I've done alot of spray painting myself, and I know that when the first thin coat is laid down, it forms a strong bond with the primer (try removing it once it's dried!). This is why I'm wondering why the paint BB/CC paint on my 69 Chevelle will chip and peel cleanly away from the primer anytime I have disturbed the paint around a screw hole, or where a final sheet metal modification had to done in an area that would not bee seen. This job was done by a professional painter.
Any ideas on this?
Thanks,
Rich

Hey Rich,sorry about your paint,sounds like the painter missed his window,primer/sealer has a window in which once sprayed it needs to be top coated,if you spray the topcoat after the window has closed it does not get a bite into the primer and the topcoat will chip easily off of it.If you spray the primer/sealer and wait to long to topcoat you must scuff/sand the primer so the topcoat gets a tooth/bite into the primer.Primer/sealer usally has a window of 24 to 72 hours depending on what product is used.Also mixing products from different manifactures can cause this.Some people say this isnt true but it is and I have experienced it first hand.Another thing that can make paint chip easy is to much primer/surfacer,the builder in primer /surfacer is talc,I know,its a four letter word.talc is the weak link of any paint job,yes it helps make the substrate look straiter when blocked but chips easy,the more you use the easier your paint chips.hope this helps,Darryl

Thanks for the response Darryl. I thought that PPG K36 Hi-build primer could be on the car for weeks before being topcoated, while the DPLF epoxy had a window of one week. In the places I have seen peeling, it was the color coming away from the K-36. Could you comment on this?
Thanks,
Rich

hey Rich,Yea the k36 can be on the car for along as you want before basecoat.the k36 is what has the talc in it also, and if a paint job is going to chip, it will there.the only other thing i can think of is I wonder what the k36 was final blocked to?How many coats?the more coats of talc,the easier it chips!If it was final sanded past 600 wet or 400 dry it would tend to chip easy there also.The only other thing I can think of is that the car was not washed/grease and waxed well before paint.I always use dawn and warm water with scotch brit and final prep. which is an abrasive and it seems to work really well,not to put down your painter but some are "blow n go" type people,thats how they make more money.You can go to a full on restoration shop and have your car done by guy" a "that works there ,5 years later you need it painted again,but if you would have had guy "b" do it it might last 25 years.both are pros but one has pride in his work!bummer inst it.I guess what Im trying to say is with your problem,I guy would of had to be there to see what step wasnt taking right,Darryl

Yes, alot of variables at work Im sure.
I did try scratching the paint under where the door sill plate will go and found it to be pretty tough. The scratch exposed the primer of course, but it didn't peel or chip around the scratch. Oh well, the main reason I had it done in a non-metallic red, was b/c I knew it would get nicked and scratched eventually, and i can repair that alot more easily than with metallic.
Thanks,
Rich