RacerX1166

Hello all

The PO of my 89 Baltic blue coupe did some touch up work on the hood that borders on criminal, leaving a few noticable blobs of paint behind (and still not filliing the chip that he was attempting to repair). I'd like to get rid of the blobs and fix the chips correctly. I previously owned a garage queen black BMW 540 with a fairly low Breyton front spoiler so I consider myself quite handy at doing touch up work. My usual method utilizes touch up paint applied by hand and Langka, which has provided great results over the years.

However, since I'm working with chips that have been touched up previously and paint that has likely cured to where the Langka will not remove it, I want to arm myself for the next level of battle. Would this, indeed, be wet sanding? If so, based upon what I've read, I need to grab some 3000 grit paper (I have 1500 now) to get started. What else do I need to know before proceeding?

Another question is whether I have the right materials to complete the task? I have the standard PC orbital, along with pads all the color of the rainbow. My current stable of polishes are Menzerna Intensive and Final polish (along with a bunch of others but those are the ones I've used on the car so far). With an orange or yellow pad, will the Intensive be enough to bring the shine back to the paint prior to final polishing?

Also, what tricks do I need to know about wet sanding? I've seen references to soaking the paper in water overnight. Is this something that needs to be done?

Thanks in advance for your guidance.

Detailed Image

RacerX1166 - Sounds like you have a good idea on taking care of those touch up blobs. I'd start with a fine grit sand paper, such as 2000 - 3000 and even out the blobs. Since the paint is already cured, it should be somewhat easy to level properly. It can be helpful to soak the paper overnight in water, I do this when I wet sand. It helps soften the paper a bit and makes it easier to work with. Since you're finishing with a high grit sand paper, you should be fine with the PC, 4" pads and Menzerna polish combo. Take your time, it's always better to make more light passes than it is to make less passes with more force.

Good luck and keep us posted on how things turn out for you.

George

RacerX1166

George, thank very much for the input. It was exactly what I needed for piece of mind.

My confidence level was not that high after my last (and first) foray into wet sanding. In retrospect, I didn't do enough research and went right to 1500 grit (it felt smooth to my hand). Plus it was a side mirror so not really conducive to using the buffer afterward. Nothing ruined but I could never quite get the shine back.

I sourced some 2k and 3k paper yesterday on the way home. Since there was additional chip damage to repair, and I was pretty much determined to attempt wet sanding, I elected to touch up the whole car. At this point, I'm going to stick to wet sanding the hood only (maybe the front bumper) and utilize Langka for everything else, since the 'everything else' touch up paint will be fresh. No point taking any more clear coat off the car than necessary since it still is original paint.

Color blobs went on last night and clear will be done tonight. I'll probably do the Langka tomorrow night and hold on the wet sanding until later in the week, when I can follow up with a wash and appropriate polish, wax, primping.

While the car looks really great overall, I believe the whole hood will benefit from wet sanding with a fine grit since it has the inevitable fine scratches that accumulate over the course of 20 years but won't come out with a PC. I have to resist the temptation to wet sand too much of the car, since it likely doesn't need it. There are some mild defects on the roof (water spots, etc.) that I was considering wet sanding but I think I'm going to try a more aggressive pad with my PC and Intensive polish before taking that route.

I have definitely learned the 'lighter is better' technique from using the Langka. You can rub like mad until the blob starts to erode but, at that point, you need to back off and let it do its job. Otherwise, it will work harder than you wish, the result being the same chip you started with.

If I think of it, and don't destroy my paint, I'll take some closeup before and after pics to share.

Marine Blue

Langka has worked very well for me over the years. I'm going to touch up a few new spots this year and revisit others to blend them further.

Have you considered using a rotary on your hood instead of wet sanding? Unless of course the scratches are few and far between, then wetsanding would be a good approach.

Detailed Image

Agreed, if you have access to a more powerful buffer, such as a Flex XC3401VRG or a rotary buffer as Marine Blue mentioned, I'd try that before wet sanding the entire hood. It sounds like your describing RIDS (random isolated deeper scratches) in your paint. Depending on how deep they are, chances are you can remove them without resorting to wet sanding. The PC does have it's limitations on how fast you can cut through the clear coat, wet sanding would certainly accelerate the process. Before you wet sand the entire hood, I'd recommend spot treating a small area just to make sure the PC can clean up the wet sanding marks the way you want them to. Also, make sure you have the proper lighting to make sure you're removing the RIDS, I typically use dual 500w halogen lights or good florescent lighting or a sun gun.

