Removing paint/ink logotypes from bare aluminum w/o damaging the finish?

February 20, 2013 12:47 PM

Paint Removal/Solvent Experts: Looking for solvents/methods for removing paint (ink?) logos from semi-glossy aluminum bicycle parts, without damaging or changing the finish. Detailed pics inside.

Looking to "murder out" my components (as the kids are calling it) and remove the screened-on paint (ink?) logos.

Here's what we're working with in a nutshell; A bunch of slightly different finishes/textures on bare(?) aluminum:

• crankset — [ detail ] — (material: unnamed aluminum alloy, anodized)
• seatpost — [ detail ] — (material: unnamed aluminum alloy)
• stem — [ detail ] — (material: 2014 Aluminum)
• [ all images ]

I'm looking for a solvent/method that will gently remove these paints (inks?) from the surface without changing the appearance of the underlying or surrounding metal.

I own a Dremel tool and have a big-box hardware store a mile away.

Not so much looking for conjecture or speculation -- this crankset would make for an expensive experiment -- looking for expertise in solvents or people who have performed this or something similar. Which approach(es) have you used that has given good results? Many thanks for your time and your expertise.

posted by jjjjjjjijjjjjjj to sports, hobbies, & recreation (13 answers total)

I'd start with MEK.
posted by Confess, Fletch at 12:55 PM on February 20

Acetone or brake cleaner are pretty good solvents.

You'll run into issues issues where the ink you want to remove is below a clear coat. If so, you're probably looking at a repaint.

The crankset and seatpost are good candidates for removal - there's not a clearcoat on top of these normally. Can you feel a ridge from the ink on the stem?
posted by dobi at 1:04 PM on February 20

Oven Cleaner may work, but might also strip the anodization.
posted by Confess, Fletch at 1:21 PM on February 20

> I'd start with MEK.

I've worked with the stuff quite a bit, but every shop I've been in has always cautioned against using it on anodized (or otherwise oxidized) materials because of it changing coloring.

I did a quick google search, and there's quite a bit of folks cautioning against it. (As well as some folks saying "it's fine", just for full disclosure -- but I can't afford to offer up my crankset in the name of settling this debate.)

> Can you feel a ridge from the ink on the stem?

There's no (or: "an imperceptible") ridge; but the texture under my nail seems quite a bit different/rougher on the painted (inked?) parts? I guess it doesn't feel like there's a clear over it... but I'm far from an expert.

> Oven Cleaner may work, but might also strip the anodization.

Yeah, we don't want this. From question: "solvent/method that will gently remove these paints (inks?) from the surface without changing the appearance of the underlying or surrounding metal...", and "Not so much looking for conjecture or speculation -- this crankset would make for an expensive experiment..." Thanks, though.
posted by jjjjjjjijjjjjjj at 1:25 PM on February 20

MEK is a good option, as is any acetone. With bike parts, you're going to end up with ghosting of the logo for a while. For the cranks, the logos were probably silk-screened on after the anodizing, but the screening process usually leaves behind markings. Typically I'd use a bit of solvent to do the bulk of the work, the use a buffing/polishing wheel to do the rest. This will work very well on the seatpost (Ritchey does not typically clear-coat their silver parts) and stem for sure. It will work poorly on the cranks unless you're going to re-polish the whole set. I don't have a set of those cranks here right now (Ultegra, it looks like), but Shimanos I do have look like the logo was screened on and they're from the last few years. The cranks will be VERY fussy about this because they're matte finished and will not take to polishing.

This is peripherally part of my job, so we're trying these things all the time. For the best possible results, you need to strip/polish then re-anodize.
posted by komlord at 1:25 PM on February 20

Oven Cleaner may work, but might also strip the anodization

This is very likely to pit or otherwise damage the aluminum. Strong bases are not good for the oxide/anodized finish at all. This is one of the ways used to remove anodization, in fact.
posted by bonehead at 2:14 PM on February 20

OK. Anodization is just a thick layer of aluminum oxide with dye encapsulated in it. So yes, any solvent that attacks a dye (which means most solvents) will cause discoloration IF the part is dyed. Clear anodization, being aluminum oxide, is not affected by solvents. It IS, however, removed by oven cleaner/sodium hydroxide.

For your clear/aluminum-colored parts, MEK or Acetone. Acetone will be the gentlest and MEK more harsh. Try acetone first, on a hard-to-see part of your part.

For your parts with paint or other finish, komlord has the right answer. You may not be able to remove the offending marks without a trace. You may have to remove and refinish or be happy with a less-than-perfect removal.
posted by fake at 2:23 PM on February 20

Call the manufacturer, find out what the paint is, that'll help you narrow your choices.
posted by theora55 at 2:37 PM on February 20

The chainring and seatpost are textured, so I'm not sure it'll work there, but the stem is just screenprinted on polished aluminum, which I've successfully used #0000 steel wool to remove.
posted by rhizome at 3:04 PM on February 20

Minor Update: I MEKed the non-anodized pieces (stem and seatpost). I wasn't particularly worried about those, but figured that if it was a mistake, it'd only be a $15 mistake.

Worked fantastically. Just a dab and 20 seconds of easy rubbing. (I'd show pictures, but it'd probably just be easier to imagine the above pictures with no trace of any logo.)

Gonna hold off on the anodized crankset, though, until I can weigh more options. Many thanks for all y'alls helps so far.
posted by jjjjjjjijjjjjjj at 3:15 PM on February 20

On the crankset, the logo looks like it is embossed or laser scribed into the metal. There is some kind of ridge or valley clearly visible in the m and a. So even if you got all the paint off, you'd still have the remains of a logo.

It also isn't clear from the picture whether the part has a clearcoat applied to the anodization. If there is, and the paint is applied on top of the clearcoat (which is not guaranteed, I would put it under the clearcoat if I was designing it), then something like a car detailing "clay bar" might take the logo paint off. This is a very, very fine abrasive that you rub back and forth on car paint to remove tiny bits of dirt and grit without damaging the underlying paint.
posted by gjc at 6:01 PM on February 20

Sugar cube/grains?
http://www.apartmenttherapy.com/remove-screenprinted-tech-logo-138470
posted by sebastienbailard at 8:16 PM on February 20

In my experience, standard power brake fluid (dot 3) has been the best paint remover from metal.
posted by jamjam at 10:18 PM on February 20