Paint scratch to metal...what to do.

[mstrjon32]

I was pulling my Saturn Sky onto a drive-on lift last week, and the previous person on the lift carelessly didn't put the lift all the way down, it was maybe 1cm above bottom. Well, that 1cm was enough that as I pulled up onto the lift, the edge of it caught the bottom of the car, and scraped some of the paint down to the metal, and made a small dent. The damage is invisible unless you are underneath the car, so I'm not too worried about the appearance of it, but I am very worried about rust developing where the metal was exposed.

I used some rubbing compound to clean up the scratch, and then washed it out with soapy water and then flushed it with clean water, and waited a while for it to dry. I put three coats of the factory touch-up paint on the scratch over a 24 hour period, but I'm not convinced that this whole episode wasn't enough to begin the whole oxidation process. The bare metal was showing in an area about 4cm long, and I know I'm supposed to use some kind of primer on it, but I didn't have any and didn't want to leave this unexposed until Monday.

So, now I'm at a loss: Do I leave it alone, hope for the best, and keep my eye on it, or should I just take it to the body shop and have it professionally fixed before it becomes a problem. I'd rather not spend €500+ on this, but I'll be much more upset if it starts rusting and turns into a major problem.

https://dl.dropboxusercontent.com/u/69330674/IMG_4047.jpg
https://dl.dropboxusercontent.com/u/69330674/IMG_4056.jpg

[jamesboyy]

From what you are saying it sounds like you did a perfect job now i would say leave it be but since you are worried about rust your best bet would be to get a Lens Diameter Inspection Tool this will let you see if there is still any bare metal still exposed that the naked eye cannot see so you can correct it the missed spots ....good luck

[swanicyouth]

This is what I would do. I would so all that you did, plus measure out a piece of PPF film in the shape of the scratch, only slightly larger. Then I would IPA the area and apply that little piece of PPF in manner can't be seen unless your are underneath the vehicle, sort of like a Band Aid.

PPF will mechanically seal the area so no water can get to it, if its a quality film. Another option is you can tape off the area (except the scratch) and apply rubberized undercoat to it from the can. I recently used a bed liner version of this stuff and it dried super hard and doesn't come off after pressure washing.

[mstrjon32]

Thanks for the advice.

jamesboyy: I will order an inspection tool and take a closer look at it next week, that is a good idea. You say I did it "perfectly"--what about not applying some type of primer before the touch-up paint. That is my main concern at this point. I did this without any primer because I wanted it covered right away, but is the paint alone going to provide enough protection against moisture? Will the repair last without the primer?

swanicyouth: I think putting some film is going to be in order for this, eventually. I might actually put film on both sides, running the length of the car, maybe extending 5cm from the inner edge of the paintwork. As you can see in the photos, this area is highly prone to damage from road debris anyway, and the film is so strong that it probably would have prevented the paint from even being damaged in this incident. I'm just sorry it wasn't on there before...

[rmagnus]

OP not really sure what I'm looking at in those pics. Where is that round hole located on the car.

First of all painting bare metal is a temporary fix. I usually put clear nail polish on dings and scratches that go to metal until I have time to fix it right. Even a coat of WD40 will prevent rust.

Metal needs primer then paint. You can cover up the area as suggested. Removing oxygen from the metal prevents rust.

[mstrjon32]

rmagnus: Yes, that's what I was thinking. I'm not really equipped to do the work to fix this correctly at home so I think it's just going to have go to the body shop. We'll see what they say for costs and damage tomorrow.

The picture was intended to show where the scratch was, and the touch-up paint I put on it. Here's another one with the area where it cut through to the metal highlighted. The hole you see is normally there, I suppose to allow water to drain from...somewhere?

The scratch actually ran the length of the car between the front and rear wheels, but it came out with rubbing compound pretty much everywhere except on/near the highlighted area.

https://dl.dropboxusercontent.com/u/69330674/IMG_4053.JPG

[sjb89]

Why is this thread extremely wide ?? Very hard to read.

[jamesboyy]

[QUOTE=mstrjon32;961100]Thanks for the advice.

jamesboyy: I will order an inspection tool and take a closer look at it next week, that is a good idea. You say I did it "perfectly"--what about not applying some type of primer before the touch-up paint. That is my main concern at this point. I did this without any primer because I wanted it covered right away, but is the paint alone going to provide enough protection against moisture? Will the repair last without the primer?

The reason why i said you did it perfectly because you didn't wait you acted immediately and that is prefect yes using a primer before applying body color would have added more protection/ better bond but as long as the scratch is fully touched up you should have nothing to worry about

[mstrjon32]

I took the car to the body shop today and the owner looked at it and said it should be fine with just the touch-up paint on there. I suppose I believe him, but I might still get some primer and a can of base coat in an aerosol can, remove the touch-up paint, and fix it properly. I was ready to just hand over whatever cash was necessary to undo this mistake, but he was quite adamant that it would be OK...

[mstrjon32]

Well, today I ordered some sand paper in various grades. Tomorrow, I will try and get some primer and more of the correct color paint. I may put the car back on the lift tomorrow and see if I can gently work the small dents out of the metal. Once the sand paper arrives I will remove the touch-up paint I put on last week, properly prepare the surface, and then put down new coats of primer and paint.

I did a little more research as well, and it looks like if this panel is ruined it can be replaced--though I'm not sure where I would source a new one and it will require a professional to install (involves replacing the adhesive and making 3 mig welds).