|Bezel restoration in place with pictures and glimpse of what the book includes:|
Message #10 Posted by Geoff Quickfall on 12 Aug 2009, 5:48 p.m.,
in response to message #9 by Giovanni Jimenez
Any one wondering what will be in the book can look forward to a variety of techniques for restoring the calculator from electronics to physical shape. Here are some steps found in the Voyager section (in point form here, not quite as in depth) with accompanying pictures. The text will have many more intermediary photos with accompanying explanations.
I have designed the book to help the (like me) non technically oriented to restore the basic problems in mechanical design as well as the most frequent, fixable electronic problems (LED block replacement, contact cleaning, substitutes in foam inserts and etc.)
In a nutshell the book is:
1. about 250 pages
2. over 300 photo illustrations with accompanying text for all
thirteen calculator families up to and including the
3. 130 pages completed so far including chapter 8, the HP-41C
a. HP halfnut restoration
b. HP fullnut restoration
c. Rechargeable battery pack reconditioning
d. Memory enhancement (2X-memory)
4. Hoping to be done for HCC2009 in October but it still has
to be peer reviewed by the committee.
5. Expecting to be on demand publishing but I should have some
copies made up prior to that (donít know the cost yet).
Thanks for the order, now to complete the book (half way and counting).
There are two methods to restoring the Bezel.
"REPLACING" OR "RESTORING while in place."
I am going to consider that the bezel is scratched and not dented, i.e. you would rather remove the scratches and refinish with a brushed finish with the bezel in place.
1 cover the clear plastic lens with a non sticky piece of paper
which covers the lens only and not the two depressed bezel
pieces at either end. Any application of a sticky mask to the
lens and subsequent removal may only serve to remove part of the
anti reflective coating. Hold this in place with a piece of
masking tape long enough to attach to the two depressed bezel
pieces at either end.
2 if the HP15C badge is metal (pre 1982?) then mask it, other wise
remove it by applying heat to the badge with a hair dryer then
gently prying it off.
3 mask the entire calculator seen in the picture below.
4 once masked, secure a piece of 400 grit wet dry sand paper,
green plastic pot scrubber (scotch brite), alcohol and gloss
lacquer spray can.
5 using a parallel motion, be as accurate as possible, use a
stroking motion with the sand paper parallel to the
longitudinal axis of the calculator until the old lacquer is
completely removed as well as the scratches.
6 to remove the harshness of the finish, repeat step 5 with the
plastic pot scrubber material.
7 clean with alcohol to remove any oily residue and remask the
lens if required.
8 spray the lacquer according to the manufactures requirements,
many light coats as opposed to a runny heavy coat.
9 let dry overnight.
10 heat the masking tape until warm to the touch to soften the
adhesive prior to removing the tape. This IS IMPORTANT!!!!
The heat softens the adhesive and when removing from the back
of the calculator it, when warm, will release without removing
any labelling on the instructions.
11 Reglue the badge in place with contact cement.
Removing the bezel is a long process that must be carefully done with precautions. It requires lots of heat so the LCD must be removed in the early two piece versions (HP-15 I don't think was ever the two piece PCA) or protection of the LCD panel with cloth. You will have to wait for the book for that! If the bezel is just scratched and not dented then refinish the bezel in place.
HP-15C MASKED FOR REFINISHING AND LACQUERING IN PLACE WITH
NEW OLD STOCK METAL BADGE MASKED:
HP-15C WITH REFINISHED BEZEL WHILE BEZEL WAS IN PLACE
(dark LCD lens due to polarizer on camera interfering with
polarizer on LCD panel):
HP-10C BEZEL BEFORE BEZEL REMOVAL PICTURING THE THREE DENTS
ON THE RIGHT SIDE WHICH COULD NOT BE SANDED OUT:
HP-10C BEZEL REPLACED WITH AN HP-11C DONOR THAT WAS
REFINISHED AFTER REMOVING IT:
BEFORE AND AFTER BEZEL REPLACEMENT ON THE HP-10C:
Hope this helps!
Edited: 12 Aug 2009, 6:03 p.m.