Fixing a Road Rash Area

[HarryD]

The lower side of my front bumper has road rash. I have some matching paint and would like to spray just this area. I am thinking I can just scuff with a green or red scotchbrite pad and top coat. The yellow under the red is the previous color.

Thoughts?

[962porsche]

if your looking not to see the chips though the new paint your going to need to feather edge the chips out. most likely you will need to sand it with 180 grit then a few coats of primer sand the primer with 400 or 500 grit then top coat with the paint.
depending if your top coating with base or single stage your final sanding grits could change.
for base clear I would opt to sand it with 500 or 600 grit.
for single stage 400 or 500 grit.
if your going to use a wet on wet sealer before your going to top coat you could also do your final sanding up to a 320 grit.

[Bill Douglas]

I don't know as much as 962, but I'll give my opinion.

I think the red hasn't been put on well if the red is chipping off down to the yellow. And the yellow is staying on as it should.

Depends on how much work you want to put it to it... But I'd be inclined to take all the red off the spoiler and clean clean clean then sand the yellow, a little primer for adhesion, then red and clear.

[962porsche]

Originally Posted by Bill Douglas

I don't know as much as 962, but I'll give my opinion.

I think the red hasn't been put on well if the red is chipping off down to the yellow. And the yellow is staying on as it should.

Depends on how much work you want to put it to it... But I'd be inclined to take all the red off the spoiler and clean clean clean then sand the yellow, a little primer for adhesion, then red and clear.

for sure by the time that's all sanded and feather edged it will be at least down to the yellow.

[Bill Douglas]

I mean ever single bit of red needs to come off as it's not adhering to the yellow. And if it doesn't come off now it will delaminate at a later stage with the new paint. It may even be rattle can paint.

[Dpmulvan]

There appears to be chipgaurd under that red on the lower part. Maybe I’m mistaking

[962porsche]

yup that area is chip guarded from the factory so it could very well be chip guard.
with all the chips on the rest of the leading edges if it was my personal car I would just buzz it down quick and seal and paint it. if at some point I would repair the rest of the panels that's when I would strip it back to bare metal and restore it as it should be.

[HarryD]

Originally Posted by 962porsche

yup that area is chip guarded from the factory so it could very well be chip guard.
with all the chips on the rest of the leading edges if it was my personal car I would just buzz it down quick and seal and paint it. if at some point I would repair the rest of the panels that's when I would strip it back to bare metal and restore it as it should be.

Great comments.

My plan is to scuff with 320, apply a coat of hi build primer and two coats of single stage color. I am not touching the frunk lid as I would need to do the whole section.

I just want it to all be red and I know it will return as I continue driving (abuse?) at AX and HPDE) for fun.

[962porsche]

I would not use 320 grit then put a primer over it . there is not enough tooth with 320 for the primer to adhere to. you would want to use a 180 grit the finest grit would be 220.

[HarryD]

Originally Posted by 962porsche

I would not use 320 grit then put a primer over it . there is not enough tooth with 320 for the primer to adhere to. you would want to use a 180 grit the finest grit would be 220.

Makes sense. Thanks for the input.

[Monkey Wrench]

I htink Id wet sand it with a rubber pad backing, it cuts faster kills the dust, and paper lasts longer.

then a hugh build primer and sanding more coats until you are happy ou can buy some glazing putty if you like to help feather any minor imperfections when you are completely happy with the surface and its even enough for you, then paint it.

Itll be brighter red probably you can decide if youd mind that..

if you like you can buy rockerguard or a product like that. it will likely leave a rippled effect. the ripples are a easy way to hide imperfections but if you are going for the OEM look you may not want stipple, you can decide all that.

I haven't used it foer years so Im not sure if the fomulations changed.. maybe ask a guy who's more in tune with the more recent products, my knowledge is admittedly a bit outdated and enviro laws changed a lot of the chemistry.

If you can get a two part epoxy product that might be a good move, I like to get two part epoxy down first, any color will do. maybe a epoxy primer.. Id probably look what I have and want o use up if I had other colors , then fine, its just a base coat. youll want the right mix for the topcoat.

maybe give the epoxy a little time to cure up , it might sand easier then and again I'd wet sand the epoxy with a wetordry paper. it will help it not plug the paper so much.

if you use a spray gun you can get a better spray pattern and have a more even surface, but even if you do a brush coat, its just a little more work evening things up , then a rattle bomb or HVLP gun is a little nicer..

a true bodyman may approach thigns differently and no doubt would do it faster than myself. maybe see what other reesponses you get.

could have been dirty or waxed between those paint layers who knows? if so the weak bond is going to still be there unless you cut through the red and get a toothed grip on the base. if the yellow is stuck ok Id call it a good base . if its loose, maybe paint stripper, or a sanding disc will get it off faster than hand sanding.

when you get to the topcoat you are wasting your more expensive mixed paint if its not even enough , things will jump out. if so you can do more buit best to leave the red until you are happy with your evenness of tha base.


