Display polish on vintage calculator displays?


Question: have any of you tried to remove scratches from vintage calculator displays (transparent or red) using display polishers such as the one sold under the name Displex? It's being advertised as doing wonders to the screens of mobile phones, PDAs, etc. I am just curious whether it will work on older synthetic materials too.

-- Arne



My 2 cents:
The polish works fine, only you loose the mate gloss of the display...

So at the end of the day it is a question of keeping the original little bit mate gloss and keeping it original or if loosing this and having a mirror in which you can comb you hair.

Personnaly I keep it original unless it is really badly damaged.



A very good product for LCD displays (HP 41 series, voyager series, etc...) is CrystalClear sold by Pinnacle supplies. It will make these types of displays look brand new.

Pinnacle Supplies CrystalClear


You can use the classical toothpaste with a cotton cloth or handkerchief. Regards,


On HP calculators, you can't use polish.

You have to use "reverse" polish.



On HP calculators, you can't use polish.

You have to use "reverse" polish.


Very funny! Thanks for the input :-)!



Hi Arne!

Yeah, as Albert says, toothpaste works fine as he suggested.

I use it sparingly on cotton wool to buff CDs and have done for 13 years, a few years before the CD repair "kits" came out.

If you can polish polycarbonate and perspex (and LEXAN) with
toothpaste, then i think "reverse polish" is ok to use on the calcs. I'd watch how wet you got the cotton wool,
though of course!

The key factor is the SIZE OF the PARTCLES in the paste.

Many years ago I built a 12" mirror (4 a reflecting telescope)
so I picked up info on the physics of polishing versus grinding.
In polishing, abrasive particles are fixed in a matrix which is dragged across the surface to be polished. In grinding the particles are free to roll around and do more "damage".

Cheers from Down Under,

Don W


I've used Bon-Ami cleanser successfully on a large polycarbonate thermometer lens/cover. It ground out a lot of surface checking & scratches, leaving a very slightly "fogged" finish which then was clarified with a coat of Armor-All.

But I haven't tried it on a calculator yet, so proceed with caution, and try a test application on a scrap unit before proceeding with something valuable.

Whatever you use, good luck! (& let us know how it turns out.)

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