BC

I repainted my 78 last year (well, during the year before really).

I used all PPG products, and not the low-cost series. I used all the good stuff, and it was in no way cheap.

The bondo and small amounts of fiberglass were applied OVER the DPLF that I sprayed in large quantities over the metal-prepped aluminum or Steel.

Over the DPLF I put the sanding primer. Its a light grey but I forgot its number.

Over that I had a shop spray the color and clear. Three coats of clear were put on.


So, fast forward a year of sitting in the sun, or in the garage, under a car cover or bring aired out.

It chips like its egg shell. If something is metal, it has no chance against it. Entire 1/16 inch chips come off the silver paint and leave the primer underneath bare.

So does this mean it is too fragile? Is it too flexible?

This was supposed to be my daily driver, (its still a shell), but if its this weak, I will stock with the harder, original silver paint on my 86 and drive that daily in good health and give al the good parts to that car and turn the sunroofless 78 into a track car since its all ready stripped.

Its just weird. That paint job is 9months of work on my part and 1000s of dollars, and its very disappointing how weak the paint turned out. It not nearly as tough as the 86's 20 year old paint.

It reminds me of the paint on new Hondas. Flexible but very easy to chip. Too easy.

perrys4

PM Gosane...He will give you the low down.

Tony

I dunno, you can use all the best products in the world but paiting is still a fine art and very much a science in prep and paint usage.

Imo000

Probably too much hardener was used. Did you spray the car or someone else?

wrecktech

It sounds like the primer was not compatible with the basecoat. I used to spray alot of ppg, deltron if I remember correctly and had some adhesion problems. I only spray diamont now and have not had any problems.

BC

I did every last thing before the color and clear. I paid a chop 1800 dollars here in SoCal just to prep that surface and color and clear the car as a whole. It hasn't even been assembled and there are already 5 or 6 scratches and chops from...things that happened outside of my control. When a normal paint job has these issues, the result is dents or small marks. On this paint it just comes off.

BC

The sanding primer was the newer version that is for higher build. It sat for a while, but then it was again 600'ed I think when they did the base coat. Base Coat was also PPG.

perrys4

Could there be a timing issue between primer and color coat? Maybe they are suppose to be done within a time frame?

wrecktech

600 might have been too fine to give the primer a good bite. Is it seperating at where the basecoat meets the primer or where the first and second primer meet?

fst951

Hi Brendan.

We use glasurit and like it the best. One question that I have. The primer that you used...what is it? It is an acid etching primer, epoxy or a high build urethane? If the paint actually soft or just has poor adhesion?

JHowell37

My question is, how thick is the paint? Contrary to popular belief, paint that is too thick is highly prone to scratches and chips. Using too much hardener will not make the paint brittle. The only thing excessive hardener might do is cause the paint to kick early, before the solvents in the reducer have time to flash off. 600 grit is a typical grit to use on high-build prior to going to a sealer or top-coat.

You said you sprayed PPG DPLF (this is epoxy folks) in "large quantities" over the vehicle. Could you define large quantities? More then 1 gallon? How much of the old paint did you remove? How much surfacer (hi-build) did you apply? Did you use a sealer?(this one is not necessary because the debate to use a sealer or not, will be argued until the end of time.) Why did they spray on three coats of clear? Chances are, 2 are what is required. People always talk about all of this extra clear coat their custom paint jobs have. I don't know if that's some BS the shop tells people as a selling point, and treating clearcoat like it's some sort of liquid gold that exponentially increases the value, durability, and appearance of a paint job. Or if it's something the shops are actually doing.

Your problem sounds to me like an issue of excessive paint thickness. Paint that's too thick can lead to the problems your are describing.

Oscar M

I did my 911 not too long ago and started by going down to the metal. I acid etched the metal and followed by etching primer. Next was the body work, primer, guide coat and more primer. The color went on the same day as the clear coats...3 of each. The timing between coats is critical in order to avoid solvent popping...no problems here. After about 2 weeks I sanded and buffed. There's several things that may have happened to cause a poor adheasion of the color and primer, compatibility of products, hardener mix, etc...... Flex agent is used in areas like flexible bumpers or other areas but it doesn't sound like this is the problem. The grit of sandpaper used just prior to color may have also played a role...too fine a grit will not allow proper bond. If youtake a short drive to Lake Elsinore I can have a closer look. I'd like to have CG, a good friend of mine who knows much more about these things than I do take a look as well.

-Oscar

BC

When the paint chips, I see mostly the light grey sanding primer.

I don't want people to think the paint is peeling off, but I am concerned about the ability of small forces to chip or scratch the paint so easily.

BC

It was PPGs DPLF.

So it was from the base metal (aluminum was down to clear aluminum, and the steel was at the galvinazation)

Metal Etch (different kinds for AL and Steel - AL gets the alodine-like stuff, and the steel gets the more acidic stuff (or is it a base?)
DPLF
K38 High Build Primer surfacer
Color (DBC 2000 I Think)
Clear

To answer the last quesion, it seems soft to me. It doesn't have the same "fingernail" hardness that the 86 right next to it in the garage has.

Lets say a hypothetical tool was dropped straight onto the rear hatch by a very sorry hypothetical wife. Not a sharp tool, but a heavy one. The paint chipped at each contact point of the tool, where it would have just logically dented a more professional paint job.

BC

The clear was applied in three coats they said. I was not there for the color and clear. But I did everything up until then.
...The DPLF was put on in probably two separate coats. total. Always sanded and preped before the next application. As I mentioned, the bondo and fiberglass was put over the DPLF by advice I "Read on the 'innernet' " It was said to improve rust resistance.

Every single spec of original paint was removed before the metal prep was applied as a prep for the DPLF.

The paint is not chipping past the sanding primer.

The K38 was put on over the DPLF. Alot of K38 was used and blocked for basically weeks by me. This was a 1978, and while in very good shape over all, the blocking coat really showed me some sections that needed straightening, and the highbuild accomplished this for me. Where would a sealer have been applied in these stages in your opinion?


...Well, they must have been thin coats of clear if they did three, since the gallon I gave them of clear has some extra in it and I still have it. Not alot extra, but some.

Well, the car has not been finalized as of yet. It was sprayed and it has sat in the sun or in the garage since them waiting for me to decide what to do with this now-rubstripless and sunroofless 1978 5spd. By finalized I guess I mean the clear has not been buffed or cut down in any way to smooth any clear coat defects (not many) and the occasional nibs. Would that process strengthen the surface?