[Beenaway2long]

To settle a brotherly battle, I need 2 answers from those that KNOW PPG products inside and out.

Vehicle: 73 Z-28 w/ Goodmark Quarters, OEM balance of car. Taking car to bare metal to get rid of 2 previous paint jobs.

Problem #1:
Goodmark quarters- Can they be immediately topcoated with DF50LF w/401 or do they need to have the "E-coat" sanded off. PPG "P" sheet says its ok as long as the ecoat is not truley a thermo platic coat. IS goodmark true Ecoat or Thermoplastic coat? (My brother already shot them, prior to hanging them on the car. Local PPG Paint distributer made no mention of it to him)

Problem #2
Again, we're dealing with a PPG "preferred distributer"...and I DO NOT know the conversations that transpired, so , that being said... My brother was told he could use the DP50LF as a highbuild primer as well.

This doesn't sound right to me, as it will be a S.O.B. to block out.

Using the PPG line, it is MY understanding that we should proceed as follows:
(After verification of Ecoat situation-possibly sand rear quarters and reshoot DP50LF)

1.) Scuff up existing DP50LF with 320, especially surrounding welds from quarterpanels. Level any runs or roughness from original coat. Sand existing paint off (2 previous colors)
2.) Reshoot whole car with DP50LF
3.) Apply any Bondo as required, and level
4.) Shoot high build primer such as DZ3 Kondar. (or K-38? If K-38 is sanded too thin, lifting may occur-as stated in "P" sheet)
5.) Block out, reshoot DZ3 /block till level
6.) Shoot jambs and under hood/trunk with final color/clear (bc/cc)
7.) Main Color coat with doors/trunk/hood installed (no booth)

He was told to use the DP50LF again for step 4/5. Are they trying to torture him (and me) or did something get lost in translation?

Thanks guys-

[theHIGHLANDER]

The DP epoxys offer good corrosion resistance...that's it. Definately DO NOT use as a surfacer. You're right, it totally sucks for blocking. The old non-LF line was also a decent sealer, but no longer now that it's lead free. Too much shrinkage, especially over bodywork.

To keep it simple just red pad anything you want to do any further applications over. As far as primers, we routinely use K-36. Our rep wants us to try K-38. I feel that the very LEAST possible mat'l used the better the outcome. I never have been a big fan of any high build primers...seems like a crutch for pisspoor blocking of fillers or poor metal work. In rough areas to work over like firewalls, inners, etc, a nice smooth coat of DP anything works well as a non-sanding adhesion promoter. It has a 3-5 day window of re-coat w/out sanding.

Kondar is very "old school" primer. It holds moisture, has poor adhesion, and I've more than once had it show me actual rust after wet blocking. This was weeks after the final finish was applied. The DZ's were too much of a good thing. Acrylic fortified nitro based primer. Keep the work good and smooth, block very well, use the least amount of primers/sealers possible. The only reason to seal is to prevent exessive solvent penetration on heavy primers/fillers. A good sealer is the same base being used, I.E. if you are using a red you cold effectively "seal" with a white base, allow to dry, block it out with say 5-600 wet then go to your final coat. I hope this was helpful.