In another thread someone mentioned a product called Langka which is used with the factory touch up paint to remove scratches and stone chips. Here's the website for Langka with a video on how it works: LANGKA Paint Chip and Scratch Repair

I watched the video and realized that I don't need to spend $40 to achieve the same results. The problem with touch up paint is that it's impossible to fill the scratch perfectly. Either you don't use enough paint and you can still see the indentation when you're done, or you use too much paint and you end up with blobs that are easily visible.

Langka's process is to blob on the factory touch up paint to get a perfect color match, wait 1 to 4 hours for the paint to dry, and then use their super-secret formula to wipe away the part of the blob that sticks up above the scratch. They wrap a cloth around something flat, pour some of their super-secret formula onto the cloth, and then wipe over the blob until it is flush with the original paint. You end up with touch up paint that perfectly fills the scratch without any blobs.

I realized that their super-secret formula is probably just lacquer thinner or some other solvent. The paint on modern cars is pretty much impervious to most solvents, at least if you don't leave it on too long. When I removed my side moldings last summer I used MEK, lacquer thinner, and "Goof Off" on the paint with no damage to it whatsoever. So this evening I decided to try the Langka method without buying the expensive Langka product. I used the factory touch up paint to fill in a bunch of stone chips in the front bumper. I let the blobs dry for about two hours, then I wrapped one of those blue shop towels around an old cassette tape case, poured a little lacquer thinner on the towel, and ran it over the now dry paint blobs. Voila! The lacquer thinner easily smoothed over the blobs. It was amazing! I then ran a wet rag over the bumper just to wipe off any remaining lacquer thinner residue. The lacquer thinner itself evaporates very quickly, but I didn't want to leave any residue on the paint.

I then went to a few old scratches that I had filled in with touch up paint a few months ago, and those, too, were easily smoothed out with the lacquer thinner. I have a lot more little chips to take care of. I'll try to make a video of it tomorrow or Wednesday. I took care of the bigger ones on one half of the bumper today. Now that those are fixed I'm starting to notice a myriad of tiny tiny chips that are about the size of the period at the end of this sentence. I'm going to try to fix those, too.

 

Waiting with anticipation for the video

 

I think I had originally posted somewhere else about the Langka. The way I had originally found out about this product was from a variety of other car forums where the subject of repairing paint chips showed up. When I used Langka on my Torch Red Corvette, the results were just so-so. It did the job of flattening the blob okay but the blob still did not quite match the original paint. On the other hand I used Langka to touch up my wife's Acura which was a dark blue metallic color and it was almost impossible to detect the chip fix.

The key thing about Langka is that the formulation absolutely does NOT harm any of the original paint--only flattens down the blob. I never came across anyone posting about Langka or other methods of dealing with chips who suggested using lacquer thinner as a substitute for the "expensive" Langka.

I would caution anyone against experimenting with solvents or other thinners in the hope of saving a few bucks--a miscalculation can result in a costly paint repair.

Doug

 

I'll post a video in a day or two showing what I'm doing. I agree that if you're the least bit concerned that the lacquer thinner will damage your paint, then don't do it. It's not something I'm worried about. Even on the Langka video they show how to test an inconspicuous spot to see if the Langka affects the paint. I did the same thing with the lacquer thinner back when I was removing my molding.

Factory auto paint these days is not affected by most solvents once the paint is dry. And the worst thing that could happen would be that I'd need to get my bumper resprayed. It pretty much needed resprayed anyway with all of the little stone chips, so I wasn't worried about doing any more damage than had already been done.

 

I think the paint formulation for bumper surfaces is different than what is used on the metal surfaces. At least that was the case with a BMW I once had where I wanted the body shop to touch up/respray the bumper/spoiler. The body shop guy was explaining the need for a special flex coat required for these type of materials. So it may be that the lacquer thinner works fine on the bumpers but maybe not so great on the metal?

Langka has been around for quite a while and this just seems like one of those instances where the possible risk involved to save a few bucks on touching up a $70K vehicle seems questionable.

Just sayin'

Doug

 

Will lacquer thinner harm car paint?

Will lacquer thinner hurt my car paint? - Yahoo! Answers

VitalAdvice - Will lacquer thinner hurt my car paint?

How To Remove Tree Sap From Car

http://www.autopia.org/forum/car-det...ver-spray.html

Lots of people say it's fine, including some professional detailers. My guess is that Langka is just buying lacquer thinner and reselling it for 50 times the cost.

