OK, I have this Staedtler 475, not a fancy pen but I have a fondness for Staedtler, and it had a little sticker goo on the barrel. I used just the tiniest amount of rubbing alcohol to remove the goo. Next thing I know there is a crack in the barrel seeping ink! What happened?!?!

Soooo, I don't know what came first, is this a known incompatibility of the old Staedtler plastic and did my application cause the crack to occur OR did I simply not notice the crack before I removed the goo? In my defense I must note that the crack and where I applied the rubbing alcohol are two very different places, and the pen was in a rather soft leather carrier so it could have impacted something earlier...

Either way I've lost a nice little school pen but I'd like to know if I'm an idiot for trying to remove goo, or if I can blame it on thin plastic of the barrel. Please advise, and receive such thanks as befits a king's remembrance. (yea, I often use Shakespeare to draw attention away from my boneheadedness)

Maybe alcohol can act as a solvent to certain plastics?

It most certainly can!

Remove sticky residue with oil-based products - baby oil, citrus oil or even cooking oil.

Please do not use isopropyl / rubbing alcohol / acetone / methylated spirits etc near pens. Not even a tiny amount! Yes some plastics will be fine - but some will not survive. Don't risk it.

If the alcohol was dissolving the plastic of your pen, you would have noticed an area of softened, gooey plastic.

I would think that the crack was there before, and the stress on the pen from the rubbing just opened it up completely.

This is a known issue with a number of German pens, including Pelikans. Direct exposure of the barrel material to alcohol can cause near-immediate development of multiple stress cracks. This happens very quickly indeed -- before the alcohol even causes any perceptible softening of the surface.

Hi,

This also happens to Pilot カスタム (Custom) pens. The pen practically disintegrates or breaks aparts. Modern Pelikans also get damaged by alcohol, especially the Tradition and Souverän lines. In this case, I think the pen dissolves.

Dillon

So what polymer are they made from? IPA isn't a great solvent for polymers--if there is crazing that occurs upon exposure to IPA, it could be leaching out a placticizer. Still going to cause damage that can't really be fixed but I'm curious now.

A curious Todd

I am older, sadder but wiser and I thank you for this enlightenment. Like Todd, the mechanism of this reaction escapes me and I would have never expected it. I guess I'm lucky that this happened with my least expensive pen but...

Anyway, thank you all. I'll see what I can do about the king's remembrance stuff.

Yah I'm in the same boat as you. I didn't think isopropyl alcohol was a very good solvent for plastics. Also, those pen plastics aren't porus so only the surface should be melted/damaged. The cracking is kinda surprising to me. Can someone from materials chime in here?

I guess you really do treat it like your baby.

Hi,

Yeah, actually, it probably was not dissolving, now that you mention it. it does cause severe clouding of the plastic, and the parts that it touches, it appears to weld together.

Dillon

Yes, but clouding does not occur immediately. In my recent experience (sigh) what I saw first was the weeping hairline crack parallel to the barrel. Once I got it empty I noticed the clear ink view windows had hairline cracks that seemed to radiate from a single location. That's why I was so confused at first, the cracks in the clear view windows kinda looked like an impact. Now, in 20-20 hindsight, I realize the clear windows are under the cap and any blow would have been evident on the cap. (duh) The clouding only started appearing in the last 24 hours or so, especially evident in the threads on the barrel that engage the cap where the liquid collected cause the threads blocked its flow.

Just be thankful you didn't ruin a really nice pen, like a Pilot Custom 823 clear demonstrator. It literally took seconds for the nearly brand new pen to fall apart, from the use of 50/50 water & denatured alcohol. I was merely trying to rinse out some (suspected staining) Waterman Purple ink. All that was salvageable was the nib. Trying to use it on another pen.

Hmm. Just thought of a warning I once received from an office machine repair technician, to avoid alcohol for cleaning certain rubber working parts, because it could cause cracking. (The technician recommended Simple Green instead.) Might be the same phenomenon.

On the other hand, I've experimented with a DROP OR TWO of 190-proof isopropanol in an ENTIRE BOTTLE of Sheaffer black, to improve wetting and speed drying; the results were debatable, but it seems to have had no ill effect on my Pelikan M150.