I was wondering if I should use a metal prep wash on my body before the etch primer. I had bad laquer check and I had to strip the factory paint all the way to bare metal. Also will it be ok to etch primer over filler? Does the etch primer require sanding before the surfacer is applied ?

i would not use metal conditioner and etch prime. Just use the etch prime.It is fine to use over filler.Let the etch prime dry an hour or so then put your 2k prime right over it.If the etch prime sits for more than 12 hours i would scuff it before priming over it.

PPG's dx1791 when applied to clean bare metal, the sue of metal treatments is NOT REQUIRED OR ADVISABLE. They both contain acids that etch into the metal but the acids in each product dont like each other. Also if it sits for more then 24hrs it must be scuffed and recoated. The flash time to priming on DX1791 is 10-15mins. So wait 15 mins after spraying the dx and go right to your primer. Yes etch can be applied over filler but dont apply bondo over the etch. The chemicals in the bondo's hardner can lift the etch, due to acids that dont like each other.

This holds true with all the etch's out there not just PPG, dupont's variprime is the same and so is S-W's etch. I would sand all bare metal area with atleast 180 grit or 220...Eric