Base Coat, Clear Coat, Scratches?

[Syncros007]

First off this is the first truck my father and I have painted. I am looking for some help on what appears to be fine scratches in the clear coat. What I have pictured is the tailgate off of a 1937 Dodge Truck. We painted it with PPG paint, which may not be everyone's favorite paint, but I had success all the way up until the clear coat. A rough procedure of what we did was epoxy primer, sand, high build primer, sand, color 3 coats, clear 3 coats (applied with in 24 hrs, so I did not sand the color), sanded with 1500 grit and 2000 grit, buffed. As you can see in the one picture from a distance the paint turned out well, but when close you can see what I think are fine scrathes, but not sure. I can not feel them at all. Does anyone have any idea if they are scratches, and if not what it is? How do I get rid of them, more sanding with 1500 and 2000 grit paper? Or sand, spray another 1 or 2 coats of clear, and sand again, and buff?
Any help, is much appreciated.
Thanks,
Kyle

[Jim_Edwards]

Buy an 8 oz. container of 3M Finish Restorer, P/N 030902. Use it all the time to take scratches out of our vehicles where the dogs have jumped up on the doors and fenders. Used to be able to get it at Wal-Mart but I haven't seen any lately. Most independent parts stores can get it for you if they don't have it on the shelf. An 8 oz. container lasts an unbelievably long time even as often as we use it.

It also works fantastically well with minimal effort on old oxidized original lacquer and acrylic enamel paint jobs.

Jim

[msmazcol]

What kind of buffing pad and what compound?

[Syncros007]

I used the 3M 6085 Rubbing Compound (Step 1) with a wool buffing pad Part No. MISHUD75. Then followed with the 3M 6064 Polishing 3000 Swirl Remover (Step 2) with a foam polishing pad Part No. MISHUD25.

[palosfv3]

The 2nd , 3rd and 4th pictures appear to show a lifting problem between the primer and basecoat. These defects appear to be under the clearcoat . Was the panel striped to bare metal or painted over an old existing finish? Depending on the answer , you may need to sand with 800 , recolor and clear or strip to bare and start over.

[Jim_Edwards]

After reading palosfv3's comment I'm inclined to agree that the problem is not with the clear coat and what we are seeing is certainly not scratches. Looks much like strange case of "orange peel." Humidity and temperature at the time any of the primer or base coats were shot could be the issue.

Sorry to suggest this, but I don't think you can fix it without taking it down to the primer or possibly even to the bare metal.

Jim

[Syncros007]

The tailgate and whole truck was stripped to bare metal, however the tailgate is the only piece we took the whole way through buffing, to make sure we knew what we were doing. As for the color, it seemed to spray fine, except when we sprayed the clear we did have a major case of orange peel. After speaking with the paint supply shop, we concluded we were spraying at only 20 PSI at the butt of the gun, instead the paint supply shop told us we need to be around 40 to 45 PSI at the butt of the gun. I had gotten confused because the PPG documents only tells you 20 PSI at the cap, and not at the bottom of the gun where our gauge is at. So we could have had bad orange peel in the color, and never knew it because we sanded the clear orange peel down until it was very smooth. Which I am beginning to conclude the color still could have had a major case of orange peel. Is that correct?

[Restorer32]

We are just South of York. If you'd like, bring the tailgate to our shop and I'll have my paint guys look at it and give you our opinion. We use PPG products regularly. If interested PM me for my phone# and directions.

[KenHupp20]

I agree the problems look deep,either in the color or primer.Perhaps not enough tack time on that part which trapped solvents.

[palosfv3]

Just for what its worth . Here is a link to the automotive paint troubleshooting guide at DuPont . The causes of the paint failure and the repair necessary are fairly consistent regardless of the paint manufacturer. Review and compare. There are good clear pictures to compare the problem area to .


Paint Defects Solution Guide | DuPont Performance Coatings - appp21.asp.dupont.com

[msmazcol]

Post number 8 seems to be your first key. If your base coat did not lay out smooth your clear cannot correct the problem. It only magnifies it.
Sorry.

That DuPont site is interesting information.

