[sassy]

Hey Guys
after reading barrys clear test I was wondering if after cutting the clear at 320 or 400 would it not be a bad Idea to sand up to 1000 or 1500 and buff before reclearing to give it a cleaner deeper look..

[baddbob]

No, shoot the next application of clear over the 320 or 400 and you'll be just fine. The reason this grit is suggested is because it cuts flat and fast and the scratched it produces is easily covered with the next application of clear. I sometimes finish to 800 grit but it really isn't necessary. Clearcoat is actually a fairly hard product compared to a primer surfacer for example so the scratches produced by the sandpaper on both will usually be of a different severity-make sense?

[sassy]

Thanks Bob
would it not be usefull to sand the 320 or 400 cut to a shine for better definition when reapplying the next round of clear.What is better, gloss on gloss or gloss on sanded clear

[BarryK]

I think I understand what your asking.

Between coats of clear using 320 - 800 will get rid of what they call urethane peel. Urethane peel is not the same as orange peel and unless a painter is a custom painter would probably never recognize it.
Anything finer is only sanding the roughness off the top or leveling orange peel but not attacking the urethane peel.

Once re-cleared urethane peel can show back up if not adjusting your gun, using a wrong size tip, a cheap gun or applying excess coats of clear in that case it would be advisable to first sand with 400-800 and then start sanding over those grits with finer grits until ready to buff.

[MARTINSR]

Originally Posted by sassy

Thanks Bob
would it not be usefull to sand the 320 or 400 cut to a shine for better definition when reapplying the next round of clear.What is better, gloss on gloss or gloss on sanded clear

What Barry found with his test (correct me if I am wrong Barry) is that cutting the first coats of clear with 320 provided a higher, clearer gloss than the traditional cutting of that clear with 600 or finer BEFORE adding that last "flow coat". This was very valuable information and pretty clear (if you'll pardon the pun).

If sanding with 320 provided a better gloss than sanding with 600 or finer, how could polishing that clear after cutting with the 320 make it any better? I don't see it, as far as I am concerned Barry found that all that is a waste of time.

If you cut with 320 it cuts it FLAT and the following coats of clear EASILY fill those scratches so why polish it?

Brian

[jcclark]

I agree, Brian. At that stage the only reason to polish it might be
to remove dirt or trash in the clear. (??)

[sassy]

Thank you guys for all the exellent advice,first off I didnt understand that sanding 320 was for urethane peel,(I thought orange peel ).I guess what Im trying to say is if you painted 3 panels, 1)strickly gloss over gloss 3 coats no sanding 2)3 coats 320 cut and reclear 3) 3 coats 320 cut sanded to buff stage and beyond and then recleared,which one would be the most glossy by the gloss meter or eye.Also assuming a)average shooter B)very good shooter.
Cant get this one out of my head

[BondoKing]

Originally Posted by jcclark

At that stage the only reason to polish it might be
to remove dirt or trash in the clear. (??)

Are you talking about my paint jobs ole buddy

[MARTINSR]

Sassy, I think you are making this more complicated than it is.

A. Clear two or three coats, cut with 1000, clear two.

B. Clear two or three coats, cut with 320, clear two.

"A" produced a cleaner, sharper gloss of the two.

I think that was all there was to the test, it was that simple. We chatted about it and all agreed that the 320 cut it down FLAT instead of rolling over the "peel".

I don't remember the difference in the discussion about "urethane peel" and "orange peel" but there is a big difference between the two. "Urethane peel" is more of a "ripple", "washboard" effect because the high solids in todays urethane clears. Even a few coats more on a panel next to another previously cleared panel with those few coats less will show it RIGHT NOW. I mean a BIG difference. So if you are going apply more than the two or three (even that third one will add a lot of "ripple") then cutting it down FLAT with 320 will eliminate most if not all of it.

Brian

[colormecrazy]

I'm sorry to butt-in guys, but It's my understanding that clear will not stick to buffed clear, isn't that why we scuff blend panels?

[baddbob]

yup, scuff/sand for adhesion. There wouldn't be much adhesion if sprayed over buffed and cured clear.

[the milkman]

The only time you will sand, and polish a finish prior to more paint is when using Alsa's Mirra Chrome, or the like. This is also meant to be a graphic color, and is for show. If it is on a daily driver, it will not last. You have to have adhesion either chemical (second coat within 12 hours or so, 1 hour for clear), or mechanical (scuffing). If you want to add more clear, or a flow coat, you would sand with anywhere from 600 to 1000, and reclear. 600 will give more adhesion but a slight haze on most dark colors. I've been using 800 grit for years without any problems. If you use 320 or 400 and put clear on top, you will not have the best finish, and on black it will look bad. My guidelines are primer sufacer 400 then seal. 600 wet then base. Clear within 24 hours for chemical adhesion. Last but not least, if you actually drive the car, stay away from more than six coats or clear. Any time you increase the thickness of the job, it will cut down on durability.

[BondoKing]

The test was done, and Barry checked everything with a gloss meter.. The 320 showed the highest gloss enhancement over everything else, and I believe 1000 was used in the test also.. Take it for what its worth, I use 320 all the time.. and I re clear over it on dark colors.. and they look grea.. here is one re cleared over 400, it is a reflection in the panel.. No haze here

[colormecrazy]

Wow!! ...and I thought I was ugly!

Just kidin! Looks great!

[sassy]

Yes I would agree ...that is quite a mirror finish very nice bondo...btw its bin at least a cpl days since the last one