Restoration Help



#2

I just read about this today. IIRC, there have been inquiries about how to clean old calcs in the past. Perhaps this will help a few of you: http://retr0bright.wikispaces.com/


#3

A friend of mine used this on a junky HP21 of mine while he was doing his Vic-20 and I am impressed with the results.

My HP21 was nowhere as discoloured as his Vic-20, but the difference is significant.

I have photos if anyone is interested.


#4

Here are the images I have at present.

Tim's Vic-20 prior to Retr0brite. This had been stored by a previous owner inverted, on a desk in the sun with stuff piled on it. It looks dirty, but this is actually yellowing of the plastic.

I delivered the HP21 to Tim a couple of hours after he had started his Vic-20 case "cooking". His case is partially done here.

He tool a close-up of the HP21 to show the foam on it. We have a bloody great hole in our ozone layer here, so this probably works better/faster than for northern hemisphere people.

Tim only gave them 3 or 4 hours rather than the all day that is recommended. He used a 6% H2O2.

Here are 2 HP21s. They both looked pretty much the same colour previously. The one on the left is now almost completely un-yellow.

I might try a similar trick on the keys of this HP21. They're not that yellowed, but it would be valuable to know if the keys will be affected. This HP21 has a number of serious cosmetic problems already, so it won't be a huge loss for me if it goes pear shaped.


#5

What effect did it have on the feet?


#6

It wasn't put on the feet. The stuff is a gel or a foam and can be applied pretty much where you want to put it.

If this calculator were a good one I would have taken the other feet off, or masked them with something. (you may be able to see a masked label on the Vic-20)

Maybe I'll subject the feet (and other parts -- e.g. metal parts) to this stuff to see what happens.


Possibly Related Threads...
Thread Author Replies Views Last Post
  HP-65 Repair/Restoration (Pictures) :) Dan Lewis 8 592 01-12-2013, 12:41 AM
Last Post: Dan Lewis
  HP-01 Restoration aj04062 4 380 10-01-2012, 08:52 PM
Last Post: BobVA
  A Guide for the Restoration of Hewlett Packard Calculators Jim Johnson 8 511 04-13-2012, 03:16 AM
Last Post: Geoff Quickfall
  9100B restoration progress David Ramsey 6 405 11-27-2011, 10:33 AM
Last Post: Etienne Victoria
  HP75C Restoration (zebra connector ??) Alberto Fenini 5 296 11-01-2010, 06:47 AM
Last Post: Alberto Fenini
  HP-67 keyboard restoration Pierre Brial 4 307 04-15-2010, 11:08 PM
Last Post: Pierre Brial
  Restoration of an HP-15C Karl-Ludwig Butte 7 377 09-15-2009, 03:19 PM
Last Post: Karl-Ludwig Butte
  Voyager HP-10C restoration and bezel replacement. and the book. Geoff Quickfall 11 626 08-13-2009, 02:33 PM
Last Post: Giovanni Jimenez
  early HP-80 restoration and Tallnut HP-41C question. Geoff Quickfall 20 929 08-10-2009, 02:32 PM
Last Post: geoff quickfall
  The HP Restoration Guide, progress report Geoff Quickfall 3 233 07-05-2009, 03:44 AM
Last Post: Marcus von Cube, Germany

Forum Jump: