Method for fixing deep scratches and rock chips

Rip great work..... the sticky is great and like an old friend here when you need it.

I'm going to use your method for my hood. BUT what about the bumper? I know someone mentioned how to fix a rock chip in the front plastic bumper, anyone have any ideas? Thanks

Originally Posted by schley

Rip great work..... the sticky is great and like an old friend here when you need it.

I'm going to use your method for my hood. BUT what about the bumper? I know someone mentioned how to fix a rock chip in the front plastic bumper, anyone have any ideas? Thanks

I'll chime in with my process for scratches. I detail for a BMW reseller here in Kansas and recondition 1-2 cars per week. It's low volume, but allows me the luxury of spending a lot of time getting these cars detailed.

Typically, the bumper and headlight covers are the toughest to do. I usually use 3000 grit and a SnapOn air sander to remove light scratches and prep the surface for compounding and glazing.

Here's a 745i that I'm in the process of detailing. The hood and front area had several scratches and lots of stone chips.



You can see how I started to dull the surface I'm working on


Here's a shot of the hood after sanding. The center portion had serious scratches and I dulled the paint quite a bit.


I have about 1/2 the hood compounded


Headlight and bumper are compounded and polished


Hood and front completed...time to compound and glaze the rest of the car


Shameless reflection shot of the driver's side compounded and glazed


Overall, plastic is the toughest part of the car (I've burned a few mirror housings with a rotary). Use lots of care, check your work many times during your work, and start with the least aggressive product.

Totoland

What is the part or model number of the Snapon air sander? Thanks

Originally Posted by rjcoston

What is the part or model number of the Snapon air sander? Thanks

I'll get the part number when I go to the shop tomorrow.

Totoland

Any further information on the sander? Thanks

Originally Posted by rjcoston

Any further information on the sander? Thanks

Doggone It! I wrote it down on a Post-It and it's still at the shop. I'll get the part number by lunch and post it. My bad!

Toto

Here's the link to the Snap On orbital

http://buy1.snapon.com/catalog/item....re&dir=catalog

Totoland

Originally Posted by Totoland

Here's the link to the Snap On orbital

http://buy1.snapon.com/catalog/item....re&dir=catalog

Totoland

Thanks

good one!

DISASTER - I had a rock chip with a few scratches, bought the Duplicolor scratch and chip repair kit. I used the clear coat, now it has ugly blob. I tried to sand it down with the sandpaper that comes with the kit, make things worst. I have haze around the repair and I tried to use the compound to polish it out, no use. What can I do? Help!

Originally Posted by 5Thirty

DISASTER - I had a rock chip with a few scratches, bought the Duplicolor scratch and chip repair kit. I used the clear coat, now it has ugly blob. I tried to sand it down with the sandpaper that comes with the kit, make things worst. I have haze around the repair and I tried to use the compound to polish it out, no use. What can I do? Help!

Give me some details on the chip and I can try to help.

1. Location of chip and size (pics would help)
2. Plastic body panel or sheet metal
3. What grit sand paper did you use
4. What compound did you use
5. Do you have access to a rotary polisher or pc

Holler back and I will try to step-by-step help

Totoland

Originally Posted by Totoland

Give me some details on the chip and I can try to help.

1. Location of chip and size (pics would help)
2. Plastic body panel or sheet metal
3. What grit sand paper did you use
4. What compound did you use
5. Do you have access to a rotary polisher or pc

Holler back and I will try to step-by-step help

Totoland

Hehe I feel so stupid...I have been using the wrong pad on my buffer
I changed the pad last night and used the compound that came with the kit...problem solved. I still have some more to sand, but now I feel much comfortable sanding since I know I can buff out the haze. Thanks Totoland.

Good to hear it worked out. That is ONE sharp vehicle you have!!!!!!

Take care

Totoland

So what is the best method to treat a 6" vertical scratch(from parking close to garage door) on plastic bumper, deep enough to feel with nails? Shall I start by using a 3000 grit on porter cable and then compound. Any recomendation for compound?

Originally Posted by LeMansX5

So what is the best method to treat a 6" vertical scratch(from parking close to garage door) on plastic bumper, deep enough to feel with nails? Shall I start by using a 3000 grit on porter cable and then compound. Any recomendation for compound?

If it's deep enough to feel with a fingernail, it might have scratched to the base material. You could certainly try 3000 grit and follow that with compound. Above all, take your time and work the area with the porter cable. Careful not to get the plastic too hot!...check the area you are working with the back of your hand for temp. If that doesn't work, you will be faced with building up the gouge using touch up paint (I'd recommend a hardener mixed to speed the process).

Toto

Originally Posted by Totoland

If it's deep enough to feel with a fingernail, it might have scratched to the base material. You could certainly try 3000 grit and follow that with compound. Above all, take your time and work the area with the porter cable. Careful not to get the plastic too hot!...check the area you are working with the back of your hand for temp. If that doesn't work, you will be faced with building up the gouge using touch up paint (I'd recommend a hardener mixed to speed the process).

Toto

Thanks.

After 3 years and 38k miles, I finally jumped in and tried this out on perhaps 20 or so tiny rock chips on my Imola Red ZHP. Most of them were on the hood and about 3 were on the sides of the car.

This process works very well. I will however tell you that I had a few 'problems' and will give perhaps a suggestion or two, but I'll let the experts chime in who have tried it and let them vote on it.

First off, the factory touch up paint I had was a little 'thick', so the paint turned out to be tiny little globs on top of the rock chips. I would suggest using a smidgen of thinner so that the paint flows into the chip. The pencil eraser is a good idea, but a pain to work. No real suggestion here, but I guess the main thing is to work in a small area.

