Advice for regraining a formerly painted car?

[Ethan Rode]

Hi Folks,
I recently became the new owner of 4972. Some may remember this as the white car that BHCC (The Great Satan of Project Cars) had for sale awhile back.
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Overall, the car is in really solid shape, but the white paint had to go. I removed all the panels, including the doors, and used Aircraft Remover and my pressure washer to strip the paint. Thankfully there weren't any really terrible surprises in terms of dents, but whomever did the body work used Bondo to level the panels, instead of making adjustments.
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However, under the Bondo, it looks like the car was hit with super coarse sanding disc which left areas of deep scratches all over the car.
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I'm hoping that someone has some wisdom regarding the proper way to deal with scratches this deep. I've had some success working the shallower ones out with a 120 grit flap disc on the grinder, followed by 220 grit on the DA sander, and then graining by hand with 80 and 120 grit. This works ok on the sides, where the metal is thicker, but I'm hesitant to use it on the top of the doors, or the hood (which is the roughest panel on the car). I know I'll need a Wolfhead, but I'm not sure if it will work out these horrible deep scratches. Any advice?

[David T]

80# grit sandpaper. On the hood you must be especially careful with your pressure or you can develop the X pattern because of the way the hood is supported underneath by the fiberglass. I would have advised to only remove panels that were dented and could only be fixed by taking them off. Taking off and reinstalling the panels and doors increases the work a lot because you must now realign them as you reinstall them. Using chemicals to strip the paint is very messy. You must make sure you have neutralized the chemicals completely. The metal is the same thickness on the whole car, 16 gauge unless it has already been worked on. It is probably better to sand the paint off rather than strip it since you must regrain anyway.

[Hill Valley PD]

80# grit sandpaper. On the hood you must be especially careful with your pressure or you can develop the X pattern because of the way the hood is supported underneath by the fiberglass. I would have advised to only remove panels that were dented and could only be fixed by taking them off. Taking off and reinstalling the panels and doors increases the work a lot because you must now realign them as you reinstall them. Using chemicals to strip the paint is very messy. You must make sure you have neutralized the chemicals completely. The metal is the same thickness on the whole car, 16 gauge unless it has already been worked on. It is probably better to sand the paint off rather than strip it since you must regrain anyway.

Funny you mention the X pattern. I never knew that was a thing until I attended DCS 2018. It seemed like pretty much all of the cars had it to some degree under the fluorescent lights. It's one of those things that once you see it, you cannot unsee it. Yet, another interesting quirk.

[HollywoodF1]

Funny you mention the X pattern. I never knew that was a thing until I attended DCS 2018. It seemed like pretty much all of the cars had it to some degree under the fluorescent lights. It's one of those things that once you see it, you cannot unsee it. Yet, another interesting quirk.

I've yet to see someone show some magical way to support that flat slab of hood from beneath so the surface can be worked on without stretching the surface over the x-support beneath it.

[Rich]

I've yet to see someone show some magical way to support that flat slab of hood from beneath so the surface can be worked on without stretching the surface over the x-support beneath it.

There is apparently no need to support the hood in any special way. Just give it to Chris Nicholson to work his magic on it. I believe the trick is to be gentle and patient so as not to bend or work the stainless panel very much. Not that I've done it. But I have watched him do it live. It's amazing.

LINK: Delorean Stainless Steel Repair And Refinishing Demonstration

[David T]

The "trick," if you want to call it that, is to use light, even pressure. Easier said then done especially when you have to lean over it. Takes a lot of practice.