How does one buff and polish a light scratch on a Model M?

[LewisR]

There is a slight horizontal scratch between the number row and F-key row on a Model M SSK that I just got. I am having a very difficult time capturing it on my camera, but it's much more noticeable in person. How would I go about buffing and polishing this a bit to smooth it out so it's not as noticeable? I'm pretty anal about this, so I want the best finish possible.

SSK_scratch_01.jpg (753.31 KiB) Viewed 2488 times

[Wodan]

With a surface like that, I guess only sand blasting can give you good results.
But you'd have to experiment with various grain sizes and pressure settings to find the right combination to blend in with the rest of the case.

Or just pick your favourite result and blast the whole case

[LewisR]

Haha! Yeah I can see myself doing that. I think whatever I do will have to take time as I don't want to remove the existing texture. I don't expect to fully get rid of the line, but just blend it in better. The texture is mostly fine since it's not a deep scratch, it's mainly how the light reflects from it that is a bit unsightly. I was thinking of using an eraser to buff it out a bit and then polish it back up lightly somehow.

[fohat]

An eraser would be one solution. If it were mine I think that I would get a lightly abrasive kitchen cleaner such as Barkeeper's Friend or Ajax (US brands), wrap a wet cloth rag around my index finger, dip it in the pile of powder, and rub the scratch in a gently swirling motion. Do this on the case shell with the keyboard apart, of course.

Getting the scratch out is the easy part. The more difficult part is that you are likely to erode the surface texture in doing it, and leave a shiny spot. If the scratch is deeper than the texture, it is almost inevitable that to remove one, you will remove the other.

Maybe just give it one quick pass to soften the look, like using "smudge" or "blur" in Photoshop.

[LewisR]

I definitely want to remove little if any existing texture. A quick pass would be good, and with as little actual buffing as possible. I had an idea that maybe a soft piece of leather would be a good polishing material.

I think I'm going to have to find a broken Model M to try on. I'd really like develop some good techniques to do this but it's going to take practice. I'll definitely share anything I learn.

I'd love to hear anymore ideas on methods to remove blemishes from these cases.

[LewisR]

With a surface like that, I guess only sand blasting can give you good results.
But you'd have to experiment with various grain sizes and pressure settings to find the right combination to blend in with the rest of the case.

Or just pick your favourite result and blast the whole case

Hey, I just saw your thread on sandblasting caps and now I see what you mean. Perhaps I could try that someday when I can use a sandblaster. Those results really surprised me!

[elecplus]

Visibility on scratches is usually due to imbedded dirt. Have you tried Spot Shot carpet cleaner? http://www.spotshot.com/It will remove almost everything from grease pen to lipstick to Magic Marker, but it does not harm the IBM cases. I have used it for years. Once the dirt is gone, the scratch might not be visible. Try spraying a tiny amount on an old toothbrush, and brush in the direction of the scratch.

[LewisR]

Visibility on scratches is usually due to imbedded dirt. Have you tried Spot Shot carpet cleaner? http://www.spotshot.com/It will remove almost everything from grease pen to lipstick to Magic Marker, but it does not harm the IBM cases. I have used it for years. Once the dirt is gone, the scratch might not be visible. Try spraying a tiny amount on an old toothbrush, and brush in the direction of the scratch.

I haven't tried that particular product but I have cleaned the area with a bit of alcohol. Basically, there is a long line across the board where there's about a 1-2 mm width with a flattened part the texture's ridges, so light reflects more evenly from it than the rest of the surrounding texture. I think, short of sandblasting, I am going to have to just deepen the valleys within the texture itself with a miniature carving tool, because buffing will only flatten the texture more. I did a bit of buffing with an eraser to blend it, but it's going to be a months long process, I think, to fully restore it. I'll need to come up with some tools that can carve that small, and some sort of magnifying glass to wear. If I can get some good macro shots, then I'll show what I mean, or I will make some illustrations.

[fohat]

I'll need to come up with some tools that can carve that small, and some sort of magnifying glass to wear.

If you have really steady hands, you might use a very small burr-end tool (perhaps a tiny Dremel bit - without the Dremel itself, of course!) and gently swirl tiny circles in the floor of the depression so that it is no longer shiny down there.

[Invisius]

I'll second Barkeep's Friend and a little water for this stuff, microfiber cloths give just the right amount of control without further scratching or just being too slippery. Makes a nice paste that's not too messy and doesn't bleach the case.

I've made junkyard trash looking boards with ink, permanent marker, glue, etc look brand new from the factory. The really deep stuff might end up having a slightly smoother texture, but unless you're using a microscope, nobody is going to notice.

[LewisR]

I ended up just trying the Barkeeper's Magic. I think it worked well enough. You can still see the line, but it's blended in a lot better. Thanks a lot for the advice!