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Paint Prep - Diving in head first

 
Old 11-10-2018, 11:06 PM
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mkriete
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Default Paint Prep - Diving in head first

Well, I finally did it. I took a sander to my car. I have spent the last 4 years getting my 1980 US A/T running and driving well. Iím now pleased with the performance and handling. The car needs to look the part. The current paint is awful and has failed. I have rust at the rear quarter windows, around the rear glass, on the roof, and front cowl. The car was originally Petrol Blue Metallic, but has be covered by a poor-quality black paint.

I figured I could share my progress. So here is my plan. I want to do as much work as I can myself, but painting is an art. Iím no artist. I am going to take it to bare metal and dissemble. Iíll have the bumpers blasted with walnut shells. Rub strips will be deleted. Iíll let a professional paint it back to Petrol Blue Metallic and reinstall the panels.

This car is my first attempt at a restoration, so I am nervous and anxious. The car is where it is today because of the excellent knowledge base here. Needless to say, I welcome any thoughts you may have.
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Old 11-10-2018, 11:11 PM
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I cannot get pictures to upload. I'll try again in a bit.
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Old 11-10-2018, 11:22 PM
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Here are some pictures from when I brought the car home.







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Old 11-10-2018, 11:29 PM
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And here is the start. I already found filler.


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Old 11-10-2018, 11:31 PM
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Old 11-10-2018, 11:36 PM
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dr bob
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Don’t take it to bare aluminum. Stop when you get to the anticorrosion coating on the metal.

Go go negotiate with your painter now. I’m pretty sure the value in your participation will be with disassembling and carefully cataloging bits pieces and fasteners. While diy sanding and prep sounds like a good use of your time, a pro body and paint place will have much better tools and skilled slave labor to do the paint removal. They will also use the prep chems that work with the car and the paint you choose.
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Old 11-11-2018, 12:14 AM
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Like Bob says, talk to the painter now, and have him guide you on what he wants you to do, and what he doesn't. If you know how to take the glass out, you can do that. If you don't know how, stop and ask. You've got a good plan. Tell the painter clearly what you expect from him. Plan to replace the bumper fasteners, and beading. Now that you've found rust, you'll find more. Have a plan to deal with that.
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Old 11-11-2018, 12:34 AM
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I have spoken with a painter. He wanted me to take it to bare metal. He preferred that I have it media blasted, but no slave labor in that. I planned to take this panel to him for his critique before I go further. He was going to prime the panels as I brought them to him.

I had suspected past damage on this panel, so I started here. I found damage worse than I thought. A lot of filler. The paint layers on the front of the panel were pretty sparse. The rear of the panel has thick layers of paint. Frankly, I think it may be easier and cheaper to replace the panel.

So, how do I know when I reach the anti corrosion layer on the aluminum? Is this the Grey-ish layer Iíve found just above the aluminum? Given the condition of my paint, I did not think it was feasible to save any of it.

Am i correct to assume bare metal on the steel panels? I donít see how else you deal with the rust.

This is why I love this place.
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Old 11-11-2018, 12:45 AM
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I didn't want to contravene what Bob said, but I always have gone to bare metal. There is work to be done repairing the rust. You may want to start with some aircraft stripper. By the time you figure in the hours of sanding, and the heavy sanding disks, the stripper might be better. I'm guessing you will find rust on the lower rockers. This is going to get pricey, so do what you can, and don't worry about the bondo. It's possible you can find a fender if one of them is just too bad.
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Old 11-11-2018, 06:03 AM
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Hi hears a can of worms. All to do with what products paint shop use's and how good there shop is air dryer in compresed air line . Good paint Glasurit . Stripping to bare metal all depends on how much and how many times it's been painted allways a messy job acid etch on bare metal .You have to media blast all the surface rust to eradicate it Navel jelly is a good rust eradication if you do not media blast on the front and rear PU bumpers plastic flexible primer is needed.
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Old 11-11-2018, 09:18 AM
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Rust deserves strip to metal for repair. Aluminum gets a protective undercoating within xx hours of exposure, before it builds its own barrier layer of oxidation. If you can avoid breaching an intact factory layer you avoid some of the recoating issues. If the is prior poor bodywork soon on an aluminum panel it will all need to come off anyway, so plan on replacing the protective layer.

Consider using chemical stripper so you don’t have as much sander damage to repair. Or media blast if you can.
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Old 11-11-2018, 10:25 AM
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One last thing, keep taking pictures for the album. If you ever sell it, the pictures of the process will make the buyer rest assured that you are doing it right, and not slap-dash. Good paint on a car is a significant investment. Most people don't do it right, but it looks like you are being very conscientious. Keep up good work.
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Old 11-11-2018, 11:33 AM
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Thank you again for your advice. I am already amazed how long it has taken to remove the paint on just this fender. The surface is rather uneven, which is making it difficult to remove all the paint. Iím using an abrasive paint and rust removal disk to remove the paint on a variable speed grinder, running at 3k to 4K rpm, as to not over heat the aluminum. The disk does not seem to take much aluminum off, but Iíve had to use 80 grit to remove the remaining paint. Of course this is leaving swirls. Oxidation is already forming as well.

I put up a tent in the garage to contain the mess, set a fan up at the garage door to pull air through the tent and downward. Yet I still have a coating of dust throughout the garage.

I have bit off more then I expected. I really want to put as much sweat equity into the car as I can. Iím not going to come out ahead financially either way, but I do want the experience. I agree this work could be done better and more efficiently by a professional. Spending the money on a car that needs $10k to become a $50k car would justify this expense in my mind, but not when itís a $5k car.

I know the car has been painted at least twice. I have found a lot of blue over spray on the car. The fender repair occurred before the black paint went on. Neither paint was done correctly (though the bondo work was well done). When I removed the bumper, I found broken lense pieces. It looked like the bumper was not removed to paint (really!?). I have blue and black overspray on the rubber seals (again, really?!).

To summarize the advice, the most care needs to be taken in removing paint from the aluminum parts. If there is not past evidence of repair, save the protective coating. The steel needs to go to bare metal and may need media blasting to remove all the rust.

So couple questions, will media blasting and/or chemical strippers remove the protective coating on the aluminum ? Is it best to sand to the coating?

Lastly, I suspect the front bumper struts have been compromised. How can you tell for certain?

Thanks for for listening!

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Old 11-11-2018, 12:43 PM
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Plenty of great advice^^The Just Peachy donor was also painted 3x before starting in on it and thankfully no signs of any damage. Chemically stripped then rinsed with a baking soda/water solution before paint. When taking down to metal, you may need particular type(s) of epoxy sealer over the galvanized and aluminum panels...ask me how I know. You don't want to do this twice so it may be best to contact "Kiln_Red" for his advice before proceeding. Austin has painted many 928's and knows the process better than I...pm sent T



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Old 11-15-2018, 04:56 PM
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does anyone know Austin's direct line? I sent him a PM but I don't know often he checks rennlist anymore...thx
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