Cleaning Sticky Residue and Rubbery Paint Off Plastic

Danger – this is a potentially dangerous cleaning hack, but it works. If  you have a sticky, greasy material that’s like the flypaper schmutz on your plastic products, and it doesn’t seem to come off with soap and water, try this crazy technique.  Be careful, because it can burn your hands.

I’m assuming you know what flypaper is, but if you don’t, you should.

Flypaper Digression

It’s a strip of thick paper that’s coated with an adhesive, usually rosin-based, that attracts flies, and adheres them to the tape.  Over time, the tape fills up with flies, killing them all.  It is generally safe, though some flypapers contain a poison.

The adhesive is a greasy material that’s a mixture of rosin, which is made from pine sap, rubber, and oils.  The oils melt the rosin and rubber, creating a sticky mess.

Flypaper is a healthier alternative to aerosol sprays to keep down the flying insect population.

Back to the Gunk

An adhesive similar to flypaper forms when you combine oil with a thicker material, like paint. Many products today are coated with a rubber paint, to give them a “soft” texture.

People generally think this material is a hard rubber, like tire rubber, but it’s really just plastic with a thin coating of rubber paint that makes it feel like a hard rubber object.

All rubbers are actually liquids – but they are temporarily made hard by a chemical process called vulcanization.  However, as rubber is exposed to air and light, it degrades, returning to a softer, liquid state.

As the rubber degrades and becomes sticky (I think it’s oxidation), if there’s some oil around, mixes with the oil. Some personal electronics, like cell phones, are filled with oil from our faces.

You cannot easily wash off this gunk with soap and water, because, while the soap can emulsify the gunk, there’s so much gunk, and it’s so tenacious, that it won’t come off.  Scrubbing just smears the gunk around, turning it even uglier.

You can make some headway by scrubbing it with some baking soda on an old toothbrush.  If that works, great!  You have solved your problem.

I’ve also read that Goop or Gojo hand cleaner, which is made with petroleum, can melt this gunk.

Alcohol reportedly works, as well.

However, if that doesn’t work, you need to bring out the “big guns.”

Lye, or oven cleaner (the same thing).

Here’s How to Use Lye to Clean off Greasy Gunk

Work in your bathroom, and open the window and run the fan for maximum ventilation.  Drink a couple cups of water to moisten yourself.

Put on some gloves, so you don’t burn your hands.

Try and wash the gunk with an old toothbrush.  That should put some of the sticky residue onto the toothbrush, and you can use this as a test sample.

Spray a tiny amount of oven cleaner, like a 1-inch circle, into your washbasin.  Rub the dirty toothbrush into the cleaner, and see if the stuff mixes with the gunk, and cleans off the toothbrush.  If it works, the lye will work on your object.

Note: lye eats away at aluminum, so you can’t use it on aluminium.

Dab your toothbrush into the lye, and then gently rub the foamy lye into the gunk on your object.  Rub it around a few seconds, then wipe it off with a wet cloth.

Repeat around the object. Then rinse off the wet cloth, and wipe the object down again.

There may be a little gunk left on the object, but you should be able to clean this off with a little soap.

Rinse out your wash basin as well. You want to flush all the lye down the drain.

What’s happening?  Lye converts greases into soaps.

Everyone who makes soap knows: fat + lye = soap.

It’s a process called “saponification”.  Lye reacts with the fatty acids to produce a salt, called soap.

The soap, in turn, can emulsify grease, so it can be washed away.

All  you’re doing is making a little soap from the greases, and that releases the gunk.

Oven cleaner is a lye mixed with a little detergent and a foaming carrier.  So it’s not as harsh as pure lye – but inhaling the gas will burn your lungs. It also has detergents to help with cleaning.  The canned stuff can also be bought cheaply at a dollar store, and you can dispense tiny amounts

Despite all these warnings, and the fact that lye can kill you, it’s not a terrible chemical. If you use little of it, the residual lye will react with greases in the pipes, before it gets too far into the sewer system.

Because it’s so harsh, people tend to use it sparingly.  Contrast this with the overuse of plain old detergents, like dishwashing detergent, or clothes washing detergents, both of which have environmental effects.

 

Author: John

I can be reached at johnk@riceball.com.

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