[Cloud9blue]

I am planning to fix some of the rock chips on my front bumper with touch-up paint, wet-sanding, and polishing.

The touch-up paint that BMW supplies comes with a bottle of clear coat as well. Just wondering if you apply that on top of the color base coat. The clear coat seems pointless to me since it might just get mostly sanded away by the time you finish wet-sanding and polishing.

[Cloud9blue]

bump?!

[jopa489]

You bumped a four hour old thread? In this forum?

Someone will come along with knowledge on this, there's a lot of people here with a lot of smarts. Be patient.

[Cloud9blue]

alright, a day has passed. time for another bump!

[Fritzables]

AlpineCloud9

Yea, just paint right over the top but make sure it settles so the paint is level with the rest of the paintwork. If it sits high, it looks piss-poor.

Fritzables.

[Andy M]

Originally Posted by AlpineCloud9

I am planning to fix some of the rock chips on my front bumper with touch-up paint, wet-sanding, and polishing.

The touch-up paint that BMW supplies comes with a bottle of clear coat as well. Just wondering if you apply that on top of the color base coat. The clear coat seems pointless to me since it might just get mostly sanded away by the time you finish wet-sanding and polishing.

Base coat should be as thin as possible such that it just covers the non-painted area and that's it. It's the clear coat "filling" up most of the space. You'll be sanding down the clear coat, not the base coat. Otherwise the paint layer will still be "high" even if it's smooth with the rest of the paint (it'll sit in the layer where it used to be clear coat).

I like to use the base coat touch-up just to hide the exposed area, then put the clear on, wetsand (going from 1000 grit to 1500 to 2000 grit), and then polish with Menzerna Intensive Polish and then Final Polish on a low speed.

I prefer to spray paint the area instead (primer, base, and clear). I'd only use the touch-up for VERY small areas.

[Cloud9blue]

Originally Posted by Andy M

Base coat should be as thin as possible such that it just covers the non-painted area and that's it. It's the clear coat "filling" up most of the space. You'll be sanding down the clear coat, not the base coat. Otherwise the paint layer will still be "high" even if it's smooth with the rest of the paint (it'll sit in the layer where it used to be clear coat).

I like to use the base coat touch-up just to hide the exposed area, then put the clear on, wetsand (going from 1000 grit to 1500 to 2000 grit), and then polish with Menzerna Intensive Polish and then Final Polish on a low speed.

I prefer to spray paint the area instead (primer, base, and clear). I'd only use the touch-up for VERY small areas.

That's the kind of answer I was looking for. Thanks!

[Andy M]

Originally Posted by AlpineCloud9

That's the kind of answer I was looking for. Thanks!

No problem. Some say the largest you should go for touch-up is the size of a pencil eraser but I think that's a bit big still. I would go half that size (maybe the size of the pencil eraser that sits inside on of those lead pencils...)

Forgot to add, another reason you NEED to use clear coat is that you can't polish base coat. You can try but it won't shine as much as the rest of the car making the paint chip even more obvious in the sun. So even if you sand down the base coat, it won't help at all.

Don't use the BMW OEM touch-up paint's brush for the base coat - it's way too big. Use a toothpick instead. Might take you more than one base coat to get it all but it'll ensure that you're keeping it as thin as possible.

[oriolesfan03]

I would use the clear single stage paint is weak, you shouldnt have to wet sand unless yo uhave runs or drips or dirt

[Haywire]

I was told different as far as how much paint to clear goes into the chip, but i guess either way works. Ill just write it down the way it was explained to me. regardless the application is the same.

the paint should be built up layer after layer on the chip youre fixing, the clear should be the last application in the chip and should slightly lift over the ridge of the chipped paint (obviously not flowing over) take into consideration that the clear will also settle into the groove and expand slightly. then go to town with whatever you wanna do.

[John 070]

Originally Posted by Haywire

I was told different as far as how much paint to clear goes into the chip, but i guess either way works. Ill just write it down the way it was explained to me. regardless the application is the same.

the paint should be built up layer after layer on the chip youre fixing, the clear should be the last application in the chip and should slightly lift over the ridge of the chipped paint (obviously not flowing over) take into consideration that the clear will also settle into the groove and expand slightly. then go to town with whatever you wanna do.

I think it's important to have realistic expectations when it comes to touch-ups. I watched a pro do my car. He had brushes that you and I probably would not (small). He built it up, 4 layers. When all is said and done, because we have critical eyes, after all his effort (maybe 35 min. on one chip), the chip is pretty obvious due to having gone down to metal. Paint matches perfectly.

To me, there are two outcomes, either the repair is concave or convex. Either way, it's obvious at some angle. It's just better than having bare metal exposed, and there are certain angles from which someone else wouldn't happen to notice. But to the owner, as I said, totally obvious.

