clearcoat, wetsanding, then clear it again

[68RRFlyer]

Hey Gang,

Well got the runs on the sealer all wetsanded out, reapplied some more sealer and the car is now jamb painted.  Looking pretty good and tomorrow I'll spray the rest of the car.  Should have the clear on shortly and have a question for the guys that do this regularly.  I've read and heard several techniques on sanding the clear.  The one I'm interested in involves spraying two/three coats of clear, blocking it down with 1500/2000, then spraying a final coat of clear on top of that for an ultra smooth finish.  I've never tried that.  I've just sprayed three/four coats then blocked and buffed it out afterwards.  The first scenario seems like it may result in a better final product.  Any thoughts?  I'd be worried about sanding scratches imbeded into the underlaying clear that won't be able to be buffed out.  But I  guess with more clear being sprayed on, then it should cover that up.  What are you guys doing?  

Cheers    

[Silver R/T]

Nothing wrong with putting more clear on it after you've sanded it. You can actually apply clear over single stage paints and buff them out and it will look just as good as bc/cc paint job.

[BBKNARF]

You can do either way, I rather clear it then sand and polish it, its quicker rather then clear it, sand it, wipe it clean then clear it again, no thanks.
Just give it 3 good coats of clear I usally let it dry for 24 hours then sand and polish, remember when sanding keep your paper wet at all times carefull around edges, just do small areas first just to get use to it.

[TylerCharger69]

I agree if you apply at least three coats of clear...you should have plenty of wet sanding thickness.....and use your whole hand...not the fingers...that'll dig "holes" in it if you do. 

[elitecustombody]

depending on the clear mixing ratio,if it's watered down 4:1, I'd shoot 4 coats, if it's 2:1 mix, I'd do 3 coats, wait a good month and then start with 1200 wrapped around a hard flat block , waiting 24 hours is way too soon and you'll end up with die-back ,let it cure fully before colorsanding and buffing

[Silver R/T]

depending on the clear mixing ratio,if it's watered down 4:1, I'd shoot 4 coats, if it's 2:1 mix, I'd do 3 coats, wait a good month and then start with 1200 wrapped around a hard flat block , waiting 24 hours is way too soon and you'll end up with die-back ,let it cure fully before colorsanding and buffing

x2 it will be still soft inside, even though on outside it will look and feel all dry. Also stay away from cheap clear coats. Use rubber squeegee to squeegee off sanding residue as you're wetsanding it. You will be able to tell how much more you need to sand. Low spots will still be glossy. You want it all dull/uniform before moving onto finer grit. Like Elitecustom said, start with 1200, progress onto 1500 afterwards, then 2000 and you can finish it off with 4000 and it will be already pretty glossy after 4000.

[68RRFlyer]

Wow, wait a month? I've always been told it's maybe a day or so, but not later since it gets too hard. The ratio is 2:1 and I had planned on three coats.  First one being a tack coat, not so thick.  Then the subsequent last two thicker and heavier.  Wet sand everything then apply one last coat.  I was just asking about that technique since I never used that before.  It's always been 3 coats then cut and buff.  I'd never sprayed on clear after the final sanding.  So maybe this time I'll wait the month to wet sand.  The problem is I'm losing my paint booth next month so if I'm going to sand/clear the car again I'll have to do it pretty shortly.  I think I'll stick to the 3 coats then cut/polish method I'm used to.  Always learning, that's what makes it fun!  Headed out this afternoon when it warms up a little to shoot the rest of the car.   

Cheers   

[speedfreak68]

It will get harder but if you wait longer the paint will be done gassing out and you will get a better finish...at least that what i was told. 

[MichaelRW]

FWIW, here's the instructions the DuPont rep gave me when I painted my Charger. They are, of course, for the Chroma system.


1st coat of base use a 75 % reduction of basemaker instead of the 1 to 1 (Chroma to basemaker)

then two more coats of base at 1 to 1

2 full coats of clear

Bake

Cool for 2 hours

wet sand w/ 1000

then 1 more nice wet coat of clear

[TylerCharger69]

I dunno...ive wet sanded and buffed clear coat 5 hours after shooting with no issues....Usually the delcotron products....i dont know how other brands would respond to that though

[elitecustombody]

Wow, wait a month? I've always been told it's maybe a day or so, but not later since it gets too hard. The ratio is 2:1 and I had planned on three coats.  First one being a tack coat, not so thick.  Then the subsequent last two thicker and heavier.  Wet sand everything then apply one last coat.  I was just asking about that technique since I never used that before.  It's always been 3 coats then cut and buff.  I'd never sprayed on clear after the final sanding.  So maybe this time I'll wait the month to wet sand.  The problem is I'm losing my paint booth next month so if I'm going to sand/clear the car again I'll have to do it pretty shortly.  I think I'll stick to the 3 coats then cut/polish method I'm used to.  Always learning, that's what makes it fun!  Headed out this afternoon when it warms up a little to shoot the rest of the car.   

Cheers   

the longer you wait, the better the gloss will be,it will give enough time for solvents to escape,

I used to sand and polish next day and have customer bring the car back in a month,if they need the car , I then go over with 2000,3000 and finish polishing to a mirror gloss,     

[hemi-hampton]

I let my 69 Mustang sit 6 months after Painting before I rubbed it. Yeah, Crazy, BUT, It had the best shine ever & never dulled out or dieback or shrunk like you get with a next day rub. Only thing you need to know is which clears get rock hard after a week & which ones will stay soft. A Polyurethane (like Imron) will be impossible to sand a week later. I''d wait at least a week.  LEON.