I had to refinish some plastic for my rear bumper end , I bought one less squished and wished Id shopped for a more perfect one. I kept going at it and painting it and some underlying paint cracks transfered through and my finish wasn;t even enough..

eventually I used an epoxy and that worked . once I had a better base, I worked out the smoothness and evenness more.. then the paint cracks stopped telegraphing through. I then used high build primer and glazing putty. . it seemed to take me forever. my mistake was not stripping it right theough, and epoxying it first.

I tne repainted my bumper which was smooth and just faded, that went real fast because my base and my evenness did not need a lot of extra work. I thnk just used fine paper gavei ti a good wash and the OEM faded guards red was fine as a basecoat.

now my bumper is a lot more red and shiny than the rest, but thats something else to tackle.

if you try maybe you can get epoxy in guards red or whatever it is.. I htink they can load spraybombs with a two part epoxy but if you use it the whole can will harden up, Id ask others about that.
I just used basecoat and a clearcoat in a rattle bomb.. at least its not so stinky - I have no paint booth.
i have a decent gun but I was feeling azy , I didn't want to clean it lol..

[HarryD]

Originally Posted by Monkey Wrench

I htink Id wet sand it with a rubber pad backing, it cuts faster kills the dust, and paper lasts longer.

then a hugh build primer and sanding more coats until you are happy ou can buy some glazing putty if you like to help feather any minor imperfections when you are completely happy with the surface and its even enough for you, then paint it.

Itll be brighter red probably you can decide if youd mind that..

if you like you can buy rockerguard or a product like that. it will likely leave a rippled effect. the ripples are a easy way to hide imperfections but if you are going for the OEM look you may not want stipple, you can decide all that.

I haven't used it foer years so Im not sure if the fomulations changed.. maybe ask a guy who's more in tune with the more recent products, my knowledge is admittedly a bit outdated and enviro laws changed a lot of the chemistry.

If you can get a two part epoxy product that might be a good move, I like to get two part epoxy down first, any color will do. maybe a epoxy primer.. Id probably look what I have and want o use up if I had other colors , then fine, its just a base coat. youll want the right mix for the topcoat.

maybe give the epoxy a little time to cure up , it might sand easier then and again I'd wet sand the epoxy with a wetordry paper. it will help it not plug the paper so much.

if you use a spray gun you can get a better spray pattern and have a more even surface, but even if you do a brush coat, its just a little more work evening things up , then a rattle bomb or HVLP gun is a little nicer..

a true bodyman may approach thigns differently and no doubt would do it faster than myself. maybe see what other reesponses you get.

could have been dirty or waxed between those paint layers who knows? if so the weak bond is going to still be there unless you cut through the red and get a toothed grip on the base. if the yellow is stuck ok Id call it a good base . if its loose, maybe paint stripper, or a sanding disc will get it off faster than hand sanding.

when you get to the topcoat you are wasting your more expensive mixed paint if its not even enough , things will jump out. if so you can do more buit best to leave the red until you are happy with your evenness of tha base.


I had to refinish some plastic for my rear bumper end , I bought one less squished and wished Id shopped for a more perfect one. I kept going at it and painting it and some underlying paint cracks transfered through and my finish wasn;t even enough..

eventually I used an epoxy and that worked . once I had a better base, I worked out the smoothness and evenness more.. then the paint cracks stopped telegraphing through. I then used high build primer and glazing putty. . it seemed to take me forever. my mistake was not stripping it right theough, and epoxying it first.

I tne repainted my bumper which was smooth and just faded, that went real fast because my base and my evenness did not need a lot of extra work. I thnk just used fine paper gavei ti a good wash and the OEM faded guards red was fine as a basecoat.

now my bumper is a lot more red and shiny than the rest, but thats something else to tackle.

if you try maybe you can get epoxy in guards red or whatever it is.. I htink they can load spraybombs with a two part epoxy but if you use it the whole can will harden up, Id ask others about that.
I just used basecoat and a clearcoat in a rattle bomb.. at least its not so stinky - I have no paint booth.
i have a decent gun but I was feeling azy , I didn't want to clean it lol..

Thanks for your thoughts.

After I sand and glaze the surface. My plan is to use a high build primer (SEM) followed by PPG OMNI MTK (or Deltron)2 pack top coat. I may (Deltron) or may not clear (MTK) as well.

[Monkey Wrench]

I think you meant to say Deltron

https://www.ppg.com/en-US/refinish/products/deltron-nxt

im admittedly less informed about the newer coatings than some who are using them often and more recently. , Im certainly happy to learn more .

[HarryD]

Originally Posted by Monkey Wrench

I think you meant to say Deltron

https://www.ppg.com/en-US/refinish/products/deltron-nxt

im admittedly less informed about the newer coatings than some who are using them often and more recently. , Im certainly happy to learn more .

I stand corrected. The paint selected depends on what my supplier has available.