Chip Repair Problem!

[AustrianOak82]

Hey guys. Having a problem with a touch-up job and wanted to see if anyone had input. I was doing chip repair on a 2010 Toyota 4Runner. I picked up some TU from O`Reilly in Salsa Red and prepped the chips for painting. Here are the steps I took:

1. Applied the paint using a fine detail brush
2. Dried chips using a heat gun on low from about 2 feet away. I did this for 2-3 minutes and checked about every 30 seconds to make sure the paint surface wasn`t hot.
3. I allowed the chips to dry another 15-30 minutes and got ready for wet sanding.
4. I wet sanded the chips using Meguiar`s Unigrit 2500 until level.
5. I then repeated the above steps for the 2nd coat.

When I started sanding the 2nd coat, I noticed the TU was turning very dark gray, almost black. The paint was not tacky when I started sanding and had a hard feel to it. I went ahead and applied another coat over the top and went a little light and smoother this time around. I sanded lightly with 3000 and got the same result. In the end, the photo shows what I was left with. I am getting the car back in about a week for round two and need to figure out what happened here. I posted on AG and some guy suggested maybe during the drying process, the flakes had settled/floated so when I began to sand, I was only blending in the darker flakes with the red tone underneath. I figured I would post on here as well and see if anyone had this issue before and had any feedback. Thanks!

[Accumulator]

AustrianOak82- Welcome to Autopia!

Some sorta-random thoughts about your situation follow:

-I wouldn`t use the heat gun to speed up the drying
-I wouldn`t wetsand between coats of TU paint
-I`d do more (and thinner) coats of TU paint
-I`d be shake shake shaking a metallic TU paint, like...all the time
-I`d quit if/when I noticed the color getting weird
-I`d let the TU paint dry/cure for a while before trying to wetsand it
-I`d verify that the TU paint you`re using (is it single stage?) will respond well to wetsanding (some paints don`t)

I dunno if any of the above will be helpful, but that`s what came to mind.

[edb]

I thought i read a couple of posts on touch-ups a few months ago where the original poster said he would put the touch up paint in then wait a month for the paint to fully cure before wetsanding etc. I believe one of the reasons was to make sure the touch up paint doesn`t come out while wet sanding and compounding. His results looked excellent. I will see if i can`t dig up a link.

[Accumulator]

edb- I`m one of those guys who`ll wait a *long* time...dunno if it`s necessary but that`s generally what I do when using conventional touchup paint. With DRColorChip I don`t wait nearly as long.

[ShaneB]

I wouldn`t sand the paint at all either. Also sanding with anything higher than 600 grit will cause adhesion issues as you don`t give the fresh paint anything to bite on to.

There is a difference between dried paint and cured paint. Paint that is dry yet hasn`t fully cured, can be layered without any additional steps. Cured paint (given a long time to dry, from days to weeks) will need to be sanded to allow the fresh paint to adhere

[AustrianOak82]

I will probably go ahead and pick up a different brand of TU paint. I will sand these down smooth and apply a thin layer over the top and let it dry for a week or two. The chips are pretty much totally filled in, so we will see what happens.

[Accumulator]

I will probably go ahead and pick up a different brand of TU paint. I will sand these down smooth ...

I myself probably wouldn`t do that. If I needed to undo any of the existing touchup I`d do it with something like Langka`s Blob Eliminator. I worry about all that sanding affecting the OE paint for one thing...