Good luck, be sure to keep us posted on how things turn out.

George

RacerX1166

I was too scared to damage my paint so I never purchased a rotary buffer. Admittedly, I didn't use my PC as aggressively as I possibly could on the last go 'round (compound with aggressive pad) so I'll likely try that avenue with wet sanding reserved for the older chips and Langka for the newer repairs.

I do have good lighting (dual halogen work lights) and need to rely on it to verify my paint condition throughout the process.

More to follow as I get closer to taking paper to paint.

RacerX1166

Argh! This paint is even softer than BMW paint! I just chewed through the clear coat in two spots using Langka. Hoping I can do some repair and make it less noticeable. Not in conspicuous spots fortunately.

Wow, I bought my touchup paint from Paintscratch and their clear is like nails. I've been Langka-ing for two nights so far.

Just have to keep reminding myself how great the car will look when it's done....

Marine Blue

I've had very bad luck applying clearcoat when touching up paint chips for the exact same reason you mention. I've found especially with metallic paints that the best results are achieved using just the touch up paint. Use one or two light layers, wait an hour, langka, wait a day, add more touch up paint, wait an hour, langka wait a day and then decide if you need to repeat. Avoiding clear will also help to blend the metallic since the flakes tend to settle at the bottom of a chip. Touch up paint (factory) is also soft and you can usually successfully langka even after a day.

RacerX1166

In all honesty, that's how I used to perform the repair but I figured I would 'do it right' with the P-car and use the clear.

Off to Home Depot to replace the hose that 'disappeared' when I moved in, then back for wet sanding round 1.

I'm a bit torn on what i want to do on the clear that's been removed. I applied color to it but am still debating how to blend it. Both spots are on edges of panels so I don't want to make the situation worse. I'm thinking Langka to start then wet sand to finish. That's right now; I may change my mind 12 times before I start.

Marine Blue

If I'm not mistaken, touch up paint from the factory is designed so it can be used without clearcoat.

I also discovered on a previous car (MB) that Langka will remove the factory clear if your not careful. Luckily I discovered it before it was too late.

RacerX1166

Well, it's done and I can report mixed results. Overall, the car looks great but there are a few downsides.

With regard to the offending major stone chip, the paint is now flush with the surrounding paint but I came away with the same issue that Marine noted, that of the color settling to the bottom of a sea of clear. I'd give the result there a B+.

The other issues I encountered were two spots where I burned through the clearcoat, attempting to Langka down the touch up clear. This is the first time I ran into a. Langka burning through clear and b. touch up clear being so tough.

As a result, there are a few spots (i.e. mirrors) where there are still a few blobs of clear touchup due to my fear of burning through yet another piece of factory clearcoat. I may wet sand those with a smaller block and see how it turns out.

A few minor scratches remain which may come out with some wet sanding or a higher power buffer.

Over the winter, the front bumper will require a respray due to an burning through the clear as well as a few major chips which would not cooperate. I burned through the clear on the edge of the hood but repaired it to where it's not noticeable.

Lessons learned:
-I can wet sand and obtain great results. And the shine comes back with a PC, a yellow pad, and Menzerna Intensive Polish.
-In the future, I'll definitely stick to using the color coat only for repair.
-I need a higher powered buffer - there were a few scratches that I'm sure would have come out with a beefier unit. Now that I'm used to the PC and what it will do, I feel comfortable stepping up. BTW, the PC with a yellow pad and Intensive didn't even produce a compounding haze.
- Langka will burn through paint (despite my previous experience) especially at the edges of body panels
-No matter how long you spend touching things up and attacking scratches, there are always a few you missed and find during the later stages of paintwork (glazing, waxing). Deal with it....

I know...I still owe some pics. I haven't taken any yet since I spent the weekend in a constant state of panic due to finding more things to do to the paint. Will share them later this week.

Marine Blue

This feedback will definitely help others.

Your right about finding more chips, its an ongoing battle!