What they said.PPG's DBC is DBC500 and the DBU line is DBU500.Scott uses the better Global line.If you have access to the mixing rack,DBC500 is nothing more than 649 mixing clear mixed with an equal part of 689 binder.For DBU the 649 is universal to both,but you substitute the DBU clear binder for the 689.It's original intent was to clear down color on those hard to blend metallics,but it's also great to make candies with and for the intercoat barrier.PPG says to use it for a jambing clear,but I won't.Just remember this stuff is base.It's thin and you don't want to plow it on to lose an edge.Too much base isn't good,that's why DBU has a hardner in the reducer.They make a hardner for DBC for the thicker custom stuff,but I've seen serious adhesion problems from using it.The clear comes off in sheets.Personally I don't like DBU and have had to use 6 or 7 coats of DBC from earlier transparent formulas on a spot job without any problems.Kind of pushing it IMO but.If you think you're getting thick lay a few coats of topcoat clear down and pick back up where you left off,just don't sandwich the base and clear alot.2 basings and clearings with a reclear is getting thick,but you're playing in the custom area with no guarrantees from the manufacturer.As long as you treat it as a thick custom job (like don't let it bake in the sun everyday) you'll be fine.
