How best to fix a deep scratch in bumper cover?

[Computron]

Hi guys,

Need some advice here. Not sure if the attached pic below shows it well enough, but I discovered a deep scratch in my rear bumper cover about 1.5 to 2 inch long. It is deep and goes all the way through to the plastic. Have any of you had this type of situation before? I'm pondering how best to fix this.

I can touch-up paint it, but I know it won't match perfectly and won't be smooth after.
It seem like respraying the whole bumper would be overkill.
They have this spot repair option, but I'm not sure the paint matching and blending will be good enough to not be noticeable.

Also, will respraying affect the resale value? Even if I buy a brand new bumper cover, I would have to get it sprayed to match the color... would having a bumper cover replaced affect value as well?

Just wondering what the best option is. Any advice would be appreciated. Thanks!

The scratch is actually vertical. The pic below is rotated sideways for some reason.

 

[drew]

A detailer can fix this.

You can too with some 3M Rubbing Compound, 2000 grit sandpaper. Fill in the crack with touch up paint, lightly wet sand the area down, repeat until smooth and then polish up with 3M Rubbing Compound until shiny. Do this all with hand effort and no tools. You will be able to see it, but you will really have to look.

I'm guessing there are gazillion youtube videos on just this:
https://www.youtube.com/watch?v=CKU-koKtuMU just don't need the putty, just fill with repeated paint applications.

 

[Computron]

Thanks Drew,

I think the hardest part is getting touch up paint that truly matches my existing paint. I have 2 bottles of the genuine touch up paint from the dealer and they are both too dark based on other spots I have used them on.

Any ideas where to get the best match paint? Try another bottle from the dealer or get someone to try to mix it up?

 

[TxGlenn]

Thanks Drew,

I think the hardest part is getting touch up paint that truly matches my existing paint. I have 2 bottles of the genuine touch up paint from the dealer and they are both too dark based on other spots I have used them on.

Any ideas where to get the best match paint? Try another bottle from the dealer or get someone to try to mix it up?

I would try using a toothpick with your dealer touch-up paint and slowly apply it one tiny spec at a time. It is a slow process, but I imagine it will be hardly noticable even with a slightly darker paint (how much darker I guess?). You don't want to use the brush that comes with the paint for something like that.

Mixing it up will likely not be a match.

 

[tucsonsx]

The procedure that Drew posted will give as good a result as possible and is superior to removing the bumper, repainting it, and replacing
it esp. if your car has all original paint. The only thing I can add is that I have bought the best small brushes in several shapes and sizes from beauty shops like ULTA ( another benefit to being married ), the best touchup paint that I have found is from www.automotivetouchup.com , and since the touchup paint is lacquer you can feather the edge of the first few coats using a q-tip and lacquer thinner to reduce the amount of sanding. None of this takes any real skill just lots of patience because the scratch is vertical and on a vertical surface and the paint will run down after it is applied and will therefore require more coats than a scratch on a horizontal surface. The saving grace of this whole thing is that it is cheap and you can remove all the touchup paint any point, even years later, and be right back where you are now.

 

[Old Guy]

A bad re spray will detract from the car's value. A good re spray (on the existing cover after it has been properly prepped) should have no negative value on the car.

Drew's method may provide an acceptable result. Your observation about the touch up paint giving a slightly darker finish is valid. This is a problem with paints with any metallic / pearl component. This is typically caused by the metallic components in the paint dropping out of suspension which reduces the reflected light in the repair. Shaking the bottle repeatedly during the repair can reduce the drop out; but, in my experience never eliminates it. Also, If you do any post paint application correction / polishing to level the surface this removes metallic elements darkening the finish. The technique works pretty well for solid colors, not so well for metallic. As Tusconsx states, give it a try because it will not cost anything and if the result is disagreeable, you can usually remove the repair with a rag with acetone.

