cut and buff question

dlamm

Junior Member
Just painted my 1930 model A pickup with a D/T urethane primer, base coat and gen tec clear. It looks good but I am not comfortable with the sand/buffering process. Is there a problem if I leave it in the clear?
 
Just painted my 1930 model A pickup with a D/T urethane primer, base coat and gen tec clear. It looks good but I am not comfortable with the sand/buffering process. Is there a problem if I leave it in the clear?

Nope. All that colorsanding and buffing does is makes a nicer finish.
 
you might consider just paying someone to do that last step for you- who is experienced. the difference in finish can be huge.........
 
My car never had a color sand or any buffing and I like it better that way. I think it is closer to a factory finish.
 

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My car never had a color sand or any buffing and I like it better that way. I think it is closer to a factory finish.

Ahh, but wouldn't you agree the factory actually did color sand and buff the bodies as seen below by a couple of assembly line workers. Because of that, I would think that colorsanding & buffing would actually more closely replicate a factory finish.

509654



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DL, if you are happy with the way the car looks then you 100% can leave it alone as is.

If you want, this would give you time to do 2 things.

1: take your time and learn sand and buff techniques.

2: shop around for some shops that could do it for you.
 
Some would consider that there might be a good reason to lean towards keeping as much finish on the car as possible as opposed to taking some back off (and risk going through the clear, not hard for us amateurs to do, sometimes I have to recognize my limits and not screwing something up trying to get it perfect (just my $0.02 (which really isn’t worth even $0.02). If you do decide to take it further wait at least 30 days to let your finish really cure.
 
Two things to consider;
Paint chips and/or cracking in the paint can generally be contributed to excessive of mil thickness . Often times, less mil thickness of the paint creates a more durable finish. As mentioned, recognizing limits is a good thing however it is my experiences that if someone is paying attention and only sanding enough to remove the 'proud areas' of the texture only, then it should not be an issue about sanding thru. When in doubt, use a finer grit sandpaper and check your progress often.

Second, consult the paint manufacturer about the colorsanding window. Some paints will continue to harden so much that waiting for 30 days can be outside of the recommended sanding window and the paint basically becomes too hard to effectively sand. To achieve a good finish, we often colorsand within a day or two from spraying with 2,000 grit. After a few days to a week we move to 2,500 and/or 3,000 grit and continue to let the solvents evaporate. Often times we finish sanding with 5,000 grit only to let the solvents fully evaporate for an additional 4-7 day timeframe prior to beginning the buffing process. When this is done, the sanding and buffing is completed within a 2-3 week window.
 
Brent, as youre mentioning 5000 grit- I had no idea there was that fine.


what would you guess the factory sanded down to- as Im guessing it was nowhere near 5000?
 
Brent, as youre mentioning 5000 grit- I had no idea there was that fine.


what would you guess the factory sanded down to- as I'm guessing it was nowhere near 5000?

Actually we go to 8,000 grit on show car finishes. The buffing pad is carrying media mixed into the rubbing compound. Because the foam (-or lambs wool) carries the grit (media) it can be applied at different pressures during each revolution of the pad whereas if the person doing colorsanding is using the correct technique with a backing pad that is flat, the paint is actually honed to a fine, and flatter finish.

Ford used a different type of paint than what is typically used today. Lacquer (-or Pyroxilyn as it was called back then) was a totally different product, ...and it did not use a hardener to make the exterior shell stronger. Ford's procedure was to first wetsand the Pyroxilyn with 240 grit (-IIRC) and then follow-up wetsanding it again with 320 grit. At that point it would have been fairly slick however Ford Engineers then specified for the painter to use a hot thinner and spray the entire body to melt the Pyroxilyn and flow out filling in the 320 grit scratches before/as the solvents evaporated away. A that point, there was not any orange peel or paint defects (-such as runs) remaining in the paint, so it was pretty slick even prior to the buffing wheels going over the entire paint surface.
 
I will often sand to this grit or even finer. It allows you to slow the buffer speed down a bit so you don't get as warm with the buffer.

Yes, that is true. Most of us now use an electric DA Orbital Polisher when buffing and final polishing. Gone are the days of using a old heavy electric buffer with a wool buff that actually got the paint hot enough to melt or soften.
 
Cut and buff reminds me of the plating business 45-50 years ago with my Grandfather. I would "help" him with polishing and Buffing and remember the term "cut and buff" he used also referred to paint finishing.
He told me once he was gone I was to pass on the knowledge. I appreciate the value of people today that listened to their Grandfather and are helping our hobby today.
As my father always said "these are the good old days"!
 
It does make for a nicer paint job. From the Judging standards they where polished to a 80% gloss level using a reflectometer. Now all you have to do is find one of those.
I always let the paint cure for at least 2 weeks before I polish. It's one of those things where everyone has there own way. I'm old school I still watersand by hand. 1200, 1500, 2000 and 2500. Then polish. Here's pictures of a 31 Tudor I'm working on right now.
It's a Canadian car, back init's original colour. "Classic Blue and Black" it will have a cream stripe.
 

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