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View Full Version : Fixing rusted paint chip A-pillar, advice needed



nl318
05-20-2014, 03:39 AM
Hi everyone,

I'm working on a paint chip that turned into a small rust bubble on my a-pillar (bmw 3 series).

My original plan was to remove the rust with a fiberglass pen, and fill it with some touch up paint. However, the pen didn't cut it and I had to use a dremel, followed by epoxy primer to cover the bare metal.

I'm not certain how to proceed now.

Here I've applied epoxy primer.


http://i62.tinypic.com/sytpjp.jpg
http://i62.tinypic.com/2d79fm1.jpg

Things I currently have:

original bmw touch up paint
touch up paint mixed by a bodyshop (waterbased)
original bmw color and clearcoat rattlecans
1500/2000/2500/3000 meguiars sanding paper
DA buffer with microfiber pads

I know respray would be the best option, but for now I'd like to try myself and make it as little noticeable as possible.

How should I proceed? Wetsand the primer, and still try with touch up? Or roughen up some more and spray a bigger area?

Mike Phillips
05-20-2014, 06:07 AM
The picture show primer on the surrounding a-pillar, to me that looks like it's going to be a problem as you're building on top of good paint.

Can you take some lacquer thinner and gently remove the epoxy primer off the good paint and leave the primer only in the chipped area?

I think that's what I would do because if you don't, you're going to have to add touch up paint onto the primered good paint and this will create a high area on the A-pillar.

Does that make sense?


:)

Turboclam
05-20-2014, 06:24 AM
I'd test each paint you have and choose the best color and metallic match. Test it on top if the primer because the primer will affect the outcome of the color.

When you find a match then I'd fill a little at a time. Paint shrinks quite a bit after it dries and hardens. I would also clean the primer off closer to the damaged area so the bad spot doesn't look so big.

The paint that's mixed from the body shop will probably require a top coat of clear as will some of the factory touch-up paint.

It will never be perfect and usually less is more when filling chips. From this point it really a camouflage game. The paint will look different in and out of the sun so pick a happy medium.

Hope this helps.

Michael

nl318
05-20-2014, 03:25 PM
Thanks a lot for your responses!

I can remove some of the primer, I didn't remove it earlier that precisely because I presumed my best option was to wetsand/scuff a larger area and maybe level with filler/bondo and then spray a color and clear. I'm really doubting between this and using layers of touch up paint (from a stick).

But you both would suggest filling it with touch up instead of spraying? Thanks again.

808_detail_nut
05-20-2014, 03:45 PM
I would like to see some after shots, I got a similar situation on my hands and don't know how to go about it. Posted a thread a week or so ago but got no help.

27717


It's about the size of a fingernail and did not break through the primer. How should I approach this?

Sent from my SCH-I545 using AG Online

nl318
05-21-2014, 08:34 AM
I was able to remove the epoxy primer with thinner, still a little bit overlapping the paint but it was as close as I could go without risking to remove the primer too much. I´ll remove some more primer right before painting.

http://i57.tinypic.com/11v00bd.jpg

Mike Phillips
05-21-2014, 09:30 AM
I would like to see some after shots, I got a similar situation on my hands and don't know how to go about it. Posted a thread a week or so ago but got no help.

27717


It's about the size of a fingernail and did not break through the primer. How should I approach this?

Sent from my SCH-I545 using AG Online


Took me about 20 seconds to upload your picture into the AG gallery so everyone can see it....

http://www.autogeekonline.net/gallery/data/500/Paint_Problem.jpg



Most people, (not say you), but the expectation most people have when doing repairs like this is they expect when they are done that there will be no visible signs there was ever a problem. These are high expectations.

Looks like some type of liquid landed on the paint and dissolved it enough to separate the clear and the color layers from the primer.

That's going to take time, skill and patience to fix. You're going to have to start by removing any damaged and lifting paint. Then you can opt to continue trying to do surgery on the area or simply apply some touch-up paint and call it good.


:)

Mike Phillips
05-21-2014, 09:34 AM
I was able to remove the epoxy primer with thinner, still a little bit overlapping the paint but it was as close as I could go without risking to remove the primer too much. IŽll remove some more primer right before painting.




Like Turboclam said, the paint is going to shrink back.

Here's what I do... go to a place like Hobby Lobby and purchase a fine tipped artist paint brush and a small bottle of paint thinner to clean the brush tip.

Next, using the fine tipped paint brush, carefully apply your touch up paint... sparingly. Cover the area and stop and let the paint dry for a few hours. Maybe even put a small lamp next to just to keep the area warmed.

Then apply a second coat, again a thin coat. Let this dry for a day.

At this point, if it looks okay maybe just stop and move on. If there's still a depression, then add a little more paint.

The goal is to fill the area to protect it and make it less visible. What you're trying to avoid is going from a chipped out area to a blob.

Most people end up with a blob. The old... if a little is good... more must be better....


:)

nl318
05-21-2014, 03:10 PM
Thanks, really appreciate the advice! I think I will try this method and see how it turns out. I plan to wetsand the blob to make it level with the rest.

I'm only a little worried the spot might be a bit too big and be fairly noticeable. If it would be, then I guess I will have to fill the gap with filler/bondo and spray a larger area with rattlecans.

Calendyr
05-21-2014, 08:22 PM
Personally I would stay away from touch up paint. It does a terrible job. If you are willing to put the time and learn, your best bet would be to remove the rust using a grinder or very rough sandpaper (36-40 grit), use a little bit of body filler to make the surface flush, prime, paint using color coded paint for your car, then clear coat it.

When you blend the repaint, it's almost impossible to spot once color sanded and polished.

Everything can be done with spray cans, especially for something that small. A lot more work but it will last and it will look good. You are looking at about 100$ in products to do the repair... well that's here in Canada... probably less where you are.

Either way, good luck.

808_detail_nut
06-05-2014, 07:25 PM
Took me about 20 seconds to upload your picture into the AG gallery so everyone can see it....

http://www.autogeekonline.net/gallery/data/500/Paint_Problem.jpg



Most people, (not say you), but the expectation most people have when doing repairs like this is they expect when they are done that there will be no visible signs there was ever a problem. These are high expectations.

Looks like some type of liquid landed on the paint and dissolved it enough to separate the clear and the color layers from the primer.

That's going to take time, skill and patience to fix. You're going to have to start by removing any damaged and lifting paint. Then you can opt to continue trying to do surgery on the area or simply apply some touch-up paint and call it good.


:)

Thanks mike, I'm not looking for a like new finish. I just want it hidden because it really stands out. Especially when it's clean. I'm still trying to figure out what got on it to do that. Anyway, what touch up do you recommend? I have no experience with that.

Sent from my SCH-I545 using AG Online

allenk4
06-06-2014, 02:37 PM
Personally I would stay away from touch up paint. It does a terrible job. If you are willing to put the time and learn, your best bet would be to remove the rust using a grinder or very rough sandpaper (36-40 grit), use a little bit of body filler to make the surface flush, prime, paint using color coded paint for your car, then clear coat it.

When you blend the repaint, it's almost impossible to spot once color sanded and polished.

Everything can be done with spray cans, especially for something that small. A lot more work but it will last and it will look good. You are looking at about 100$ in products to do the repair... well that's here in Canada... probably less where you are.

Either way, good luck.

Seems like a lot for a chip that is on a door edge and is the size of the tip of a car key.

If you are going to spend $100 on supplies....just take it to a specialist that does touch-up.


That primer is going to be a problem if you decide to proceed by yourself.


Looking forward to the during and after pictures

Good Luck