Given the width of the scratch, I would not attempt the repair with a bristle style brush. Go to a hobby shop that handles models and purchase a package of micro brushes - they look like the worlds tiniest Q tips).

https://www.micromark.com/Microbrushes

Don't get the regular size - these will be too big for a scratch. These will be better at getting paint into the scratch and have less blobbing over the edge. Do the repair on a cool day because this increase the working time / film set up on the paint - touch up paints tend to be really fast set up. You might want to consider diluting the paint a bit with acetone which makes the paint easier to apply; but, tends to increase the rate at which the metallic drop out of the paint. Fix one problem, create another!

 

[goldNSX]

Changing the bumper cover for a scratch -> WAY overkill
Repainting the cover -> overkill to some extent.
If the color match on the bumper cover is far off compared to the rear fenders then reparing in the hope for a better match might be an option. But if the color now matches good I'd try to repair it. Mainly because pearl and special colors are very hard to match and you might won't see the scratch anymore but have to deal other ill effects.

Ask the paint show you trust what to do. If he speaks you into repainting it for sure it might not be the right paint shop for your problem.

As the clear coat is scratched it looks horrible right now but with right skills you won't see it from a distance of more than 3 feet or so and that's what counts.

Hope this helps.

 

[tucsonsx]

Totally agree with goldNSX. When you are done with the procedure the only touchup will be where the scratch is now. Clear coat has made these repairs easier because all the sanding is now done on that so that the base coat is not affected. Even solid colors have tinted clear coat now so you definitely want to go easy on the sanding - anyone who has seen a R77 red sanded too much will tell you that it doesn't look good because the base coat has an orange tint and when too much of the purple tinted clear coat is removed the car looks orange in that area. After awhile when you forget where the scratch was it will take you awhile to find it.

 

[goldNSX]

...after awhile when you forget where the scratch was it will take you awhile to find it.

Well, the psychological dilemma is that you always know where it is/was and you think the little dust grain is stored in your memory like it's a big mountain until you see it again and have to admit that it's not that bad at all. It's a very strong psychological effect and it's the worst with any new car.
Keeping focused on a clear mind has been a big help to avoid heavy and expensive overreactions, maybe to the age and experience also helps a little bit.

 

[I_M_Legend]

Don't forget the clear coat. You can mix the clear with the paint prior to application to make things easier. This should give you a better color match.

 

[drew]

Yellow metallic is just hard to match. It is probably a triple coat: yellow, pearl and a clear. I don't know, but I suspect the pearl is why the touch-up color is darker.

The odds of having the whole bumper sprayed with less notice than just filling in the scratch are of very low odds. It is difficult to match the exact color and/or clear texture like factory. A spot repair will give best results regardless of all but the most extreme budget.


For those of you who want a car that is easy to match paint, then get a plain black car.

 

[Computron]

Thanks for all the tips guys. I talked to one detailer today and he said he can sand it down, apply a little bondo and paint match and repaint that half of the cover up to about the license plate area and blending it in there.

Is it just me, or does that sound like the worst of all options? At least with the touch up paint method, as you guys mentioned, I can remove it all at any time and be at where I am now. If I get a new cover or respray the whole thing, at least I know the bumper will be the same color even though it may not match the fenders and the rest of the car if not color matched well. Painting half of it seems like it will risk having a mismatch on the bumper itself and I’d be losing the original paint on half the bumper anyways, so why not just do it all. And I just hate the word bondo.

 

[drew]

Overkill. Just use touch up to fill in...just do a little every day for bit. Just paint, sand and buff and little as possible.

It is hard to to make it any worse than what you have now. So you have little to lose.

Filler/Bondo is ok, but not required.

 

[emac]

Agree with others, try to fix it yourself. If it looks like crap, then move on to another method. You can get those microbrushes on amazon. I use them all day long as an orthodontist, and some make their way home. I have had decent results using the method on this website:

https://www.drcolorchip.com/

 

[tucsonsx]

Thanks for all the tips guys. I talked to one detailer today and he said he can sand it down, apply a little bondo and paint match and repaint that half of the cover up to about the license plate area and blending it in there.

