HELP: PRIMER over BodyFiller "Bondo"? What to do? Do or Not?

kevin

Ok so Im about to finish sanding the bondo I applied over my truck toyota '85...































Im not going to PAINT ALL the car...just the parts where the bondo repair is...































I know I need to apply primer...BEFORE applying the final paint...































I there ANY DIFFERENCE in using the $5 primer (all purpose...) they sell at the hardware store rather than using the automotive primer?































Will the hardware "all purpose primer" when painting metal surfaces.... adhere well to my bondo all sanded up? Im asking since I have a spraycan on my garage...Its 90% brand-new...































Does the paint used to paint metal surfaces (ex: bikes, rims, poles, etc) be any good AFTER I applied the primer? Will it stick well after 3-4 coats?































So...































Using normal hardware metal surface primer over bondo? Yes...Fair...or NO?































Can I use normal metal paint over the primer?































Ive heard there is an "automotive primer", but I dont know if that is expensive..































Im planning to use "enamel" paint for the final painting job...the one used to paint over metal surfces...































THANKS!!!!!!!!!!!!































note: new to working with bondo body filler....and the car is a 1985 truck...not really interested in leaving the paint as brand new...just enough so that the repairs wotn notice....the old paint with the new one...

Thomas E

You probably want to primer both the metal and the bondo if nothing more than to smooth some of the sanding marks. You do have to primer any bare metal around the bondo edges (there must be some?). Unless you paint entire panels - your repairs are going to be "noticed". There will be a fuzzy blend area where the new paint meets the old paint. If that doesnt matter - then ok. Primer is just a VERY sticky paint that is in fact slightly porous. The top coat penetrates into the porosity which makes it stick. You may have seen primered cars driving around witrhout paint. They will soon have rust freckels popping out through the porosity in the primer. You must paint right after priming (whatever it says on the can) for best adhesion.