delamination: ppg single stage/3M Schutz rubberized undercoa

[zgeezer]

Do I go back to step one?

 

Here's my product list applied to underside of pan and wheel wells.

1. sandblasted to clean metal

2. POR silver (one coat brushed)

3. POR TieCoat (one coat brushed)

4. Cascade sound deadner (one coat spray, rough finish, not rubberized)

5. PPG "sealer" primer (don't remember product #, recommended by PPG sales shop) sprayed.

6. 3M Schutz rubberized undercoat, sprayed 4 quarts for under pan& wheel wells;

7. PPG "sealer" primer (same as above) and

8. Single stage PPG color.

 

(Eight different coats...now I know where all my time has gone )

 

The car has been stored outside in low desert of CA , on its side. The PPG sealer and color is beginning to delaminate from the 3M undercoat along the bottom rocker panels and interior front wheel wells. These locations receive a lot of sun and are not shaded. Do I have a problem with the 3M rubberized undercoat or have I screwed up elsewhere.

 

Is this a problem with storage? It's been about 18 months since the final color coat was sprayed. The delimination is showing up within the last 3 weeks.

 

Any comments? May be 8 layers of anything would delaminate.

 

I need some help on this b/c outdoor storage is all I have and I hope to spray first of three stages of color and clear on the rest of the body b/4 I begin assembly. It'll take another 18 months to finish the project and roll it into my garage.

 

help.

 

g

[zgeezer]

I applied the Tie Coat nearly 2 months after the Silver POR15. The POR was cured. The Cascade product is VB-1X (loooove these designations) see : http://cascadeaudio.com/prod/vb1x.html. It appears to be a petroleum product. Their tech states that it can be painted over. I applied the primer over the Cascade product about two weeks later. I've pulled off a sheet of the finish coat and it appears to be delaminating at the 3M/PPG primer interface. I primered the 3M product another 3 weeks after having sprayed it. This location is one of the hottest places in the US, [yeah, I know Arizona and Texas are h.a.h. but do they have towns called Thermal or Mecca?] Sorry, I digress.

 

The zones of delamination are all on the upper surface and begins with 1inch square "crazing". I hope this is a weather exposure problem, but if it's preparation or contamination I need some insight into prepping 3M Schutz for paint.

 

Finally, the POR rep talked to me and his opinion is that the Top Coat is delaminating in sheets b/c of contamination in the application. He suggested that the product was reduced with an inferior thinner. [it was applied straight on without thinner] or than the POR15 should be sanded or otherwise "roughed up" with a nylon pad.

 

I'm going to clean up and respray the Top Coat.

 

Redundant? How dare you say that, when you've not even seen the other 9 coats of product on the inside. Ask me to explain why I have three sets of everything, have taken two quarter panels up and back down to bare metal twice. Only my shrink knows...my wife despairs. Friends have died, married, divorced and remarried, while I continue with body work. I, too, seek the grail. Sorry, I digress.

 

g

 

g

[zgeezer]

ooooooooooohhhhhh, I was afraid I'd be doing this again. Practice, I'm told, does make perfect. Fortunately, I've still about 2 gallons of POR stripper in the back room.

 

I appreciate the help. Great site, but too many great ideas, for a grease junky that lives vicariously off other's great rides.

 

g