Is it just me, or does that sound like the worst of all options? At least with the touch up paint method, as you guys mentioned, I can remove it all at any time and be at where I am now. If I get a new cover or respray the whole thing, at least I know the bumper will be the same color even though it may not match the fenders and the rest of the car if not color matched well. Painting half of it seems like it will risk having a mismatch on the bumper itself and I’d be losing the original paint on half the bumper anyways, so why not just do it all. And I just hate the word bondo.

it is indeed the worst possible option and someone that suggests that has no concept of the level of obsession of the typical NSX owner. drew is correct that the paint is a 3 coat system ( I can't tell from the photo if the color is Rio or Imola ) and doing a little each day is the way to go. I have had very good results on another of my cars with Pearl White Multi-coat paint. If your time is a consideration you can probably find someone in your area to do it but it won't be cheap because it is time consuming. I am also going to try what I_M_Legend suggests and use a base coat and and then mixing some pearl and clear and trying to get it done with only 2 paints - sounds promising.

 

[goldNSX]

I'd vote against DIY in this case. I also vote against repainting the cover esp. if the car still the factory paint.

Look at the picture again. The scratch is NOT down to the plastic, the clearcoat is off, the pearl coat maybe too but only part - if any - of the yellow.
Even with a line of clearcoat in that groove it'll look 80-90 % less bad than now. If you haven't done DIY paintrepair before get a pro who does that kind of artwork every day and pay him extra for a good result.

Sanding right away? No. please. Clean it first, fill it up with clearcoat and then sand it down very carefully.

 

[Computron]

Ok, due to everyone's suggestion, I'm going to attempt to repair this on my own. Is it safe for a novice to wet sand with 3000 grit sandpaper without permanent damage to clearcoat? I'm just going to be filling that scrape over time until it is actually above the depth of the rest of the bumper and then sanding it down with 3000 grit.

Seems simple enough. Any thing I need to worry about with the sanding process? I was just going to spray with quick detailer and sand away.

 

[goldNSX]

Ok, due to everyone's suggestion, I'm going to attempt to repair this on my own. Is it safe for a novice to wet sand...

Well, that does not seem to include my recommendation then. :wink: Been there - done that - plus the faults a novice usually does of course but that was more than 10 years ago.
Don't take it personal, of course you don't have to do what suggest (let a pro do the (wetsanding) job, correction or whatever it needs), it's your car but I'm tired of giving advice right now and I'm out of this thread. Sorry for that.

 

[Computron]

Well, that does not seem to include my recommendation then. :wink: Been there - done that - plus the faults a novice usually does of course but that was more than 10 years ago.
Don't take it personal, of course you don't have to do what suggest (let a pro do the (wetsanding) job, correction or whatever it needs), it's your car but I'm tired of giving advice right now and I'm out of this thread. Sorry for that.

Thanks goldNSX… it's not that I don't want to take your suggestion. Trust me, I'd much rather pay someone to do it... it's not the cost or anything. Remember, I was willing to spring for replacing the bumper cover entirely if needed to get perfection. It's just that I talked to two detailing places around me so far, and they both wanted to sand, fill, and respray to blend with existing. No one wants to do the fill with touch up paint option. They said it won't turn out as well.

Based on that and the suggestions here, I figure the touch up paint option I can undo and go back pretty much to what I have now and then go the more drastic route if necessary later. If I let the detailers do what they want, there is no going back if they can't match the Rio Yellow well.​

 

[goldNSX]

The paint shop guy
- has an incentive to do more than it is needed.
- fears a bad reputation if he only does what the customer asks him for and he knows that it's a risk (for his reputation).

For example: if you go to a Mercedes dealer he sells you a Mercedes, obviously. You've asked a paint shop, so what would you expect from him? Yes, he wants to repaint it. What about asking a detailer or a guy who's in refinishing the leasing cars (you know: correcting stone chips, scratches, wear and tear and so on)?

