Spice keyboard overlay gluing (and other small repairs)

[gentzel]

I recently picked up a 34C to replace the long-gone one from my high school days. It was actually in very good physical condition with one caveat - the keyboard overlay had started to detach from the top case. It was only connected for about the top key row and bottom key row, with the overlay "arching" up in the middle.

It was fairly easy to slip a plastic dental pick through the key holes and gently pry the top and bottom loose, detaching the overlay with no damage. But how to best reattach it?




I found this thread: https://www.hpmuseum.org/forum/thread-19356.html but no good answer was posted.

So is there a glue people have found to work well for this? Obviously want something that will stick well to both types of plastic, and which will be thin enough to allow a flat application.

Thanks.

[rprosperi]

This glue works very well for jobs like this, and bonus - it's black so blends well.

Be sure both surfaces are totally clean and clear of any old residue and also be very careful to only use extremely thin beads (or even just dots) in the center of the horizontal and vertical lines, to avoid the glue squeezing out and dropping into the key well.

https://www.amazon.com/Adhesive-Precisio...B0BZ3HRDJP

Another approach is to use this thin (2mm) double-sided tape. It works really well, and can't leak, but can be frustrating to handle and apply.

https://www.amazon.com/XUMAKI-Adhesive-T...B0BWJRM9FZ

[gentzel]

Thanks Bob. I'll be giving that T-7000 a shot.

On a related note, does anyone have experience using a marker or something similar to fill in "scars" in the black coating on the plastic overlay? This one is not bad at all, but one or two spots would benefit from a touch-up. But I want to make sure it won't look worse. If nobody has advice I may test a few things out on a dead 38C that's coming (purchased for the accessories - calc has major battery damage).

[Ren]

(11-01-2024 05:56 PM)gentzel Wrote:  On a related note, does anyone have experience using a marker or something similar to fill in "scars" in the black coating on the plastic overlay? This one is not bad at all, but one or two spots would benefit from a touch-up. But I want to make sure it won't look worse. If nobody has advice I may test a few things out on a dead 38C that's coming (purchased for the accessories - calc has major battery damage).

Try black shoe polish? (Kiwi wax in a metal can)
I used it decades ago on an old bakelite radio, and it still looks good.

Ren
dona nobis pacem

[gentzel]

As mentioned above, I was planning on using a pretty badly beat up 38C as a test bed for touching up overlay repairs before doing anything on my 34C. It came in over the weekend and I saw something that's probably common knowledge around here but was new to me:



That's the 38C on the left (disassembled to attempt power ribbon cable repair) and the 34C on the right (my 33E looks the same as the 34C). Is this color difference common? Is this a deliberate decision by HP ("brown for business, black for science") or just sample variation?

[rprosperi]

There is very definitely a color scheme difference:

Business models: A lighter, chocolate brown

Scientific models: A very dark brown (often called black, but it's clearly a brown tint when holding truly black items next to it)

[gentzel]

Thanks for the info. Very interesting. Does make the idea of finding a good marker for touch-up a bit more difficult.

I'm considering picking up a set of furniture touch-up markers (such as https://www.amazon.com/dp/B0CFHGT6JK/). That would give me multiple dark brown shades to experiment with.