[poci1957]

No expert here but I also think trapped solvent is the likely problem, see "lifting" in the DuPont guide. Nothing you can do to fix it other than strip everything to below the defective surface and repaint, sorry to see it, Todd

[billybird]

I've been using PPG basecoat/clearcoat system for 20 years without a problem like you have. I'm thinking possibly, if you shot the clear at only 20 PSI it laid on way to thick. I always shot the B/C at 35-40 and the C/C at 50. Also I use 3coats of color and 4 coats of clear estimating to sand/buff off about 2 coats of clear. At this point you have nothing to loose. I would sand a spot very aggresively, buff and compare it to the surrounding area. If the "orange peel" is due to thick C/C this may solve it. If you sand through the C/C it will have to be redone anyway which the opinion of some of the above posts. As I said, you have nothing to loose at this point because you're not satisfied with it anyway. let us know how everything works out.

[msmazcol]

I would take restorer32 up on his offer. Professionals do this every day. They know the products and what can go wrong.

[palosfv3]

Be aware of the recommended reducers and dry times in regards to temperature, application windows between sealers , base and clear. I have seen similar problems occur when the base was applied beyond the application window of the sealer when applying wet on wet.

[martylum]

Hi-I'm a professional restorer and am afraid the problem is in the basecoat or even in the undercoats if you sprayed all of them at the wrong lower pressure setting. Most undercoats and topcoats spray out in the 40-50# range at the gun connection. I doubt any amount of rubbing of the clear is going to correct what appears to be a problem with the coats under the clear not drying properly.
Martin Lum

[Syncros007]

I am going to contact restorer32, it would be nice to have a professional set of eyes on it, in person. I do appreciate everyone's help. I am definitley not happy with the end result I got, so I do not have anything to loose by sanding it down to color and starting over from there. The epoxy primer and high build primer were sprayed at a higher pressure, it was my fault for interpreting the data sheet wrong and lower the air pressure.

From everyone's thoughts and input, my general consensus is we probably went wrong when originally painting the color and clear with to low of a PSI, and then only sanded and fixed the clear, but never sanded far enough to fix the color.

Also, that DuPont site is very interesting for an amateur learning, and seeing all the potential outcomes of various errors.

[palosfv3]

The DuPont site is also interesting for professional learning, and seeing all the potential outcomes of various errors..

[Bandit305]

In your first post you said you had sanded your epoxy primer before shooting your high build primer. I'm not a paint expert by any stretch, but my ppg epoxy primer data sheet says it should not be sanded. Instead it says to spray the next coat of finish within one week. If not, you are to scuf the epoxy primer and then apply more epoxy primer before the next coat. Could sanding fresh epoxy primer give you a problem? I don't know but my data sheet says you shouldn't.

Chuck

[Jim_Edwards]

Life sure was a lot less complicated with a couple of coats of red lead primer, a couple of coats of lacquer with pigment, and a few coats of clear lacquer.

Ah the good old days!

Jim

[Restorer32]

Amen brother! When we started in business in 1979 Lacquer primer was $11/gallon and black lacquer paint was $22/gallon.

[Jim_Edwards]

Amen brother! When we started in business in 1979 Lacquer primer was $11/gallon and black lacquer paint was $22/gallon.

Yeah, and aside from requiring a bit more physical labor done right those old finish methods would endure for a long, long time with little more than an occasional paste cleaner/wax job.

I just priced a gallon of red lead primer and nearly fell out of my chair. $185.00 a gallon. As stupid as it may sound I have a car that I'm going to repaint shortly and given it is from the '50s I think I'm going to do it as near the old fashioned way as possible with red lead primer and acrylic lacquer. Extra work be damned!

Jim

[Restorer32]

With lacquer you could paint a car with a broom on a windy night in a barn with a dirt floor and still get a decent finish.

[Jim_Edwards]

With lacquer you could paint a car with a broom on a windy night in a barn with a dirt floor and still get a decent finish.

Sounds exactly like my "paint booth"..........

Jim

[buick5563]

Sounds exactly like my "paint booth"..........

Jim

Mine too.