Wetsanding and Compounding issues

[airjames]

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

[Detailing NY]

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

[Preachers Sheets]

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.

[CRXSi90]

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.

[admac]

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.

[Deanski]

Here is the article on proper wetsanding:



Wetsanding article (http://www.goodspeedmotoring.com/?page=color_sanding)



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

[F 355]

Dido...



In fact they now have 3000 grit...but I would use nothing less than 2000...with alcohol wipe in between...

[MichaelM]

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,

[jr weeks]

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.

[Preachers Sheets]

Good to know, so what your saying is stay away from abrasives when it comes to single stage paint.

[jr weeks]

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.

[Preachers Sheets]

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.

[Detailing NY]

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.

[BoNgBlAzE]

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.

[Gonzo]

See here, wet/dry sandpaper to 12000 grit (NOT a typo)



http://www.sisweb.com/micromesh/mmr_sheets.htm