C3:K36 or K38 PPG

[Steve L.]

Which one is more suitable for a high build primer to fill in rust pits after applying DP90LF?

Thanks
Steve L.
73 since new

[Dick W.]

Re: C3:K36 or K38 PPG

I have always used K 36, blocking it back down to the DP

[Steve L.]

Re: C3:K36 or K38 PPG

The PPG documents don't show much of a difference that I can understand. Do you know what the difference is?

You and others have mentioned to block down to the DP90LF. The PPG document say not to sand the K36 or K38 to less the 2 mils but blocking back down to the DP90LF will probably get this down to that range. I suspect that these high build primers are probably very fragile so you want to get rid of as much as possible...basically to even out the valleys.

Steve L
73 since new.

[Chuck S.]

Re: C3:K36 or K38 PPG

I have just become aware of K38, and I believe K38 is for extra heavy film build. I plan to use K36...it's darn hard enough to spray K36 before it begins to set up in the gun. I finally resorted to mixing K36 in gun cup volumes in order to have good even spray application. I can only imagine how it would be to spray K38.

That's correct...it's does say not to sand below 2 mils, and it adds to be careful not to oversand. If you're going to block it back down to the DP epoxy primer, I believe I would add another couple of coats after the blocking to insure I met their requirements. You'll still have to sand again for good adhesion.

BTW, "evening out the vallies" is blasphemy to the purist.