I've first seen the red flag when you brought in the idea of changing the whole bumper which would guarranty that there will be a paint mismatch, just at another place. The second red flag was the idea of sanding it, a procedure you've never done before. Esp. as it is filling it with clearcoat first and sending afterwards or just like 'drew' supposed to do: a small amount in the groove every day.

Be patient and watch out for another honest and capable guy out there. The US is the country of unlimited freedom and possibilities. I live in Europe which is sozialsm. It's just a matter of finding the right guy for the task.

Good luck!

 

[tucsonsx]

My advice about feathering the edges using a q-tip with some lacquer thinner for the early coats of paint to reduce the sanding works. I also use a small piece of wood with rounded edges as a sanding block under the sand paper so that the touch up paint which is built up higher than the surface of the bumper gets the most contact. If you wet sand and check frequently how it is going it is hard to screw up with 2000-3000 grit paper. Remember no power buffing and be sure to have good lighting ( that is why paintless dent guys bring out the big light before they start ); garage flourescent is usually sufficient.

 

[Old Guy]

I like goldNSX's idea of first trying to fill with clear coat (I suggest a thinned clear coat). I suggest rather than sanding, after the clear has set up, gradually wipe off the build up of clear with acetone and a micro brush to try and bring the repair level. Wet sanding to bring it level is an option. You ask if you can do this without damaging the clear coat. That is a relative question. The sandpaper will inevitably touch the surrounding clear coat and remove some of it in the leveling process. As long as you don't sand through the clear coat I suppose that qualifies as undamaged. The problem is that it can be very difficult to sand off just a tiny area. That is why I am inclined to level with acetone and a micro brush and perhaps polish with some paint correction compound if you need to do a little final removal. If this doesn't give satisfactory results, a rag and some acetone will return the area to its previous unrepaired state and you can try over with color and clear coat or whatever process you choose None of the touch up paints are anywhere as hard / durable as an original automotive finish and acetone will make quick work of them - even 5 years later.

emac mentioned Dr Colorchip. I have seen decent results with that product on scratches; but, always on non metallic / pearl finishes. Worth a try because if you are unhappy with the result, odds are that a rag and some acetone will get you back to where you started in less than 5 minutes.

As a side note, pearl finishes come in both 2 and 3 coat versions. I think whether its 2 or 3 coat may be dependent on the paint vendor (and whether it is subject to that Tesla hype). My car is B501P and I had the front end re finished to deal with extensive stone chip damage. I went back and checked the body shop invoice and the invoice indicates a 2 part finish. This agrees with Honda 2001 Service Bulletin XL-1-00 which lists all the 2001 NSX colors being 2 step with the addition that New Formula Red uses a tinted clear.

The salient difference between metallic and pearl seems to be that pearl replaces the metallic component with mica or a ceramic of some ilk. In metallic you get pure reflection effects; but, in pearl you get some refraction (and perhaps diffraction?). This last point may be a really good reason for not attempting a partial panel repair (blending). The refraction effect may be quite sensitive to the particle size and since you are never going to get the exact same paint as used by the factory, small differences in the particle size may create differences in the pearl effect. This might not be obvious across two panels boundaries; but, may become obvious if the repair is attempted within a single panel.

 

[goldNSX]

emac mentioned Dr Colorchip. I have seen decent results with that product on scratches; but, always on non metallic / pearl finishes. Worth a try because if you are unhappy with the result, odds are that a rag and some acetone will get you back to where you started in less than 5 minutes.

I agree with that. Have a look at the scratch again, it's the clearcoat that is scratched (white). With some luck the color below the clearcoat is ok. Using a color based paint pen would make it definitly worse, it will look absolutely horrible and will be a shot in the oven. Then it's the better option to not do anything at all.

