Well the Thread over on 101 got me too looking close not real close but close enough to my current project and after looking it over I decided to give my Roof one more coat of Primmer and re sand it out.

But I was wondering were I might have went wrong And if it was a real problem to begin with.


Here's what I had done
First we striped the whole car down to bare metal then did a tiny bit of mud work followed by a coat of SPI Epoxy let that dry for a few days then Put on a couple coats of SPI regular Primer Blocked out initially with 180 dry followed by 400 dry Then another coat of Primer blocked again by 400 dry just to open it up quikly followed by 500 Wet.

Well after looking it over very closly I could see some Heavy scratch in it on the roof ONLY looked like 180 scratch this is after that thread came up over on 101 and well I didnt like the idea of seeing all that or even the possibility of seeing it through my clear so we tried to wet sand it more but to no avail it wouldnt sand out so we cleaned it good and applied another coat of Primmer scuffed it 400 dry followed by 500 wet again this time its great and I am sure after I wash it today it will be ready for Base and clear.

So were did I mess up the sides were Golden done the same way initially and they are perfect and ready for paint but the roof had all the scratch.

Hmmm
Did I mess up with my blocking starting with the 180 by not going to like 320 before 400? Thats about all i can figure

OR
Should I have left it alone and just shot the thing with my Base and Clear and called it good as the base coat being Black would have covered it up just fine and my clear would have been two coats followed by a flow coat and nothing would have shown?

Always follow the 100 grit rule. Don't jump more than 100 grits at a time. You can get by with 200 grit jumps after P600.

It would be hard to get out P180 scratches with P400. Also go buy some 3M guide coat. It will help you with seeing any remaining sand scratches you haven't removed.

I know the work i do is different but i deal alot with sanding scratches since i work with fiberglass and I am mainly shaping things, however i use red spot putty which sands so easy. I spread it with my finger and it fills the scratch and then primer over it. Never fails. No hardener, drives in 25 minutes

I think it would take you forever to remove the 180 scratches with 400, I'd try to avoid touching primer with anything coarser then 280 and like ryan said upgrit in smaller steps. Being black you could very well bury the scratches in clear if you wanted to but if you did it in one application it would likely dieback like crazy. I think your best to let it dry, sand down the rood with some 600 without breaking through the clear (just remove the scratches) and re-clear the panel with another coat or two.

You could of also just hammered on 4 coat of clear, sand it down and polish too... I don't know if I'd recommend that method, I'm sure there are risks with putting on that much clear in one sitting.

Hey Jim
I guess I didnt explain well enough The car is still in Primer.

I'm wondering more IF it would have been a problem?

Like I said I put another coat of primmer on it last night and blocked it again with 400 and 500 looks good now I'm planning on shooting my Base coat today IF every thing goes right today.

Ryan
Yep I was thinking that I over did it in my Jump in grits too.

Nexson
I would stay away from those single stage type filler's except maybe to use it as Run remover!
Like Jimmo showed in one of his posts thats the best use for it I have ever seen!
I have had many bad spots show up under my base from that stuff when I first started now I only use a real two part fillers for even the smallest of any filling even pin holes.

My biggest concern would be sinking, as the urethane primer cure's I'd bet the 180 scratches will show.

What did you sand your filler work with before you layed down the Epoxy?

how did you remove the paint to get it to bare metel?
Are the scratches that are showing only where there is filler?

Alex
180
80 grit
No
Actually were the scratches were was on the roof only I fixed it with another coat of 2k primmer and sanded it out with 400 and 500 wet.

Last night after washing it all down with soap and water letting it dry out then wiped it all down with W/G remover and shot Base Got some trash from not useing Tack rag after W/G remover. Very upset with myself right now


Bondo Mud work wasn't a whole lot of it But I did do some
I put some slick sand over the Epoxy I put on too.

I believe it's best to use 80 to strip with but then go over everything with say 180 on a DA before proceeding with epoxy.
Some guys will go straight over the 80 with epoxy but the possibility of shrinkage causing the 80 scratches to show is a concern.

180 to 400 is a big jump. and really 400 is too fine to reprime over. 180 to 220 for priming with some 320 around the edges.