Thread: Body Work

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I will hopefully be doing some body work on the car by the end of the weekend and was told that I needed to spray the bare metal with some kind of epoxy which I had never been told before. So my question is can I put bondo on bare metal or do I need to put something on it first? Thanks for your help.

Two schools on that, pastor.... Some, me included, prefer to do all the filler work before spraying on the epoxy primer, others prefer doing the filler afterwards.... Not sure who's right but with the surface properly cleaned and roughed so that the filler will get good mechanical and chemical adhesion both seem to work fine. The one thing I've learned is when picking fillers, pay more attention to the quality of the product then the price. I use Evercoat products, good quality and not too bad a price but other brands are at least equal, I'm sure......

The pro body guys will be around with some input, I'm sure.....

The two schools of thought are probably both correct depending on the size of the job.

Seems to me that you would be OK to do the body work and then seal the work with epoxy primer when doing just "a spot repair". But when doing a large area like a blasted body or frame, I think you would be better off sealing the whole area first then doing the body work on top of the epoxy sealer. Reseal the repaired area.

My question is what experience has anyone had with doing body work and final paint "on top" of powdercoat primer?

epoxy it first dude, the "grind paint off before applying bog" thing is an old school technique for the following reason. people put bog over bare steel because back in the old days before 2 pack paint systems were the norm when lacquer and enamel was used if you bogged over it and sanded through the paint around the repair when sanding the filler or feather edging for primer the thinner in the primer and subsequent layers of paint would attack the paint edge and youd get a nice fried up ring around the repair when it got painted. nowa days with 2 pack paint systems this isnt nessessary depending on the size of the repair you just key up the paint already there-and if the paints sound there aint much point in removing it-and some manufacturers recommend this or priming steel first over bogging over steel because the modern bogs stick better over primer than over bare steel and they dont chemically adhere the the steel . also when a panel beater grinds the paint off after getting the dent out the air has already started getting at it and then he feels the panel up on the bare steel with his bare hand (ive seen some wear gloves but not all) putting moisture on it youre already being set up for a failure. then when they put bog over the steel its sitting around soaking up moisture down to the steel untill the painter gets it to prime it and seal it off. if you have a car that has bog thats starting to lift i guarantee itll be bare steel and rust under it and youd be able to lift the rest off easy with a putty knife or screw driver under it. in the body shop doing collision repairs there isnt always time to prime it first though with insurance companies constantly putting the squeeze on times and customers demanding their cars back though and it would make it more expensive for them and joe bloggs generally want it done cheap and by the time it shows through theyve sold their beater and have a new car anyways. you cant have the customers car sitting around for a week takin all these steps. on a hotrod or something you plan to keep for a while i definately would prime it first. two medium wet coats-which is how epoxy primers are applied not like acid etch primers- of ppgs dp-40 epoxy etc (you dont want an acid etch primer) then a coat of primer surfacer you can key for the bog because dp40 is a non sand surfacer. you definately wouldnt need to grind the paint off on repairs if your car is done in two pack. if its done in acrylic lacquer or whatever definately get it off and dp40 it first

if youre doin a small area you should be sweet though but on the side of a vehicle say, epoxy the sucker first

hey john up there IMO i think youd be better off using an automotive primer part of the system your using for paint. i reckon powder priming would be too hard, automotive primers are slightly porous so the paint sinks into the pores somewhat helping them adhere (why they recomend you paint over them within the week usually because they close up as it hardens) and i dont reckon this would happen with the powder stuff itd be too hard and they are sprayed electrostatically so i dont think theyd be so easy to key for the paint to stick. incredibly hardy for suspension and undercarriage though but they dont need as much prep as the body to make it straight etc so you can get away with it down there

Originally Posted by chopped66impala

epoxy it first dude, the "grind paint off before applying bog" thing is an old school technique for the following reason. people put bog over bare steel because back in the old days before 2 pack paint systems were the norm when lacquer and enamel was used if you bogged over it and sanded through the paint around the repair when sanding the filler or feather edging for primer the thinner in the primer and subsequent layers of paint would attack the paint edge and youd get a nice fried up ring around the repair when it got painted. nowa days with 2 pack paint systems this isnt nessessary depending on the size of the repair you just key up the paint already there-and if the paints sound there aint much point in removing it-and some manufacturers recommend this or priming steel first over bogging over steel because the modern bogs stick better over primer than over bare steel and they dont chemically adhere the the steel . also when a panel beater grinds the paint off after getting the dent out the air has already started getting at it and then he feels the panel up on the bare steel with his bare hand (ive seen some wear gloves but not all) putting moisture on it youre already being set up for a failure. then when they put bog over the steel its sitting around soaking up moisture down to the steel untill the painter gets it to prime it and seal it off. if you have a car that has bog thats starting to lift i guarantee itll be bare steel and rust under it and youd be able to lift the rest off easy with a putty knife or screw driver under it. in the body shop doing collision repairs there isnt always time to prime it first though with insurance companies constantly putting the squeeze on times and customers demanding their cars back though and it would make it more expensive for them and joe bloggs generally want it done cheap and by the time it shows through theyve sold their beater and have a new car anyways. you cant have the customers car sitting around for a week takin all these steps. on a hotrod or something you plan to keep for a while i definately would prime it first. two medium wet coats-which is how epoxy primers are applied not like acid etch primers- of ppgs dp-40 epoxy etc (you dont want an acid etch primer) then a coat of primer surfacer you can key for the bog because dp40 is a non sand surfacer. you definately wouldnt need to grind the paint off on repairs if your car is done in two pack. if its done in acrylic lacquer or whatever definately get it off and dp40 it first

All good points Impala.....are you trying to say that my (extended) age is showing??????

Oh well, I was welcomed to the geezer club long ago!!!!!!

hahahahaha yea im only 24, been painting for 8 years and learned on ppgs deltron system strait into 2 pack so fresh point of view even though experience is still lacking a bit in comparison haha. bet i could learn a thing or two from you dave haha

Originally Posted by chopped66impala

hahahahaha bet you could show me a thing or two though still haha

Naawww.... I'm not any kind of pro body guy at all, which is why I usually end my comments on body questions with "wait till the pro's come around." I'm primarily a chassis builder and self taught tin bender..... body work became a necessity when I couldn't afford the kind of work I wanted done on my stuff!!!!!! Did the body shop deal long enough to learn it, but not so long that I got burned out on it..... Mostly now I just do my own, and for a few friends....

if you use ppg dp i will bet you ...you will see a ring round your repair for over 27 year s i slung a alot of hash at many greasy spoons

...havent yet pat...

Originally Posted by chopped66impala

...havent yet pat...

well how along have you been at the game

Originally Posted by Dave Severson

Naawww.... I'm not any kind of pro body guy at all, which is why I usually end my comments on body questions with "wait till the pro's come around." I'm primarily a chassis builder and self taught tin bender..... body work became a necessity when I couldn't afford the kind of work I wanted done on my stuff!!!!!! Did the body shop deal long enough to learn it, but not so long that I got burned out on it..... Mostly now I just do my own, and for a few friends....

yea man i got into it so i could do it all cheap myself, its one of the more expensive aspects of doin up a car. im gettin burned out already tho

Originally Posted by pat mccarthy

well how along have you been at the game

hahaha yea not as long as you man but long enough mate, long enough almost too long already

Originally Posted by chopped66impala

hahaha yea not as long as you man but long enough mate, long enough

well we get cold round here and if you try to push a job out like we had to do like bump paint the same day you could not do it and not see the job back with a ring.... the shop not being warm when it was below 20 out side your repair with the dp the thinners would dive down and pull up