body work

[lm48]

I am done with the mechanical restoration of my 79 and know is the bodywork time. When the paint is stripped down to the metal which one go fist, the bondo (to cover small dents) or the primer. I do have a good quality of epoxy primer for direct metal application. I did one door today where bondo went fist and then primer and I end up with 3 blisters. Before spraying the primer I did wipe the surface with a metal cleaner and this was possible the cause of the blisters. After the primer cured the blisters where gone but I know there is no adhesion there.

[azruss]

bondo is applied to the metal. this is a mechanical bond so the metal should be rough. 30 grit. You can use a metal conditioner but needs to be neutralized. I assume you mean the primer bubbled on top of the bondo and not on the metal. If this is the case then you have a contamination problem with your bondo. Sand to 200 grit, wash with a automotive paint prep degreaser. Use paper towels and apply and wipe off according to instructions. wear latex gloves so you dont contaminate the service with oils from your skin. If you sprayed using an air compressor, the air can be contaminated with oils. Auto paint supply houses have cartridge filters that screw into the air inlet of the paint gun that will clean the air supply. With a chemical hardened primer like epoxy, you should be able to bondo over the top. same rules apply as above.

[dom]

If you are stripping to metal then you need to use an epoxy 2 part primer, regular primer will not work (or you can use self etching primer for metal if you don't want the best). Once all paint and old body filler is removed you should spray the whole body with epoxy and then you can start doing body work. A good quality Body filler (3M) is designed to stick to epoxy, which of course must be scuffed. That is the way the pros do it these days. Than a 2k primer once the body work is done. Doing is this way seals the metal first since bare metal will begin to rust simply from air moisture.

[kmac33]

If you are stripping to metal then you need to use an epoxy 2 part primer, regular primer will not work (or you can use self etching primer for metal if you don't want the best). Once all paint and old body filler is removed you should spray the whole body with epoxy and then you can start doing body work. A good quality Body filler (3M) is designed to stick to epoxy, which of course must be scuffed. That is the way the pros do it these days. Than a 2k primer once the body work is done. Doing is this way seals the metal first since bare metal will begin to rust simply from air moisture.

ditto. Same process used on my resto.

[lm48]

I got the epoxy primer and works great, easy to spray and hard like a rock. For sure I can’t make a leaving painting cars. 9 h on a door with out paint, just prime and bondo is not a record in a good way. Finally got the surface smooth ready for paint