 

Intriguing. We need your video fast, Rev

 

The only difference between the paint used on sheetmetal and flexible bumpers is the "flex agent" that is added to the paint. Every coat from the primer to clearcoat must have the flex agent added to the paint. It is not a special flex coat added after the fact.

If anyone is not satisfied with that, there are plenty of other inconspicous spots with painted sheetmetal to test the solvent of choice: inner hood panel, inner trunk panel, firewall, rocker panel, door jamb, engine compartment ...

In any case, all advice or techniques found on the internet, or indeed anywhere, ought to be used at one's discretion. Anyone who blindly leaps without thinking has only themselves to blame if something goes wrong.

It would be the same if someone used the Langka kit without thinking.

 

so long as you have a two stage paint job or better its ok to use thinner. just like a ladies nail polish, they first paint the color, let it dry and then paint the clear. a single stage paint job which is the color and clear mixed togethor will be all bad if you put thinner on there. if a two stage paint job has clear coat that is peeling or gone or whatever than dont do it because the paint is exposed. its paint thinner, not clear coat thinner :> you may see minor scratching from the towel if its fresh paint or a very dark color and a rough towel

 

I agree with this philosophy, particularly with ANYTHING you see on the web. Before I took a chance on Langka (actually it was several years ago) I googled and found a bunch of generally favorable posts on a variety of different car forum websites. The worst I found anyone saying about the Langka was that it sometimes did not work as flawlessly as their website suggests--real life users reported chip repairs varied from not-so-great to very good. Again, this seemed to depend on the type of chip/scratch and the color of the paint.


Doug

 

Yesterday I did the large chips on the left side of my bumper. Looking at it today in the light I couldn't even see where most of those chips used to be. A few of them are visible because I was either pressing down too hard while wiping with the lacquer thinner, or maybe I just went over those spots too many times. There were still lots and lots of tiny, pin-***** chips to fill. Those become more noticeable as the larger ones are filled. It's like when you look at the bumper you see 20 chips that need filled. As you work your way to the smaller and smaller ones you keep seeing more and more.

I just got back in from putting the paint blobs on the other side of the bumper. I also went back to the left side and started filling the tiny chips. In all I probably put paint blobs on 300 chips. The small ones really aren't that noticeable, but when I'm sitting on the floor right in front of the bumper I can see them, so I filled them. My car is about 700 miles shy of 100K, so it has accumulated a lot of chips. I was actually thinking about having the front bumper resprayed, but I think this will keep me happy for the next couple of years.

I made a video of what I'm doing, of course, so I'll try to get it posted this evening.

I understand Seismicguy's concern about the lacquer thinner, but I did my research before using it to remove the side moldings. Most everything I read said it wouldn't be a problem. The only people opposed to using it were the people who hadn't used it themselves. The detailers and other people who had actually used it on cars all said it was safe. Having said that, I understand if people don't want to use it. And if you're tempted but leery about using it, test it on an inconspicuous spot, such as under the hood.

 

Sam, Still happy with the results? I'm thinking about doing some touch up in the next few weeks. Thanks

 

I used Dr ColorChip on my front bumper and hood to fill lots of small chips last year when I bought the '04. It appears to be the same as Langka. It wasn't nearly as easy as advertised, but it did work. I forgot I had done it until about a month ago when I decided to go over the car with a DA polisher to remove some swirls from the paint. Well, it took the paint out of every chip that I had filled - and there were a lot. I would have expected year old paint to stick a little better.

 

Yep! I have a few more small chips I want to fill, but the bumper looks 1000% better than it did before. It's not perfect, though. I used the factory touch up paint that was supposed to match my car (same color code as what's stamped on the B pillar) but it wasn't quite a perfect match. The touch up is just a hair lighter than the paint on the car. It's only noticeable when you get within about 3 feet of the bumper. It still looks much better than the white flecks where the primer was showing through. I made a video, but it's kinda crappy because the sun came out between the "before" video and the "after" video. The sun is causing all sorts of glare, so you can't see the bumper very well. The process I used was essentially identical to the Dr. Colorchip or the Langka process, except I didn't smear the paint around. And then I didn't wrap the rag around a flat object. I tried that, but it seemed that simply wiping with the lacquer thinner rag worked best.

 

Mine had so many chips I repainted the bumper. Probably half a day's work and a better result in the end.