[69DodgeCharger]

Nothing wrong with putting more clear on it after you've sanded it. You can actually apply clear over single stage paints and buff them out and it will look just as good as bc/cc paint job.

That's what I'm doing. If I had to do it over again though I would just go base clear to start with. I wanted the base/clear look with the cheap single stage enamel price....Not happening. So now I have more work into it and just as much money probably as if I'd just done base/clear to satrt with. Choosing a metallic paint didn't help my cause any either I'm guessing.

[68RRFlyer]

Hmm, OK.  Thanks guys.  What to do, what to do!   I don't want to experiment with a new procedure on this car, but I wasn't happy with the way my Road Runner blushed after a few weeks after I cut and buffed it.  That's why I was thinking about the sanding in between the last coat.  The more I look at that paint job, the more I realize it was : A) not sanding down the car flat enough prior to color, and B) not waiting long enough for the clear to cure.   The base layed down great on the 68, nice and smooth, everything's flat.  Plus, I sanded down that thing to 600 before applying the color so I know it's flat.  I guess I'll lay down two coats and see how we look then decide what I want to do.  I know that I'll defenitely wait a few weeks before the final cut/buff based on what you guys are saying.   

Cheers     

[69DodgeCharger]

Does a guy really have to go all the way to 600 grit while blocking? I have been doing my "rough" blocking/final body work with 320 dry sanding and was going to wet sand the sealer with 400 grit? But I'm just looking for daily driver results. As far as painting the clear over single stage enamel me and my buddy have both done it now with no adverse results. His paint is almost a  year old and sat outside all last winter. mine is 2-3 weeks old.  But here's the thing. In both cases we sprayed the clear on right over the last color coat as soon as it flashed. What has been working best is 2-3 color coats and 2-3 coats of clear depending on how it's looking. Recommended?...Probably not. Pain in the ass?...Yep Will there be "reaction/shrinkage" issues later?...I hope not.  Most people seem to like it, although as mentioned before you have an "overly" glossy look to your old car.

[bill440rt]

I always like to wait until the paint cures before sanding & buffing. I think I waited about 3 months before sanding/buffing my car. I actually find it easier once the clear is cured. If it's too soft you'll actually put buffing marks in rather than polish them out. Plus, it will die back again & you'll just have to start the process all over again. And, this time the clear will now be cured, so why rush it?
I never saw the point of clearing, then sanding & re-clearing again. I've seen poor adhesion issues where the next layer of clear peels off in sheets. Also, if you do this, giving it just one more coat of clear is not enough if you plan to sand & rub. You're sure to sand through to the underlying layer of clear, and then you'll see where you sanded through. 4 initial coats of any hi-solids clear, with proper drying time between coats, should be plenty of mil thickness if you're planning on sanding/rubbing.
I like to start with 1000 for an initial cut, and gradually work my way up with a final sanding of 3000-4000 grit.

[69DodgeCharger]

Bill what kind of times do  you like between your coats of clear usually? garage is usually in the 70's during painting, although due to my poor facilities I have to open the doors to air it out between each coat. I am using the cheaper type Auto Value Production clear

[bill440rt]

Bill what kind of times do  you like between your coats of clear usually? garage is usually in the 70's during painting, although due to my poor facilities I have to open the doors to air it out between each coat. I am using the cheaper type Auto Value Production clear

I really don't have any experience with that clear, so I would advise you to read up on their tech sheets if you have access to them.
Usually, a flash time of about 10-15 minutes is a general rule. Maybe up to 20 minutes depending on temperature and the speed of the reducer your using. A Charger is a pretty big car, so by the time I start clearing at one end of the car & work my way around, leave the booth, mix some more clear, refill the gun etc, it's just about ready for the next coat.

[69DodgeCharger]

Bill what kind of times do  you like between your coats of clear usually? garage is usually in the 70's during painting, although due to my poor facilities I have to open the doors to air it out between each coat. I am using the cheaper type Auto Value Production clear

I really don't have any experience with that clear, so I would advise you to read up on their tech sheets if you have access to them.
Usually, a flash time of about 10-15 minutes is a general rule. Maybe up to 20 minutes depending on temperature and the speed of the reducer your using. A Charger is a pretty big car, so by the time I start clearing at one end of the car & work my way around, leave the booth, mix some more clear, refill the gun etc, it's just about ready for the next coat.

Ok that is about what I was expecting and my general experience with it so far.

[elitecustombody]

Does a guy really have to go all the way to 600 grit while blocking? I have been doing my "rough" blocking/final body work with 320 dry sanding and was going to wet sand the sealer with 400 grit? But I'm just looking for daily driver results. As far as painting the clear over single stage enamel me and my buddy have both done it now with no adverse results. His paint is almost a  year old and sat outside all last winter. mine is 2-3 weeks old.  But here's the thing. In both cases we sprayed the clear on right over the last color coat as soon as it flashed. What has been working best is 2-3 color coats and 2-3 coats of clear depending on how it's looking. Recommended?...Probably not. Pain in the ass?...Yep Will there be "reaction/shrinkage" issues later?...I hope not.  Most people seem to like it, although as mentioned before you have an "overly" glossy look to your old car.

for driver,320/400 is fine.

I could never understand people spraying clear over single stage enamel, why not use basecoat? by the time you buy hardener,there is not much differance cost-wise,but main downside using clear over single stage enamel is unnecessary build-up ,which would count as two base/clear paint jobs, on top of it all,the metallics can get all weird and frizzy if not enough flash time was given and when it's all said and done,you may have alot more shrinking,finish that is more susceptible to chipping and peeling