Erase ancient markings
January 18, 2019 12:01 PM   Subscribe

I have a vintage electronic device with a powder-coated metal case. When I bought it, long ago, police used to recommend marking your social security number on your gadgets for identification in case they were stolen. Ah, more innocent days. Now I want to sell it on eBay and I can't get the SSN off of it!

This was a very long time ago, and I have no idea what I used to mark it - possibly sharpie or paint pen. It's not etched or scratched into the surface. Things I've tried to use to remove it, with no effect at all:

* rubbing alcohol (quick wipe; long soak and wipe)
* a Magic Eraser abrasive sponge
* GOOP-brand hand cleaner
* WD-40 (quick spray and wipe; long soak and wipe)
* scribble over it with a sharpie and then wipe with alcohol
* scribble over it with a dry erase marker and then wipe with alcohol
* soak with apple cider vinegar and wipe

I'd rather not go at it with sandpaper, because that might make it harder to sell, but that's probably better than sending it out as is. Any suggestions?
posted by moonmilk to Grab Bag (23 answers total) 4 users marked this as a favorite
Fingernail polish remover?
posted by mochapickle at 12:07 PM on January 18, 2019 [6 favorites]

Can you cover it up with a silver paint marker?
Or scribble with a permanent marker first (try turning every digit into and "8" rather than just random scribbles) and then cover it silver paint. It won't look like new but hopefully it won't be too ugly.
posted by metahawk at 12:10 PM on January 18, 2019

Response by poster: My worry about covering it up is that the buyer will want to clean it, and if they successfully remove the coverup, they'll find the number!
posted by moonmilk at 12:12 PM on January 18, 2019 [1 favorite]

What about baking soda or something like bon ami powdered cleaner, for a little bit of grittiness without being full-on sandpaper?
posted by teremala at 12:18 PM on January 18, 2019

If it's Sharpie, ACETONE nail polish remover.
posted by ljshapiro at 12:26 PM on January 18, 2019 [9 favorites]

Acetone, which is sold as nail polish remover at any grocery store or pharmacy.
posted by FirstMateKate at 12:32 PM on January 18, 2019

I agree with acetone (which is most, but not all, nail polish remover--the cheapest stuff is likeliest to be most appropriate here). It will also soften or dissolve the protective plastic layer on wiring, so I'd be very careful about where it gets applied.
posted by tchemgrrl at 12:34 PM on January 18, 2019 [1 favorite]

Be very careful with acetone if there is any plastic at all. That stuff will melt certain types of plastic like butter.

I might try using a razor blade as a scraper. Don't hold the blade like you're scraping off a paper label, but hold it almost vertical, with two hands (one on either side of the blade), bend it forward ever so slightly (to stiffen it) and push it forward over the markings. Scrape very lightly.

Beyond that, I know you don't want to use sandpaper but you could use fine sandpaper, maybe 220 grit, and work up a few grits until any scratches are almost gone. If you really want to get fancy, get a set of Micromesh pads and work your way up the colors.

You might also try a Dremel with a wire wheel. Use goggles.
posted by bondcliff at 12:43 PM on January 18, 2019 [1 favorite]

Actually, Sharpie comes off with sufficiently-strong Isopropyl Alcohol (+90%). Or try Goof-Off. The "no effect at all" makes it sound like paint. You may have to abrade and polish it off mechanically, like with a Dremel and sanding disks.
posted by Kirth Gerson at 12:45 PM on January 18, 2019 [4 favorites]

Also, you could try Naptha (it's basically what lighter fluid is), which you can find at Home Depot where the paint thinners are located. Or just use lighter fluid. Wet a cloth with it and wipe. Let the cloth dry out before throwing it away.
posted by bondcliff at 12:47 PM on January 18, 2019

Do you have space to go the other way, and add numbers to obscure the fact that it's a social security number? I would instantly recognize 123-45-6789 as an SS# but 123-45-678901234 might not register. 456123-45-678901234 absolutely would not (unless your buyer reads MetaFilter).
posted by ubiquity at 12:52 PM on January 18, 2019 [5 favorites]

As a chemist used to getting sharpie off things:
The comments about acetone are 100% on point, including the ones about being careful not to dissolve the plastic. I would test it on a very small corner or out of the way spot.

