Color Sanding, 31 Cabriolet Just Painted

[Ed in Maine]

I have just finished painting my cabriolet with acrylic urethane. I had a paint run and some minor orange peel. I have been successful in removing the "run" using 1500 and 2000 sand paper using water and liquid soap. Now, how do I remove the scuffed appearance left by the 2000 paper? What procedure and products should I use to get the final, high gloss appearance?

I don't want to use a buffer. I am afraid that I will burn through the paint and have to re-paint a panel. With the edges and belt line it would be very easy to wreck the paint job with a buffer, especially when I do not have the experience using a buffer. I would rather spend the time and get to the desired outcome by doing the work by hand. What do you recommend? Thank you for your suggestions. Ed

[todd3131]

You will need to take it to 3000 grit and get a buffer you will never get the finish you want without it. Go to griots garage they have some nice packages for buffers compounds and foam pads don't use wool pads or you will bun through. Wool is for experts

[lrf]

Ditto on Griots products, used their bottled rubbing compound with a soft foam pad and adjustable speed buffer on a self painted enamel paint job and it turned out Jaw-dropping great! Yes, stay away from the edges or mask with tape then finish by hand. Good luck.

[todd3131]

If you would like I can take a few photos of my setup buffer pads and compound for you. Also if you would like I could send you a link to a web meeting and show nuou how to buff out the paint. Just let me know.

[chrs1961815]

3m compounds are the best IMO. You can buff it out by hand, but you are going to be there a long long time.

[J Franklin]

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Rub it out by hand and get some good exercise!

[BRENT in 10-uh-C]

Originally Posted by Ed in Maine

I have just finished painting my cabriolet with acrylic urethane. I had a paint run and some minor orange peel. I have been successful in removing the "run" using 1500 and 2000 sand paper using water and liquid soap. Now, how do I remove the scuffed appearance left by the 2000 paper? What procedure and products should I use to get the final, high gloss appearance?

I don't want to use a buffer. I am afraid that I will burn through the paint and have to re-paint a panel. With the edges and belt line it would be very easy to wreck the paint job with a buffer, especially when I do not have the experience using a buffer. I would rather spend the time and get to the desired outcome by doing the work by hand. What do you recommend? Thank you for your suggestions. Ed

Ed, continually using higher grits of media to level the surface is the trick to a high-gloss finish. 3M now offers grits to 8000 which almost leaves a polished finish after use. For your application, I would go to 5000 grit which will eliminate much of the need for buffing.

Additionally, the 'safety net' for you using a buffer is to use 1" masking tape and go around every edge or raised section of the panel with a layer or two of tape. This means the buffer can only reach within 1 inch from the edge of a panel. There is no need to worry about burning at that stage. If your buffer begins to burn thru or tear the masking tape as it goes over the top, then stop and add another later of tape to that area as additional protection. Once all open areas are worked, then peel the tape and hand work the perimeters.

[Ed in Maine]

Thank you all for your excellent comments. Ed

[Kevin in NJ]

It should be noted that buffing a good paint job actually slightly dulls down the shine. This makes it look a bit more like a factory paint job as the lacquer was never as shiny you can easily get with modern paints.

[J Franklin]

Kevin, I don't think the factory jobs were more dull.

[chrs1961815]

Originally Posted by Kevin in NJ

It should be noted that buffing a good paint job actually slightly dulls down the shine. This makes it look a bit more like a factory paint job as the lacquer was never as shiny you can easily get with modern paints.

This is just simply not true with any paint - enamel, urethane, lacquer, or single stage and base clear. Respectfully, this is misinformation.

[BRENT in 10-uh-C]

Originally Posted by chrs1961815

This is just simply not true with any paint - enamel, urethane, lacquer, or single stage and base clear. Respectfully, this is misinformation.

I also agree, but where I think the confusion may be is if there are micro-scratches remaining from the colorsanding process, then theoretically it could appear duller than untouched paint sprayed from the gun simply because of light refraction from the scratches. If the surface of the paint is sanded fine enough where the scratches are hard to see with a naked eye, the sheen should be the same.

[Hitman]

Originally Posted by Kevin in NJ

It should be noted that buffing a good paint job actually slightly dulls down the shine. This makes it look a bit more like a factory paint job as the lacquer was never as shiny you can easily get with modern paints.

I agree, and it's well known. I'd describe it as loosing some of the depth of the wet look or gloss. It's minimal, but it does it to some degree.

[Kevin in NJ]

I learned about this from Marco. I observed this on my car.

I used Concept single stage paint. I am not the best painter so I had to color sand. The areas where I laid down great paint the depth and shine were out of this world.

Paint that is able to form a liquid surface will be virtually void of scratches. As soon as you do a buffing process you are essentially sanding with very fine sandpaper causing scratch. It is subtle, but there.

I do not have the correct numbers handy, but the laquer of the 1930's was not very 'pure' and had about 80% reflectivity.
The modern stuff sprayed well is in the mid 90's and buffed it gets down to like 90%.
Again I made up the numbers, but that is the idea.

Marco flattened the paint on areas like the firewall and door jambs. It buffed out the exterior just to lower the reflectivity to do his best to get and original patina. He was clear that it still was much glossier then some of the original untouched cars he has inspected.

[31Cabriolet68-C]

What color are you using? Can U post pics of the progress?
Very exciting part of the work...
Congratulations on getting so far, and so fast!

[BRENT in 10-uh-C]

Originally Posted by Kevin in NJ

I learned about this from Marco. I observed this on my car.

