Fixing the bezel on a 10C

Hi all, I have a 10C that is in perfect condition except for the bezel. It is not scratched, but has imperfections in the form of wavy lines - you can see in this photo: HP10C

Does anyone know if this is fixable? I am nervous to try to 'polish' the bezel in case it wrecks it. Is there a resin layer over the bezel? Thanks in advance, Keith


It looks like this has been caused by gluish material from the inner part of the vinyl case. Perhaps the calculator was kept inside the case for too long. I have an HP-11C with this kind of imperfection near the logo, to a lesser extent however.

Yes, the bezel is coated with kind of a varnish. Polishing the bezel is not a good idea, unless you have a technique to restore it to its original appearance. I think Geoff Quickfall might help on this. The bezel of the HP-15C in the picture has been polished, but no resin layer has been applied.




as Gerson says, it could be a glue residue. however, do you feel it is like an etching down into the surface of the aluminium?

i have seen aluminium escutcheons that are coated with varnish, where moisture has got below the varnish and corroded lines in the aluminium that look very much like what is on your 10C.

if it is just glue, one good 'universal' solvent that can be used is eucalyptus oil, or better still a product called "de-solv-it" (based on oil extracted from orange peel). with either: apply to glue (or to surface of a label to be removed), leave for 10-15 minutes, and then peel off label or wipe away remains of the glue.

any chance you could post a much closer-up photo?


There are imperfections in the opposite side as well:


i'm afraid that does look like corrosion to me. i have no good solution that is simple apart from keeping the calculator is a very dry place to slow down any progress as much as possible. a complex solution would be to remove the escutcheon, clean back to bare metal, then re-varnish, but that is quite a bit of work and very hard to obtain the original finish.

or get a nice HP employee to send you a spare one (assuming the modern 10 series calculators are exactly the same dimensions, with badge in exactly the same place).


Thought i would offer a tip i learned from another collecting hobby. In knife collecting you never long term store a knife in a leather sheath. A sock or just storing in dry place uncovered seems to work best. Leather products and their treatments are notorious for causing damage.


Thanks for your tip, Ethan. I fear Robert is right about corrosion caused by moisture. Though I haven't noticed the stains haven't increased since I purchased that 11C four years ago, I have noticed a tiny speck on the bezel of my old 3-battery 12C which was not there before. The calculators have been kept in a clothes closet facing a north-oriented wall. Time to look for another place to keep them...

Edited: 3 Sept 2011, 10:08 p.m.


I had this problem with a slide rule. Most of the old K&E came in green or orange leather cases. I left a slide rule in the leather case for years, and the metal band around the runner rusted out completely.

Keep your slide rules out of the leather case!


Thanks everyone. I suspect it is mild corrosion under the top coat. I purchased it for a nice price on TAS earlier this year in this condition, so it was already there. It hasn't got any worse since i've had it (I keep all my collection in a cool, dry place). I will take a closer photo and post it in the next day or so. Cheers, Keith

Possibly Related Threads…
Thread Author Replies Views Last Post
  HP-10C Series Family Photo Max Stone 5 2,105 10-24-2013, 10:31 PM
Last Post: Eddie W. Shore
  10C, 11C, 12C logos on The Auction Site Peter Murphy (Livermore) 0 938 06-14-2013, 11:24 PM
Last Post: Peter Murphy (Livermore)
  Glue for HP42S bezel Basil 0 802 08-08-2012, 12:23 PM
Last Post: Basil
  Hp 12C replacement bezel James Nelis 0 841 04-06-2012, 06:37 AM
Last Post: James Nelis
  Bezel exchange hp 12C Diehl-Peshkur 2 1,058 05-16-2011, 11:37 AM
Last Post: Diehl-Peshkur
  Light Scratches on 12c Bezel - Steel Wool? Matt_12c 4 1,630 04-10-2011, 01:36 PM
Last Post: Matt_12c
  A Most Unusual Number, on the 10c/11c/12c/15c Katie Wasserman 8 2,243 07-15-2010, 03:53 AM
Last Post: Katie Wasserman
  removing alluminium bezel (was restoring an HP11C) Alberto Fenini 2 1,160 05-24-2010, 04:21 PM
Last Post: Alberto Fenini
  10C batteries John Mosand 0 683 10-12-2009, 06:06 AM
Last Post: John Mosand
  fixing my newly acquired HP-48sx Hugh Evans 0 673 08-25-2009, 01:07 AM
Last Post: Hugh Evans

Forum Jump: