Marc3.4V6

iTrader: (1)

I'm a professional painter and I just started having this problem with Sikkens clear. I've started noticing, especially on black cars, that I can see where I sanded with 1000 grit and marks from my grey scotchbrite on parts of the panel where I have no color, just clear. Never ever had this problem before with any paint manufacturer. I used to do everything wet and wash everything before paint, but since we switched from Spies Hecker to Sikkens and got bought by another shop and have a lot more work, I do most everything dry. There's no time to meet their expectation of how many cars we paint per day for cars to dry off most of the time. The paint rep for Sikkens liked that I washed cars before paint, but said that most of their shops stopped doing that to save time.

What he told me to do was to wipe the car down with solvent based cleaner prior to sanding, then hit it with 1000 grit dry on the DA with an interface pad and then get corners by hand and with grey scotch pad, all dry. After that washing was up to me. So I didn't see any problems until the past few weeks. I don't think this is new because I also buffed several cars that I or the head painter sprayed and noticed none of the haze from my blend prep sand scratches I'm seeing now. Service has been lackluster from the paint rep as he does all the shops in the state. This is why I'm posting here, I'm perplexed by this issue. Today I did a black fender dry and forgot that I was going to stop doing that on black so I hit it with 1000 wet after I did everything dry and it still didn't cover the scratches. Then I noticed it on a dark red car on most of the bumper and some of the quarter. The paint rep did say over the phone to try doing everything wet plus use liquid sanding paste with the scotch pad to get all contaminants off the clear, but I don't see how it can be different, especially If it's being wiped down before, and of course thoroughly a second time when in the paint booth before I spray.

If you're having a hard time picturing what I'm saying, it looks like it does when you're in the middle of color sanding and buffing but there are still scratches that need to be buffed out. Like when it looks shiny, but you still need more time with the buffer because of faint sand scratches before you move on to polish only it is fresh out of the booth and has not been touched. Any ideas from other pros?

ur-n-8

Do you use a "wet bed" or adhesion promoter on the blend panel before applying the color?

Marc3.4V6

iTrader: (1)

This paint system doesn't have that, the Spies Hecker system we used before did, it was a thin milky white coating that dried clear that we put on the the blended parts of the panel(s). The Sikkens does not, do you think that would have helped? We did have one painter come in and do that with a "correction binder" and use it that way, but I don't think that's something that Sikkens instructs you to do. That binder is a component in many of the colors so I don't think it's correct to use it that way in this system but it's worth asking if this problem doesn't have an easy solution.

1FastBrick

iTrader: (16)

IF I remember correctly, I believe in the past Sikkens had us over reduce the clear coat to use as a blending agent. It was applied before spraying the color and clear coating.

Black99TransAm

iTrader: (16)

I would honestly say it would be a issue with sanding technique. I have found that gummed up scotchbrite will put deep scratches in it. I always use a blow gun and constantly blow the scotch brite out and blow the surface off constantly. that has been my issue in the past. I spray ppg envirobase and ppg deltron clears and the envirobase has to have a very fine scratch or it will show sanding scratches.

on another note if your having issues couldn't you talk to your paint rep or jobber and get them to give you some ideas