I used Concept single stage paint. I am not the best painter so I had to color sand. The areas where I laid down great paint the depth and shine were out of this world.

Paint that is able to form a liquid surface will be virtually void of scratches. As soon as you do a buffing process you are essentially sanding with very fine sandpaper causing scratch. It is subtle, but there.

I do not have the correct numbers handy, but the laquer of the 1930's was not very 'pure' and had about 80% reflectivity.
The modern stuff sprayed well is in the mid 90's and buffed it gets down to like 90%.
Again I made up the numbers, but that is the idea.

Marco flattened the paint on areas like the firewall and door jambs. It buffed out the exterior just to lower the reflectivity to do his best to get and original patina. He was clear that it still was much glossier then some of the original untouched cars he has inspected.

Again, there is some confusion in this. The reason why many aged lacquer paints do not have the sheen is because the oils have evaporated over time and caused the paint to 'dry out'. They were much glossier back in the day, and this can be proven by comparing freshly sprayed Pyroxilyn or Nitrocellulose lacquer paints.

Regarding Marco's technique, there for awhile the trend many of us trying to restore to an authentic look was to add the 4985 flattening agent trying to mimic the 'unbuffed' nitrocellulose lacquer look of jambs and under-body areas. The problem was it would tone the sheen down however it wasn't replicating the look of the lacquer. Terry Deters (-who often is the Area 14 Team Captain at MARC meets) and I discussed this at length one time when I was trying to authentically (-at least aesthetically) paint a 76A pick-up. I wound up spraying some old Ditzler lacquer in the two-step process as described in the Paint & Refinish Guide to see what I needed to do to replicate it using PPG's DCC line. As Kevin is saying, the depth of the paint is not close to Nitrocellulose lacquer however I don't think it has to do with the pigment quality per se', but with the micro-scratches in the paint that refract the light. Even with flattening agent added, the texture was different even after colorsanding and buffing between urethane and the lacquer. The closest I was able to replicate it was to spray enough DCC urethane to achieve complete coverage and then allow to flash dry. Then using a hot lacquer thinner in lieu of any DT*** solvent, I used a hot Lacquer thinner to catalyzed DCC paint and fogged one medium coat within the re-coat window. Because that paint was not going to be colorsanded nor buffed, the lacquer thinner for a solvent caused it to take on the sheen and texture much like freshly sprayed Nitrocellulose lacquer paint.

One final thought when trying to replicate the original texture and sheen, the paint was actually colorsanded originally using a coarse paper (-something like 220 grit) with the intent of only knocking out any runs, dry areas or blushing. Then a solvent (-likely a lacquer thinner with lots of retarder added) was sprayed onto the dry paint and it softened the topcoat allowing the paint to soften and flow into some of the scratch marks. From there is was allowed to dry (-which happened quickly) and then buffed. Likely the heat induced from the wool pad also allowed the paint to soften and reflow. For those of us who have used lacquers on custom show vehicles in the past, we know that we can achieve very deep sheen using lacquer toners and clears.

[Marshall V. Daut]

Here is a paint job I did 11 years ago with catalyzed PPG Concept paint, followed by 1000, 1500 and 2000 grit sandpaper before buffing out with a lamb's wool pad. How dull does this look?
Marshall

[Kevin in NJ]

The pigment quality is something I learned about as I learned about the paints.

In a nutshell chemistry improved considerably and they are now able to produce more 'pure' colors. Plus I would also imagine they are able to produce the actual paint more 'clear'.

So trying to get the 'correct' tint of a modern paint takes a different formula then what would have been done in 1930.

In the end, it requires a lot of experimentation by experienced people to get close to 'factory' tinting. With the cost of paints today it is likely not something the average person can hope to get correct without significant costs.

From the perspective of an average hobbyiest the most cost effective way to get 'close' is to buff out the body. Which in all honesty you are going to need to do anyway becuase of the minor screw ups you are likley to end up with when you are done.

Painting was frustrating for me. The paint was not as pricey as it is today and I was afraid to mess it up. So of course I did mess it up. In the end I have to say, I really suck at getting paint on the car.

[Ed in Maine]

Thank you all for your comments. Over the years I have used enamel, lacquer, acrylic enamel and finally acrylic urethane (from TCP). This paint is expensive but the end product is wonderful. It seems sticky such that with care it doesn't run easily. This past time after not painting for a year, I lost my head and had a run right out of the gate and in full view too, right behind the door jam in the quarter panel. Oh well, I recovered and the end product was pretty good. What is amazing to me is that overnight this paint becomes shiny and hard just like glass. The car becomes encased in this paint! My colors were the Ford greens, Kewanee and Elkpointe. The paint sequence was epoxy primer, high build epoxy primer, epoxy sealer coat and finally 3-4 coats of urethane top coat. For the Cabriolet it took less than 2 quarts for each color. I have decided not to go back and total up the receipts!
I did have problems coming up with the tints I wanted. I used a computer based program on the internet that mixed colors by volume. Then with "nerves of steel" I purchased quarts of yellow, blue, white, green and black from TCP and mixed very small batches until I had a color mixture that was pleasing to me. After spending so much money, I wasn't sure I would end up with a color I liked. But as I added the last color component, the Kewanee color just jumped out at me just as the computer program predicted. When I had the lighter green color (Kewanee), I just started adding black until I had the accent color (Elkpointe). I ended up mixing 3 quarts of Kewanee and 2 quarts of Elkpointe. On the car, the colors are perfect to me. Thanks to so many of you during my research for this painting project. It is sad because I am at the end of my painting projects. I am too old to get into this again. When you finally get it right, its over. Ed