urethane plus clear?

[Troy P.]

My painter was going to use a single stage urethane. But recently he said since the paint will have metallic it can't be color sanded without creating mottling in the metallic. Sort of makes sense. What do you think?

What if it was shot with clear mixed 50-50 with color. Could that be color sanded without mottling? The clear would still have metallic in it.

[Edward J.]

Re: urethane plus clear?

Troy, I painted my 63 with urethane and the gloss factor is very high by its self. no need for clear.

[Richard M.]

Re: urethane plus clear?

Edward, What color? If non-metallic I'd imagine he used single stage. Single stage is urethane base with clear added. Base is dull and requires clear topcoat.

Troy, Your painter is correct. Cannot use single stage as it will shadow the metallic when sanded and buffed. Base/clear can look like lacquer with the right recipe. A flattening agent added to the clear(up to 50%) is one way. Do test panels to get the desired finish.

Rich

[Gene M.]

Re: urethane plus clear?

Edward, What color? If non-metallic I'd imagine he used single stage. Single stage is urethane base with clear added. Base is dull and requires clear topcoat.

Troy, Your painter is correct. Cannot use single stage as it will shadow the metallic when sanded and buffed. Base/clear can look like lacquer with the right recipe. A flattening agent added to the clear(up to 50%) is one way. Do test panels to get the desired finish.

Rich

Not exactly what one should be looking for. The original paint in the 50's and 60's Corvettes had only a single stage recipe of lacquer. They definitely did NOT have a clear top coat. When buffed the the original cars had the shine in the color coat. That looks entirely different from a color coat with a top coat clear regardless if buffed or not. Also understand that metallic paint today has more particals than the old lacquers that were more "solids" looking. One is only fooling one's self implying that base clear metallic looks as original lacquer as it was applied at GM in the day. NCRS is very leaniate in evaluation of modern clear coat finishes.

In my observations if one wants an EXACT original looking without excuses single stage gets you closer. Word of advice choose a Corvette that was a solid color vs metallic to achieve a more realistic look and avoid clear coats. IMHO clear coat paint does not look correct period. Correct finish is not the goal of many, only the acceptance so point loss is kept to a minimum. Let's face it the appearance of modern finishes is far superior to the lacquer in the day as GM applied it and has become the new standard.

[Troy P.]

Re: urethane plus clear?

The issue is not the gloss but sanding and buffing on metallic would result in an uneven appearance as more or less metal "flakes" would be removed from different areas. Thus ending with a mottling. They did this that way with the lacquer at the factory though.

Would there be any advantage in mixing color with clear as a top coat to sand on?

[Richard M.]

Re: urethane plus clear?

The issue is not the gloss but sanding and buffing on metallic would result in an uneven appearance as more or less metal "flakes" would be removed from different areas. Thus ending with a mottling. They did this that way with the lacquer at the factory though.

Would there be any advantage in mixing color with clear as a top coat to sand on?

I would not recommend that. Same problem.

[Mark E.]

Re: urethane plus clear?

Color sanding and/or buffing metallic can cause mottling or an irregular looking finish. Lacquer has a satin finish when dry and typically requires color sanding and buffing to remove the orange peel and bring out the shine. That's why in the normal world (non-NCRS), metallic colors are top coated with clear.

Others know more about this, but my understanding is in lieu of using clear, St. Louis used heat to reflow the paint and provide an acceptable finish. This meant minimal buffing was required. It also meant significant orange peel remained in factory finishes. NCRS judging looks for the resultant "distortion of image".

Properly applied, modern base coat/clear coat finishes dry with good gloss and minimal orange peel/DOI. This enables most manufacturers to eliminate color sanding and buffing- a significant cost savings. But a BC/CC finish that's properly sanded and buffed looks amazing... mirror like with no DOI.

[Don W.]

Re: urethane plus clear?

"NCRS is very leaniant in evaluation of modern clear coat finishes"..not correct. My 69 is Riverside Gold it was repainted by the prior owner to RG with clear coat. I received a full deduct on paint and color at the Tacoma regional due to non lacquer appearance and clear coat.

[Bill C.]

Re: urethane plus clear?

I have done several cars and always did real well when being judged.

You can make BC/CC look very much like lacquer - you just gotta be creative as hell.

A good painter can leave peel in the clear.
don't wet sand it all unless to de-nib spots.
just cut once with compound
and finish with a polish like Finesse (one application)
don't do multiple polishings or wet sand, then you get flat glass appearance.


If the body panels are still wavy and you did something like I listed, it will have a decent look close to lacquer as possible.

use 40% flattener in clear for door jambs, front valance area and if applicable - the rear valance.

my cars always received the minimal deduct at regionals......
for paint.

Bill

[Gene M.]

Re: urethane plus clear?

"NCRS is very leaniant in evaluation of modern clear coat finishes"..not correct. My 69 is Riverside Gold it was repainted by the prior owner to RG with clear coat. I received a full deduct on paint and color at the Tacoma regional due to non lacquer appearance and clear coat.

New paint judging guidelines have more favorable options. Just because one car was detected as non typical and deducted for certainly does not recognize the 100's of B/C cars that get a favorable call. Saying that, an unfavorable call on one's car is definitely not the direction NCRS wants to go. Keeping owners happy is more important. Accuracy of restoration is secondary.

[Carl N.]

Re: urethane plus clear?

Have it judged in new concours class and paint can be whatever floats your barge !

[Jim D.]

Re: urethane plus clear?

New paint judging guidelines have more favorable options. Just because one car was detected as non typical and deducted for certainly does not recognize the 100's of B/C cars that get a favorable call. Saying that, an unfavorable call on one's car is definitely not the direction NCRS wants to go. Keeping owners happy is more important. Accuracy of restoration is secondary.

I certainly hope things have changed. I remember a prior post where 2 67 Marlboro Maroon cars were being judged side by side. Each one was a slightly different shade than the other, the judges in their infinite wisdom, gave both cars a deduction because they couldn't decide which one was correct. I'm sure neither owner was "happy".

[Gene M.]

Re: urethane plus clear?

I certainly hope things have changed. I remember a prior post where 2 67 Marlboro Maroon cars were being judged side by side. Each one was a slightly different shade than the other, the judges in their infinite wisdom, gave both cars a deduction because they couldn't decide which one was correct. I'm sure neither owner was "happy".

There had to be other reasons for deductions. Team leader Nick would not allow the reasoning you stated.

PS judges do not have "infinite wisdom".

[Dick W.]

Re: urethane plus clear?

Always added 10% color to the clear. That way when you cut and buffed if you went through one coat of clear, so what