BC

Thanks for the offer Oscar, but the car is a shell roller right now. Its fate is somehwhat tied into whether this paint experiment has deemed the surface too fragile to drive daily.

Bill Ball

I have no technical knowledge of paint, but I will say the factory paint from the 80s is the hardest I have seen on any car I have ever owned. Isn't it catalyzed urethane? When I use polishing agents on my 89 that would work on any car other I've had, like 3M Finesse It-II, nothing happens.

BC

I agree. Do we not have materials that can do this anymore?

Daniel Dudley

I had similar issues with chipping on a car I assembled 9 years ago. Had to be real careful with the surface. 9 years later, the paint is still fine. I think that was PPG as well.

I would be tempted to tell you to seal the chips. You are a meticulous guy, and this must be making you crazy. I felt the same way 9 years ago, and the paint is holding up fine. Take your time evaluating this. Chipping is one thing, flaking is another. Heavy objects . UGH !

slate blue

Brendan painting a car for the first time can be difficult, big learning curve, first in future I would never remove the factory primer on the steel panels unless there is a need, you don't want to damage the galvanizing. As many have said more is not better especially in the area of paint. A gallon of clear is too much, now I know you said you have some over.

I sprayed my Iris blue S2 earlier in the year, three coats of MS clear used 3.5 liters to 4 liters as we had to redo some parts. (I wanted it perfect) Now if you used 4 liters of HS (high solids) clear that is too much.

Nothing will change the paint now, the sun is the best baker, you need to make a decision on what to do how your paint stands now. If you put on the paint work a very sticky tape or even water blast it, not too close mind you, one the paint shouldn't come off two the water blaster shouldn't leave any marks. I mean this is how I cleaned up the door jams and hard to get to gaps after all the buffing that you have to do after fully repainting these cars.

If it comes off you have your answer, you will need to redo the job, if not that paint should be fine. I don't think dropping spanners on the paint is a good way to tell. BTW to all those out there who wonder why the original paint is so hard, the paint isn't two pack, that is used with a hardner, it is baked enamel, high temperature sends the paint off, the car doesn't have an interior in it so heat isn't a problem.

Cheers Greg

Pfunde

When I had mine done, the paint guy told me that he would only paint it in high solid color, and only with silicone in it. Otherwise he said I would run in to all kinds of problem due to the stuff they used to put in carpaint. I wanted a color that was a grey metalic + clear, but he told me it would look horrible as soon as it was heated by the sun or anything else. In fact, he wouldn't use heat in the paintbox - he was affraid it would make somekind of chemical reaction....!
Mine still looks like new

JHowell37

Brendan as you can tell, if you ask a question about paint, everyone will have a different answer and nothing is absolute. I can't access the tech sheets on PPG paints so I can't say what's what. As a general rule, you don't want body filler to contact etching primers due to the acid contact reacting with the filler. Whether the epoxy was meant to to go over the etch, I don't know. Most modern epoxies have phenomenal adhesion to all metal surfaces (but they should not be used on plastic) and etching is not necessary or should be avoided. So it sounds like most of what you read online is correct.

As for sealing. I'm using Glasurit on mine and the smallest container of epoxy is 5 liters. Add the catalyst and other stuff to go with it, I'm going to have over 8 liters of sprayable material. With the Glasurit you can mix the epoxy to be used for adhesion, high-build, sealer, etc. For my high-build I'm going to use spray polyester. I'll have to seal the entire car, my feeling is that it should always be used on the entire vehicle prior to topcoat.

You can still rub and cut the paint. Even though it's fully cured it can be done, it's just more difficult to do when when the paint has acheived maximum hardness. I'm afraid I'm not going to be of much more help simply because I'm not where you are, and pinpointing paint issues is always a crapshoot.

slate blue

By JHowell 37
I have found that by using a cheaper paint, it doesn't always end up cheaper, when I used standox, another paint used by the factories in Germany I knew that it was a cheaper paint than Glaz but I thought I could save a few bucks, I was wrong, I ended up using more product. In fact I weighed the high build primers and the litre of Glasurit weighed 1.9 kg and the litre of Standox weighed 1.7 kgs. Weight may not be everything but I think it is an indicator.

I also agree with you on the etch primer front, need to be very careful how you use it, especially with filler. I also think you need to be careful with spray on fillers as they can be brital. I don't use them, I always pay a beater to do a panel work that work require this so that only the high build primer is required, save on the product pay more for the labour, also the risk of sink backs is avoided. I realise that not everybody wants or needs to do a job this good though.

Cheers Greg

BC

I was trying to put a professional paint job on the car. Other then my choice to spray PPG I didn't see anything I did as a cost saving device, other then of course I did it myself up until color.

Warren928

I have been doing autobody and custom sign painting and building for 17 years, and maybe my advice can help you.
Sanding the aluminum surface with at least 180 for using filler.
sanding the filler to a 320 grit finish before primer/sealer. I used a primer sealer product that was zinc based and could not bne used on fillers, instead I used a basic automotive grade general purpose primer over those areas (and steel) and blended the two different primers. pinhole filler went on next. then 320 the first coat or two of primer and the final coat of primer had 400-600 grit sanding.
Cheese cloth the final primer sanding, dust free environment, downdraft booth at 75- 80 fahrenheit and low humidity is ideal.
2-3 light coats of top coat, following directions on can for what the "flash time" should be, generally between 15 minutes and 45 minutes. If there is a clear, time can be critical for applying the clear depending on the system.

If applied too early, it could be brittle or lift the metallic flakes. If applied too late, it could be soft and experience outgassing.
Messing up one or more of the chemical interactions or other preparation steps can result in a soft, brittle, or lifting situation.

Yeah, it sucks-- ask me, I have seen it happen on many an occasion!

danglerb

What does the place that sprayed the paint have to say about it?

fst951

Read into the epoxy primer data. I suspect that the 600 grit is too fine for good adhesion. How long did the epoxy sit prior to top coats? I also assume that you put your bondo or platic filler over the epoxy, correct? It is very hard to adhere to epoxies after 24 hours if you do not provide mechanical etches. Also you need to blow off and wash down the epoxy after it is sanded in order to remove all the sanding materials from the scratches. I would bet money it is the in the prep. You have two different issues, improper primer preparation for the top coat and if the top coat is still soft, it may have had too little hardener applied or applied too thick. Just my guess, but I paint a little as well.

BC

Each step was mechanically etched with the proper sandpaper per the directions on the data sheet for the product. Meaning the DPLF, if let to sit for a certain time, must be sanded and DX'd (paint prep- high evaporation) prior to another coat. The High build primer was the same way. All the blocking was done on the high build primer. I had a painter helping me with all prep and primer stages, and then the car sat for a while before the color and clear. The shop that did the color was prepping the car for color with 500 and 600 I think, which is what the high build asks for before color.

BC

I am not clear on what you are saying, but I would like to understand.

BC

[QUOTE=Greg Gray]
Nothing will change the paint now, the sun is the best baker, you need to make a decision on what to do how your paint stands now. If you put on the paint work a very sticky tape or even water blast it, not too close mind you, one the paint shouldn't come off two the water blaster shouldn't leave any marks. I mean this is how I cleaned up the door jams and hard to get to gaps after all the buffing that you have to do after fully repainting these cars.
[/QUOTE

This is very good advice greg, thanks. I have attempted this this morning with the pressure washer, which is 1300 psi. I sprayed all the edges where it could flake, but was too concerned to spray directly at the chips I have mentioned. I will attempt this daring feat tonight or over the weekend and report back. When you say tape, do you mean like Duct Tape? Or what I call silver tape?