Wetsanding and Compounding issues

A

airjames

New member
Buddy of mine has a mid 80's Dodge Ramcharger. It's a full size sport ute he's working on to make a street truck. He recently did some paint cleaning up on it. The truck was completely repainted with a cheap paint job and it was full of orange peel and drips. Couple days ago he wetsanded the whole truck with 1200 grit sandpaper and compounded with FI III I think it was or FI II, not sure which one and used a rotary. He showed me pics of the truck and it looked just awesome. Crisp, clear, like a black clear mirrior and no more peel. He waxed it with MEguiars Cleaner Wax in the marron bottle.



Next day over AIM he tells me the truck is dulling back again, the shine is fading away fast and looks like dog crap. What could cause the paint to fade away and dull out so quickly??? He's an experienced 3M detailer and says he's never seen anything like this before. The truck is black non clearcoat acrylic paint. Any suggestions??? Thanks all,,,,,,,,91:up
 
I have wet sanded many of cars but never had an issue like that.



I was going to say that he damaged the clear but you said that there is no clear on the car.



You say he is experienced but has he wetsanded in the past.

You can damage the paint very easly if you go to far with the sanding.



He may have some residue left from wetsanding on the car.

I always like to wash,wetsand, compound, wash, polish, wax.



He should try to wash the car and use a heavy polish and see what happens
 
Well if you wet sand then shine the paint without removing all of the sanding marks the paint will look new until the protectant fades away then it'll look dull, hazed or grey.



I'm sure he knows this but he needs to compound then polish. The paint should have a decent shine before he applies the protectant.
 
I suppose one way to find out if he got the results for [as he is working] immediatly would be to wipe down with alcohol...I think 1:1 alcohol, water ratio is suggested here. Maybe a quick wash with dawn wash would be revealing as well.
 
seems like he should have done another step beyond 1200 grit. maybe 1800 or 2000. sounds like he might have just buffed it out and waxed it up immediately so it always had that "wetness" to it, even though the surface now has a matte finish. as the wetness is drying out, the finish is looking worse.



that's my theory at least.
 
Here is the article on proper wetsanding:



Wetsanding article



You do have to repeat with lower abrasives when wetsanding or the compound only cuts the high surface areas and cannot get below the areas that are left.



Once it's wetsanded down to 2000 grit, follow with Diamond cut or 3M P-II rubbing or 3M Imerial Microfinshing then keep going down in polishes until glossy and smooth.



Regards,

Deanski
 
Dido...



In fact they now have 3000 grit...but I would use nothing less than 2000...with alcohol wipe in between...
 
FWIW I have not had great results with Meguiars Cleaner Wax (tan bottle though). It seems to wash away rather quickly leaving behind some of the swirls it was hiding,
 
If it's single stage paint (non clearcoat) then that's the problem.



You CANNOT wetsand single stage that way, and he obviously didn't know this. What has happened with the dulling is called "die-back". It will continue to happen over and over again. You will polish it back, it will dull in a short period of time, Repaint is the cure.



Single stage enamel has glossy resins with UV that migrate to the upper .5 mil of the surface, providing the durable shine. When he wetsanded, he removed most of those resins, along with protective UV.



There is a saying in the body shop biz that goes ; "With single stage-what you spray is what you get" No second chances. Runs, orange peel and dirt can't really be removed the same way as with clear. This is why you must spray single stage in a clean downdraft booth, and spray it right, because you must live with the mistakes or sand it down and repaint. That's just the way it is. Generally detailers don't know this, but should. I have a background in auto body since I was 17, and painted quite a few cars, so I learned this years ago.



This is why base/clear is the only choice for the novice because you can sand out runs and orange peel. You still can't sand away tons of clear because you have UV in it too, but it's much more forgiving than single stage.



Sorry to be the bearer of bad news, but ...live and learn.
 
In essence, yes. The more of that surface gloss you remove, the more pronounced the "die-back" will occur.



This is common knowledge in the auto body/paint industry, but evidently not in the detailing industry today. I would guess the cause is due to the high percentage of base/clear paint on today's cars and the very small percentage of single stage. The oldtimers know this ( that's scary-i'm only 46! I guess I'm one of them, lol ) but if you aren't accustomed to seeing and dealing with single stage, I can see how the info would escape you.



