Before we put this one to bed, I called the tech line again after seeing on the DPLF tech sheet that it can be applied over a "converter" and seeing Denny's post. I have had very good luck over the years with the same formula, knock all loose rust down, hit it with ospho, then prime and top coat....but this is for mower decks, tractor implements, etc...never an auto body. So natural for me to apply a rust converter after blasting.
In the end, PPG recommends 2 options 1) Option A - blast, clean with DX330, then use DX579 & 520 which are cleaner and conditioner (as Denny says above). This requires a water rinse. Then apply epoxy primer,etc. If I was going for the Ridler, maybe I'd sign up for this.
Option B - blast, clean with DX330, then 2 coats of epoxy primer just as soon as you can, preferably that day, next day at the latest in my humid Houston,Tx climate. On a scale of 1-10, if option A is a 10, Option B is an 8, according to tech line.
Further, in terms of long term preservation, which is my situation, maybe a couple years. (Don't apply K36 Urethane primer yet Deve !). Suggestion is when ready to start body work, scuff the old epoxy primer, apply filler, then another coat of epoxy primer (a sandwich around the filler). Then the K36, then base coat/color and clear if you're doing base/clear. PPG says you only need a sealer after the K36 (urethane primer) if you're painting black. Black pigments, need a sealer for adhesion. Thanks again fellas for good discussion.
