Old Calulator Cleaning


Like me, many of you must have struggled to clean up your old calulators with varying success and even causing some marks or damage.

However, my latest attempts have been very successful. Just try a good quality pencil erasor before anything else. I have cleaned several calculators, including biro ink stains and dirt ingrained in the rough surface of the plasic with great success.

My previous attempts have used a soft cloth with warm soapy water, which is good for many things but not biro, and often the plasic surface is left slightly more shiny from the rubbing.

I have used Ethanol for more difficult marks, which is usually ok on the good quality plastics, but be careful!

However an erasor (we call them a rubber in the UK!) seems to work best. The white ones which leave a lot of small rolls of rubber seem to work best.

Any other cleaning experiences others can share??


thanks gordon, i'll give your idea a try. i have had problems with biro marks before.

one problem i get is removing ingrained dirt from areas that shouldnt be abrased. for example, near print that would otherwise suffer or right near where there's gold or silver paint trim. soaking is what i've often done, but quite often there's still grime left. i dont use any volatile chemicals as some plastics dont like them.

on normal areas of casing, cif works wonders.



I've had good luck with Goo Gone (not Goof Off--it's a little too strong). It removes just about all grime and marks and so far hasn't removed anything that it shouldn't (like key legends). It seems to have a light oil base that won't leave plastic dried out. I've even used it on plastic LED/LCD bezels without any deleterious results.



Hi there,

I find that a half-hour in a boiling solution of chlorox and water seems to do the trick. Nice and clean.





I use silicon oil. It cleans without scratching.
Use small amount otherwise it leaves a greasy apparence.

All the best



Most markers, inks, adhesive residue, etc comes off with white gas (camping stove fuel) or a product called Oops! Oops! works a bit better becuase it contains multiple solvents. I would not recommend getting either on the keyboard area. They do not cloud or affect the display windows.

For keyboards, etc I use Windex.


I've cleaned about 100 calculators (mainly TIs and HPs), and have had very good luck with Windex. I use Q-tips (small sticks with cotton swabs at the ends) and am careful not to rub too hard to avoid scratching. I dry the surface with a soft cloth immediately after cleaning. I've had only one calculator lose any of its markings or otherwise show damage from the Windex, a TI 55 as I recall.

I also use Goo-Gone, but only for sticky substances, such as label adhesive. I've seen it cosmetically resuscitate some really grungy machines.

And of course, always test the cleaner in an out-of-the-way place on the case before applying to the more visible areas.



Thanks for all the tips, cleaning is one of those apparently simple tasks which is full of pitfalls, so I thought it would be useful to share the experiences.

Sorry about the bad spelling and typos in my first posting.

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