the etch primer again, on top of the filler and any bare metal spots?

I think I'm definately more patient than the last guy who did repairs to my bus...the filler is reallllly lumpy.

 

[Araon]

You should be able to apply the filler directly to the keyed bare metal, start with a fibre filler to provide the depth. Once thats cured take it down and roughen up blow away the dust / wipe with a dry cloth, apply as many further coats of plastic filler sanding and cleaning in between as required.

Remember that if you apply primers between you risk trapping moisture wich will be carried to the metal surface. Also if you warm the metal your filling you reduce the risk of moisture trapment and speed up the curing process (The hardner cures at min 64 deg F and a gentle heat to the metal will raise that)