EEVblog #560 - How To Remove Sticker Residue On Test Equipment

[G7PSK]

A lot of labels can be peeled off complete with the glue if you warm them up first with a hair dryer.

[marmad]

You can probably save it.  Go back and remove the residue (I use Bestine Thinner, which is just heptane), then polish it up with Novus plastic polish (or automotive headlight polish).

I've never tried heptane - using instead 99% n-paraffin (which, in the EU, is also straight-chain alkanes, C10-13). Does heptane work as well as (or better than) n-paraffin for taking virtually anything off plastic (residue, paint, magic marker, etc) without damaging it?

I'm refurbishing old equipment, so I'm always on the lookout for the best solvent for removing years-old crap without damaging plastic - so I'm wondering if I should give heptane a try. I've read that lower carbon number n-paraffins are usually the best solvents, so heptane is perhaps the lowest (that's still considered reasonably safe).

[grumpydoc]

You can probably save it.  Go back and remove the residue (I use Bestine Thinner, which is just heptane), then polish it up with Novus plastic polish (or automotive headlight polish).

Fortunately I quickly realised and had only completely removed the paint from the very edge of the case - which is hidden by the front panel.

[reagle]

What a timely post- I am working on my own pile of auction loot
Among the goodies is a bunch of of Fluke 70 and 73s with broken calibration stickers along the seams. Somehow Fluke thought that requiring recalibration every time user changes a battery is a good idea. So now I am left with half-circles made of a plastic that breaks the moment you pull on it. Any suggestions on how to deal with that? You can see how they've removed them in the past- by taking chunks of cases with them..
Another menace is user initials in permanent marker. Using eraser and 90% alcohol that came off the front that's a label overlay, but it's a different story on a plastic

[Dave]

Never thought of using a rubber to get rid of the sticky residue. I always used IPA for cleaning everything. I guess I'll have to buy some more used equipment to test your method.

In case you are wondering, yes, I intentionally wrote that first sentence like that. *giggle*

[edavid]

You can probably save it.  Go back and remove the residue (I use Bestine Thinner, which is just heptane), then polish it up with Novus plastic polish (or automotive headlight polish).

I've never tried heptane - using instead 99% n-paraffin (which, in the EU, is also straight-chain alkanes, C10-13). Does heptane work as well as (or better than) n-paraffin for taking virtually anything off plastic (residue, paint, magic marker, etc) without damaging it?

I'm refurbishing old equipment, so I'm always on the lookout for the best solvent for removing years-old crap without damaging plastic - so I'm wondering if I should give heptane a try. I've read that lower carbon number n-paraffins are usually the best solvents, so heptane is perhaps the lowest (that's still considered reasonably safe).

I've never tried n-paraffin... is there a commercial name for it in the US?

Anyway, heptane won't remove paint or marker, but it's great for softening adhesive.  You can use it to remove one label that's on top of another label without damaging either one.  Cal stickers, no problem...

[Bored@Work]

So now I am left with half-circles made of a plastic that breaks the moment you pull on it. Any suggestions on how to deal with that? You can see how they've removed them in the past- by taking chunks of cases with them..

Heat and a cooktop scraper.

[grumpydoc]

So now I am left with half-circles made of a plastic that breaks the moment you pull on it. Any suggestions on how to deal with that?

These are a pain to  get off. As you say they are designed to break apart so you can't just pull them off.

In theory the way to deal with them is to use something thin, slid between the label and the surface it is stuck to and then just slowly work at it until all is removed. The difficulty is finding something strong enough to actually be able to separate the adhesive whilst not scratching the plastic. I've decided a fingernail is just about ideal but I do have fairly strong nails so it might not work for everyone.

[TheWelly888]

At work I often need to clean off sticky label residue on medical equipment (for better appearance in the clinics/wards!) and usually use 70% IPA saturated cloths or detergent. But the other day I tried the plastic rubber on one of those cal void labels that leaves patterned sticky mess and it works!

Thanks for that tip! 

[marmad]

I've never tried n-paraffin... is there a commercial name for it in the US?

Well, n-paraffin can refer to any straight-chain alkane (a saturated hydrocarbon where the carbon atoms are joined in a linear, snake-like structure with the general formula CnH2n+2). Heptane is one of those n-alkanes (7 carbon atoms = C7H16), and the n-Paraffin EU 'product' I'm taking about (CAS nr. 93924-07-3) is between 10 and 13 linear carbon atoms, but it mostly consists of C12H26, which is Dodecane (also known as dihexyl, bihexyl, adakane 12 or duodecane).

Anyway, heptane won't remove paint or marker, but it's great for softening adhesive.  You can use it to remove one label that's on top of another label without damaging either one.  Cal stickers, no problem...

Yes - other chemicals/techniques that people have mentioned here (Benzine, eucalyptus oil, citrus oils, IPA, heat, etc, etc) are poor compared to the middle n-alkanes (C5-C15) for plastic. Once you've tried n-paraffin (and I imagine heptane is the same) to clean/remove things from plastic, you'll never use that other stuff again.

I refurbish vintage analog synthesizers, and I've used n-paraffin to take off any and all kinds of adhesive/labels in seconds - as well as paint, magic marker, etc. from keyboards and dials - or from virtually any type of older or newer plastic.

[IanB]

The miracle cleaning liquids commonly found in the USA like Goo Gone or Goof Off consist primarily of light petroleum distillates, essentially the same thing as the C7 to C13 alkanes mentioned in this thread. In the old days we might have used petrol/gasoline for this purpose (much cheaper), but these days car fuel contains all sorts of nasty additives and is probably not the best choice as a delicate cleaning solvent. Great for bicycle chains, less good for plastic lenses.

White spirit (clear mineral spirit) is a similar solvent. If you started with white spirit and added a bit of citrus oil you would probably recreate Goo Gone.

[marmad]

The miracle cleaning liquids commonly found in the USA like Goo Gone or Goof Off consist primarily of light petroleum distillates, essentially the same thing as the C7 to C13 alkanes mentioned in this thread. In the old days we might have used petrol/gasoline for this purpose (much cheaper), but these days car fuel contains all sorts of nasty additives and is probably not the best choice as a delicate cleaning solvent. Great for bicycle chains, less good for plastic lenses.

White spirit (clear mineral spirit) is a similar solvent. If you started with white spirit and added a bit of citrus oil you would probably recreate Goo Gone.

Goo Gone is 90% to 95% CAS nr. 64742-47-8 - which seems to consist of both iso and n-alkanes C11-C16 - so not like the pure n-alkanes I mentioned. Goo Gone seems to be a general, multi-surface cleaner - while what I wrote about is not general purpose - but instead, the best thing for specifically plastics (and certainly nothing like gasoline - which would be terrible on some plastics). The n-alkanes make poor fuels - but great solvents, while isoalkanes tend to make better fuels.

White spirit (clear mineral spirit) is a similar solvent. If you started with white spirit and added a bit of citrus oil you would probably recreate Goo Gone.

White spirit (assuming you mean petroleum spirits) are alicyclic hydrocarbons in the C7-C12 range. You might have a hugely different result using the two chemicals (White spirit/Goo Gone) on the same surface.

[GBoos]

You can use any vegetable oil you find in your kitchen, it will do no damage to any plastic.
I use it every time I need to remove stickers from any surface.