People are right: Nail polish remover is a good source of this, all the bottles I've seen say if they have acetone in it on the back, so check for that.

Widex has ammonia in it. If acetone doesn't work, that wouldn't be a bad choice. Again, test a small patch. Its pretty powerful: It will take the coating off our lab benches.

You've tried rubbing alcohol (isopropyl alcohol) which is my go to for removing sharpie, but I've never tried to remove sharpie after THAT long. I've found in past that ethanol (drinking alcohol, something like everclear) is a slightly better solvent, but if you don't see ANY change after isopropyl alcohol I doubt anything in that series will do much of anything.

Lighter fluid is butane. It....well, it wouldn't be my go to, but if what you used isn't actually sharpie and nothing else touches it, you might try it. I would go with hexanes (gasoline) first though, its a bit easier to work with. I've never used butane as a cleaning tool or lab solvent, too high vapour pressure, but hey, give it a try. These are good for oil or grease based pigments. However, they are both going to be rough on a lot of plastics so be careful. Wet Q-tip to start with?

As a note: I would do all of this in a ventilated area or outside, and wear gloves (I don't have my safety charts on hand to tell you if latex or nitrile are better for these solvents, sorry).

Are you near a university with a chem department? If you are, there is a good chance there are some broke grad students who will take money to try a wide variety of solvents on it that you can't easily get (with good reason).
posted by Canageek at 1:22 PM on January 18, 2019 [8 favorites]

Yup, acetone or naphtha (aka Zippo lighter fluid -- imo avoid Ronsonol brand if you have a choice, it's less refined and therefore stinkier).

Personally I'd try acetone first, since if naphtha was going to do the trick I'd think a WD-40 soak would too.

(and for the record, naphtha works as a Goo Gone substitute too)
posted by neckro23 at 1:23 PM on January 18, 2019

If it's Sharpie, I might just make a little rectangle of Sharpie to cover it artistically; then let it set for a couple of days, and try to remove the covering Sharpie rectangle (to make sure the next owner won't be able to do it).

Really, though, it's your SSN; just excising it somehow is probably the best bet. Just do it in a controlled way so it doesn't look sloppy.
posted by amtho at 1:34 PM on January 18, 2019

I'm a pro signmaker that uses Sharpies for changeable text. Isopropyl alcohol is not the best remover for old Sharpie. Denatured Alcohol will usually do the trick. If the writing has deepy penetrated the surface it may take several tries.
posted by a humble nudibranch at 2:39 PM on January 18, 2019 [2 favorites]

Fine auto buffing compound?
posted by Raybun at 4:11 PM on January 18, 2019

...just popping in to say: REMEMBER TO MASK!

Whatever solution you choose, remember to mask off nearby surfaces you don't want affected.
posted by aramaic at 6:25 PM on January 18, 2019

Canageek: "Lighter fluid is butane. It....well, it wouldn't be my go to, but if what you used isn't actually sharpie and nothing else touches it, you might try it."

This lighter fluid, not this.
posted by Mitheral at 10:03 PM on January 18, 2019

Other people have probably already mentioned whatever solvent(s) in it made it work, but my mom always kept a bottle of cheap hairspray in the laundry room for inkstains. So, maybe worth a try?
posted by abeja bicicleta at 3:38 AM on January 19, 2019

Response by poster: Thanks for all the suggestions! I'll do another round of erasing attempts soon, and report back.
posted by moonmilk at 10:07 AM on January 19, 2019 [2 favorites]

Response by poster: Update: I still haven't had a chance to try nail polish remover / acetone or denatured alcohol. I did try a long soak and scrub with Dr Bronner's peppermint soap (DID NOT DILUTE!) to no effect.
posted by moonmilk at 7:37 AM on January 26, 2019

Response by poster: Update:
* denatured alcohol - no effect
* acetone - the first substance to have any effect at all! It marred the finish of the case but left the writing completely untouched!

I might just give up and keep this thing forever instead of ebaying it.
posted by moonmilk at 1:50 PM on January 27, 2019 [3 favorites]

Response by poster: Okay, I gave up and hit it with an orbital sander. That did the job and It doesn’t look as bad as I feared!
posted by moonmilk at 4:58 PM on February 5, 2019 [4 favorites]

« Older What happens after impeachment?   |   I'm in NYC. What is the best way to renew my... Newer »
This thread is closed to new comments.