If you had someone spray something like IMRON real well, and you didn't need to compound it out, that paint would last and shine forever. Once you cut it good though, you'll be polishing it back to a gloss on an ever increasing basis, until you have to do it so often a repaint is the only remedy.
 
I guess automotive paint has become alot more durable.



If it makes you feel any better, I think my father is your age ;) I'll be 22 at the end of this year.
 
and on the topic of single stage for those of you who have a toytoa or lexus and the color is black, paint code 202. depending on the year of the vehicle it may not have clear coat.

Not sure if this was changed by them yet or not.
 
My 1993 Lexus SC400 doesnt have a clearcoat. Does this mean it is single stage paint and I cant wetsand it? I have some etched in water spots and tree sap marks and i think wetsanding is my only option.
 
NP, you don't have to agree, I am not "the" expert here, just passing on info from the real experts. Since you have put me in a defensive position, I will provide my own links to support this.



What you posted from Sherwin Williams is just part of the story, the technical side on application dullness issues with newly sprayed paint and the causes. Some of the people on this board have posted about perfectly fine paint (new and old) until they sanded it etc. and found it then required polishing much more often after that.



What I have explained is what body shop professionals will tell you about cutting SS hard, and my own experience in the detailing field. I have gone through the learning curve on this more than a few times, with unhappy customers years ago that called me back a couple weeks later about dulling. You learn real fast when it comes to your door. There are a few master painters on the below forum with the same experience who have warned people about it also, so it's a know issue, not something I am trying to accept credit for discovering. Here is one such person;



http://www.autobodypro.com/wwwboard/messages/4546.shtml



And yet another;





http://www.autobodypro.com/wwwboard/messages/4612.shtml



In this link;



http://www.autobodypro.com/wwwboard/messages/4613.shtml



please read this paragraph well;



I know everyone has already said this , but... Never sand single stage paint as you are removing the very thin layer of clear that floats to the top and leaving nothing to protect your finish - unless your really into weekend waxing projects... lol It just makes me cringe when I hear someone wants to sand or even buff single stage. Body shops may do this because it temporaily looks great while the customer is paying his bill, but it's your car and you want all the UV and long lasting shine you can get - please don't buff your limted single stage protection off. Runs have to be sanded down and repainted, sorry there is no other fix ...
Click to expand...



Paint by nature dulls from exposure to sunlight, we polish, it shines. We repeat this a number of times. You get to do this process until you remove the UV and glossy resins at the surface of SS. That can take many years, unless you compound regularly or wetsand it. Wetsanding it is just asking for a quicker demise.



Now go here;



http://www.autoint.com/O.E.M. Clear Coat vs. Heat page 1.htm



and scroll down to "THE FACTS" paragraph. It will explain how removing more than .3 MIL of clear can lead to it's demise. SS is affected a bit differently in the "die-back" issue because it's pigmented, but the UV can nonetheless be removed the same way because it's in the surface also . Although clear is unpigmented it's aggressive removal will as well result in failure of the film build. Sherwin Williams may not address the UV issue in their list, but I can assure you the people that supply oem finishes to the manufacturers (of which S/W is one) sure do in technical data, according to autoint.com.



If you are negating my opinion and experience on this topic I don't feel so bad, because you're throwing in MANY professional body shop painters and technicians in with me. No hard feelings if we just disagree, but I stand firm on my posts regarding this subject. It's not "to be right', it's to save people from heartache and a lot of $$$. Cheers.
 
As an owner of a 2001 black toyota 4runner i am reading this with interest. I did some digging and believe the paint on the vehicle is single stage. What would be the proper method of maintainig it? A glaze and wax since I have been reading not to use abrasives?
 
Same question as above, with an added twist. If said SS paint is generally ok, with some swirls, but has some nasty but not otherwise fatal marks in it (like somebody -- not me -- wiped off dirt with a wet rag), would a very fine abrasive polish be appropriate?



Also, if such paint is over-polished so that the shiny layer is compromised, will a polymer/acrylic sealer like Klasse SG or Zaino provide a lasting gloss, or is all hope lost?
 
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