I used 1500 and then 2000 wet/dry sandpaper. I wound up with little uneven parts in the paint where the paint was sanded down in the area around the glob. See the issue above which might help this. The repairs look a little like an old scar when you look at the paint from the side-you can see little round dimple-but you have to look really, really close.

I was using a wool pad and then a yellow compounding pad and Menzerna's Intensive Polish and it took me quite a bit to get rid of the scratches. I would go another round on a lighter sandpaper so that you'd spend let time with the porter cable. Perhaps 3000 grit. Also, with each successive grit, I would work further and further outwards to make a nice even sanding job. (See above).

I'd be curious to see what others experience is with this.

I just finished my car-Washed, clayed and then did the paint repair. Compounded the whole car with Menzerna Intensive Polish and then used the Menzerna Final Polish with the white pad. Final touch was the Menzerna FMJ with the red pad. I really dig the FMJ. VERY easy to apply and buff off. It took me less than 30 minutes to do the whole car. A little really goes a long way.

Tomorrow morning I start on the trim bits, wheels, then the interior. I guess this is the way I spend my 3 day weekends...

I did try to take some photos, but, nothing really shows the process better than what is already documented. Maybe tomorrow morning it will show up better in the sunlight.

Johnny

great tips guys, but i have a question. I have a quarter size chip on my front bumper. I tried paintpen, which is kind of a sharpie type pen. It came out like crap. can you repair a chip this big following this method? or do i have to have the ft fascia resprayed? I do have more scrapes.

Dude I Work In Body Shop And I'm Impressed. Just Don't Tell Everbody Our Tricks.

Brian ..

What an AWESOME post. You explained this better than the Complete Garage did when I took their seminar using Griot's products. I have the orbital and everything you've said is 100% correct. I have NOT had to fix a scratch yet (thank GOD), but using the polish, wax, clay etc is SOOOO easy and the orbital too.

I use these products as well .. and again: What an AWESOME post..

Question for you: I clayed on Saturday, and I realized with a hose running (I use warm water from the inside of the house. *soft water*) I could clay while the hose was going over the area keeping it well lubricated. Is this OK to do? As, most of the time I see posts on claying people say to use the Quick Detailing spray.

Can you use water, like I did. I did not notice anything wrong, and it looked gorgeous when I got done waxing. What do you say?

Thanks in advance for your thoughts ..

What touch up paint are you guys buying? If I have a bunch of rock chips and scrapes, would I be best off buying the paint pens or the paint & clear coat tubes? I figure the paint tubes would be best if we're to use little brushes/toothpicks.

Also, any worries over clear coats not being there after the wetsanding and polishing? Take a look at this pic, it's all over my roof. I'm completely open to having a professional take care of this but I'd like to try it myself first.

This was excellent information...BUT if I bring the car to a local auto detailer would they be able to fill in the chips so they become less visible?

Wow, great topic for car lovers! My two cents on a number of points raised (I'm a former detail shop owner and detailer)...

First, Griots has some fantastic applicators if you dont want to use the toothpick... part #50406. Work well when you use very little amounts of paint. They also have a nice tool for scraping the wax and crud out of the scratch before applying the paint (mine came with the applicators as a kit).

Second, I like to use a little bit of primer in the scratch. Many, many, many spot repairs come loose due to poor prep (cleaning) and lack of adhesion without primer. Any small quantity of automotive primer will do.

Third, practice on an inconspicuous spot first! Maybe your "significant other" has a car with a scratch or two that can be attacked without dire consequences... or else your winter whip.

Fourth, as mentioned earlier, Always start with the least aggressive approach for your compounds, pads, wetsand paper, etc. You can always get more aggressive when needed. More aggressive usually results in being too hard on the car's finish and that can cost you time, money, or both.

Fifth, when working on plastic with a machine - machines create heat and heat is not plastic's best friend. Keep it moving, don't stay in one spot, use your free hand to feel the surface in case it is getting warm. Paint will come off a hot plastic surface faster than you'll ever believe (especially with a pad moving at 1500-2000rpm)!

I hope that's useful to someone out there!

Question for you: I clayed on Saturday, and I realized with a hose running (I use warm water from the inside of the house. *soft water*) I could clay while the hose was going over the area keeping it well lubricated. Is this OK to do? As, most of the time I see posts on claying people say to use the Quick Detailing spray.

Can you use water, like I did. I did not notice anything wrong, and it looked gorgeous when I got done waxing. What do you say?

Thanks in advance for your thoughts ..



DarrenBMW - Using the free-flowing water is ok. However, I much prefer using a great big bucket of super sudsy water and a wash mitt. I have a bucket with a sediment tray so that heavy stuff (dirt) sinks and doesnt get caught in the mitt. The soap is a lubricant and is much more slippery than the water alone. That's why they always suggest a QD spray... it too is very slippery. However, the soapy water is MUCH cheaper than the QD spray. You can use your "soft" tap water in the bucket too, if you want. That's a good idea. As for warm vs cold water, I find the cold water is much more dense than the warm water and therefore more effective.

I hope that helps.

My first time using your method.

I tried a hole punch and pencil with eraser I took 1500 wet. Glue small sand paper "dot" onto pencil eraser to work on a scratch.

Worked great until I took it one step too far! Now just a little larger than an eraser head i have worn down to primer. Now on my TIAG car i have a light spot by the gas tank lid.

Not quite sure what to do... tried to buff a bit and no luck.

I have some touch up base and clear "globing" on that i will let settle for a few days before i work on it.

Be very careful, i should have used 2000 or 3000.