My try would be:
- Clean it and degrease the groove.
- Fill (only!) the groove up with clear coat in several steps (needs a very fine tip and good eyes and calm hands), a small amount each day and let it cure (maybe tinted one, your (3rd) paint shop can help you out with mixing a tinted clear coat). With the first coat of clearcoat you'll see what's going on. I bet that the white scratch is significanly reduced.
- The final clear coat should be a little bit higher than the rest of the paint on the panel. That way you don't have to sand the hell out of it to make it level. Too much clear coat is bad either. You'll be surprised how a single coat shrinks as it dries. That's why you need maybe 3-5 coats.
- Some maniacs (like me) would take a razor blade and shave the excessive clear coat off -> again: less sanding necessary but I vote against doing so as a novice. See what I mean in 6:15 in this video: https://www.youtube.com/watch?v=q-R8pTniSAM Not sure about the product the sell but you can do it with the clear coat as well.
- It's sanding time then
- if 90-95 % of the initial scratch is removed I'd happy with that.

 

[Old Guy]

- Fill (only!) the groove up with clear coat in several steps (needs a very fine tip and good eyes and calm hands), a small amount each day and let it cure (maybe tinted one, your (3rd) paint shop can help you out with mixing a tinted clear coat). With the first coat of clearcoat you'll see what's going on. I bet that the white scratch is significanly reduced.

You refer to paint from a 'paint shop'. Are you suggesting using commercial OEM style finishes as opposed to touch-up (non-professional) repair paints which are typically lacquer-like paints? If so, that probably rules out the use of acetone as a go backwards option or as a tool to remove excess paint in the application process. Once set up, OEM style paints will be hard and definitely sanding / abrasive compounds are the only option for blending / leveling into the surrounding surface.

Two other things to consider.
1 ) The base coat is typically the high product cost; but, the clear coats are not super cheap. Depending on the product line a litre of clear can easily top $100. I really know zip about modern water born / low VOC finishes other than they are harder to work with. The older style urethane clears typically require an activator and once activated you are using all of it up right now because tomorrow its junk. You can try and divide the quantity down and activate small individual batches; but, it is harder to mix small amounts accurately.

2) Tinting the clear could be interesting because that might force you to purchase some of the base. That could be very expensive and you would have to know whether the base and clear are intermixable (which is different that being compatible when sprayed over top).

You are a brave person to try using OEM style finishing products. The touch up / lacquer-like paints are nowhere near as durable; but, you can probably safely tint the clear with the base and thin them easily. If the repair turns out bad, a rag and some acetone and there is no evidence of your goof-up.

 

[goldNSX]

You refer to paint from a 'paint shop'. Are you suggesting using commercial OEM style finishes as opposed to touch-up (non-professional) repair paints which are typically lacquer-like paints? If so, that probably rules out the use of acetone as a go backwards option or as a tool to remove excess paint in the application process. Once set up, OEM style paints will be hard and definitely sanding / abrasive compounds are the only option for blending / leveling into the surrounding surface.

Yes.
I usually spray a small amount in the cap or the spray can, let it dry/thicken for 10-20 sec. and use a very small, sharp edged brush to fill exactly that groove. You need very good eyes and calm hands (dentist-like). It might need several coats until the groove is completly filled up. -> razor-blade -> sanding/leveling -> polishing -> finished.
In the US, you've far greater choice, you might be able to buy a tinted version of the clear coat in a spray can. In Europe, I'd go to my paint guru who'd mix a tinted clearcoat for touch-up application ($20). After showing him the scratch he knows what to mix/to do. Not sure if it needs a tinted version in that specific case, depends on how deep the groove is. I might try with non-tinted clearcoat only.
I'd stronly vote against a color/clearcoat combo in that specific case. It will look worse esp. on yellow.
Better try that technic on another car first. Take a key and scratch the fender of your wife's car for example :wink: (better not ). If only the clearcoat is affected you'll see that it will look very acceptable. You might see from a distance of 10-20 cm that it's must have been repaired but not from 1-2 m or more and that's the key.