Cross Hatch Sanding Marks

[citadel]

Hi guys

We bought a restored 1970 car that was painted about 8 years ago. It has cross hatch sanding marks. Any ideas if these can be removed?

[Michael Stoops]

Re: Cross Hatch Sanding Marks

They should come out, but depending on how coarse they are and what sort of tools you have available to you it's either a straightforward process or.... well..... a lot of work! Generally speaking, we like to see sanding marks refined to 3000 grit as the buff out is then far less invasive to the paint that grinding away with a rotary buffer and an aggressive pad/compound combination. It's also just plain easier. Since you just purchased this car we assume you have no info on what the actual sanding process was, and it's possible that what you're actually seeing is aggressive sanding marks that originated in the primer and were only revealed when the paint subsequently shrank. A heavy application of primer quickly followed by color and clear coat layers can cause this to happen - as all these layers of paint eventually out gas over time, they shrink back and aggressive sanding marks in the primer sort of expand and draw the rest of the paint down with it. This usually can't be buffed out, but it can be wet sanded out to flatten the clear on top which ultimately results in a flattening of the overall finish.

So, simple sanding marks in the clear are quite straightforward to remove, provided you have the necessary tools and skill to use them. Sanding marks in shrunken primer are a bit more difficult to fix as the process becomes much more involved, and opens you up to a greater risk of damage if you've never done this before.

Any chance you might be able to provide an image or two? We know this sort of defect can be tricky to capture on camera so experiment with angles and light if need be.