[Andy M]

Well from what I know, all are correct here. You want to keep the layers as thin as possible to avoid having clumps of paint.

Paint brushes that work great for me (if not using a toothpick) is the fine tip brushes from an arts store.

Ok, in a nutshell this is what touch-up process is about: you want to replace the missing paint and clear layer with an equal thickness of both. Going as thin as possible with the touch-up paint gives you the most control and the number of layers depends on how deep the chip/scratch is. Basically the touch-up paint is a filler to build up the thickness. The final thickness of the touch-up color coat should be equal the original thickness of the color coat. Clear goes right over. In my experience though, I find the clear to sit a bit higher and so I like to make sure it's sanded down smooth.

[SLCGoonski]

i just got my touch up paint/clear in the mail.

I assume you clean out the chip will with alcohol first??

I've also heard that a toothpick works well...and that you need to be patient and layer the paint/clear. Don't fill it all at once.

[rotaryboy]

Definitely use the clear. It polishes much better and ultimately gives a nicer match.

[ucdbiendog]

if a chip goes down to the metal, about how many toothpick applied layers of the basecoat do you guys recommend to equal the original base coat? Then use the brush with the brush and wet sand? Thanks
~Ryan

[Kruz]

Just went through this process with the BMW touch up two bottle approach. I should have read this thread in hindsight first but I only had three small chips on my hood and one on my a pillar.

I used the brush and dabbed as much paint off as I could and it still laid down a bulge of paint. It's not perfect and the paint seems darker but overall only I notice it and Id rather look at that than 4 tiny rust spots.

I dont have the balls or patience to wet sand.

[therealm3]

Originally Posted by Andy M

Well from what I know, all are correct here. You want to keep the layers as thin as possible to avoid having clumps of paint.

Paint brushes that work great for me (if not using a toothpick) is the fine tip brushes from an arts store.

Ok, in a nutshell this is what touch-up process is about: you want to replace the missing paint and clear layer with an equal thickness of both. Going as thin as possible with the touch-up paint gives you the most control and the number of layers depends on how deep the chip/scratch is. Basically the touch-up paint is a filler to build up the thickness. The final thickness of the touch-up color coat should be equal the original thickness of the color coat. Clear goes right over. In my experience though, I find the clear to sit a bit higher and so I like to make sure it's sanded down smooth.

You seem pretty knowledgeable on this process so I'll ask what you recommend for a scratch that is down to the metal on a door. Same process? I'd imagine gravity will work against me and the paint will dry thicker and gather on the lower side of the scratch? Or will the surface tension keep it relatively even?

[Andy M]

Originally Posted by therealm3

You seem pretty knowledgeable on this process so I'll ask what you recommend for a scratch that is down to the metal on a door. Same process? I'd imagine gravity will work against me and the paint will dry thicker and gather on the lower side of the scratch? Or will the surface tension keep it relatively even?

I had a really deep one so I ended up sanding the area around it, using Bondo Glazing and Spot Putty, applied it using a rubber squeegie (I used the rubber applicator from my Invisible Shield for my iPhone), sanded it down and then repainted it using aerosols. See this thread: http://www.e90post.com/forums/showthread.php?t=271087

Otherwise if you're not using putty, use the touchup base coat and a toothpick. You'll need lots of patience because you have to build the layer back up. If it's thin, gravity shouldn't be a problem since the surface tension of the paint is stronger than gravity. Then you have to do the same thing for the clear coat.

As for wetsanding, it's really not that big of an issue once you start getting good at polishing out scratches. In fact wetsanding deeper scratches is a better idea than going straight to the polish as polishing a single area for too long can heat it up and burn through the paint.

[therealm3]

Originally Posted by Andy M

I had a really deep one so I ended up sanding the area around it, using Bondo Glazing and Spot Putty, applied it using a rubber squeegie (I used the rubber applicator from my Invisible Shield for my iPhone), sanded it down and then repainted it using aerosols. See this thread: http://www.e90post.com/forums/showthread.php?t=271087

Otherwise if you're not using putty, use the touchup base coat and a toothpick. You'll need lots of patience because you have to build the layer back up. If it's thin, gravity shouldn't be a problem since the surface tension of the paint is stronger than gravity. Then you have to do the same thing for the clear coat.

As for wetsanding, it's really not that big of an issue once you start getting good at polishing out scratches. In fact wetsanding deeper scratches is a better idea than going straight to the polish as polishing a single area for too long can heat it up and burn through the paint.

Thanks! I'll give it a shot. can't look worse than it does now.

[darkphantom]

ok, i'll do this soon as well....got a good amount of mini rock chips that need to be filled in via toothpick touch up paint