How common are bleached dyesubs?

Dikkus

18 Jun 2020, 06:49

Having seen more than a few very old IBM keyboards now, I just came across a bleached "A" key on my recently acquired '86 Model M. It got me looking around on the web for other people with bleached dyesubs, merely out of curiosity. I've seen some people get bleached dyesubs within a few months, others it seems to take decades. Is there any hard science on what causes this and why it seems to be so sporadic? How many of your boards have bleached dyesubs?

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Weezer

18 Jun 2020, 07:08

What do you mean by bleached?

xxhellfirexx

18 Jun 2020, 07:18

Weezer wrote:
18 Jun 2020, 07:08
What do you mean by bleached?
I think what he means is that the dyesub legends fades so the edges of the lettering is no longer sharp.

I believe there was some discussion about how some NOS IBM keyboards have faded legends due to being stored in a warmer environment.

Dikkus

18 Jun 2020, 07:29

Apologies if the terminology is incorrect, that's just what I've seen it referred to over the internet.
Here's an example, apparently it only took 2 weeks for this guy to have defective dyesubs:
Image
And here's a picture from my "bleached" A keycap next a normal S keycap:
Image
Notice the color fringing? It's a bit red around the edges and looks fuzzier.

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Weezer

18 Jun 2020, 08:46

You're good. Your terminology is fine, I just wanted to clarify because there are a few things that can go wrong with Model M key caps.

In the images linked, where the color bleeds away into the surrounding areas, that's generally caused by heat, or a dye sub that was done improperly. Not enough pressure being applied during the heating process, moisture exposure during the process, or not enough heat, are common culprits. Heat/UV rays/rubbing on the ink after the dye sub is finished will cause the ink to bleed, smear around and wear off in a situation where the ink isn't properly bonded to the material. I think that's what's going on in the first image.

In properly done dye subs extreme heat/UV exposure will also cause the same thing to happen. This happened to my Model M in the other thread, which I had in my car. That would be my best guess for what's going on with your A key, or the A key may be a replacement from a keyboard that was left in the heat or a later production Model M, that someone has popped on there since the key caps often fall off and get lost. Later Model Ms tend to have more cheaply done dye sublimations as IBM and later Lexmark continuously cut production costs. Model Fs generally have the best sublimations.

If you're interested in learning more about dye sublimation, there are several articles online as well, which describe the printing process in a broad scope. I'm by no means an expert on the matter.

As for how frequently this can happen- I can't speak to that on a by-the-numbers basis, but I can say that all of my IBM keyboards haven't developed any bleaching like on your A cap bar the one I left in the car for a couple days. My anecdotal guess is that the bleaching on most Model Ms comes from being stored for long periods in hot attics or warehouses after companies and consumers downgraded to the rubber dome menace. I didn't know that heat could be as destructive as it is to these keyboards until I did some research this week and I suspect many people are of the same mindset, especially with the reputation Model Ms have for being tanks.

There may be more factors to what's going on that I'm either naive to or are just hard to pin down. Most these keyboards are Triassic period fossils that have had long and hard lives as work horses so it can be hard to say where along the line damage occurred.

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Chyros

18 Jun 2020, 09:20

Dyesubs can what I call "smudge" and "bleach". With the former, the edges become blurred and the legend loses its sharp edges. With the latter, the colour simply fades; in the case of IBMs, usually into a purplish colour. This isn't (necessarily) paired with smudging.

4_404

18 Jun 2020, 10:24

Speaking of purplish colour, I have a couple of NMB boards with space invaders and dye subs that were outside for an extended period. Some of the lettering has almost disappeared, and what is left is mostly a light purple. Some caps from an RT8875 included for comparison.
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Weezer

19 Jun 2020, 04:35


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TheInverseKey

19 Jun 2020, 05:35

4_404 wrote:
18 Jun 2020, 10:24
Speaking of purplish colour, I have a couple of NMB boards with space invaders and dye subs that were outside for an extended period. Some of the lettering has almost disappeared, and what is left is mostly a light purple. Some caps from an RT8875 included for comparison.
I have some caps like this on my ICL DRS keyboard manufactured by NMB. Not that common but it does happen from time to time.

Dikkus

19 Jun 2020, 06:07

Wow. That price and that condition, and the seller says it's in "great shape." :lol:

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hellothere

19 Jun 2020, 18:36

Remember: you have to clean the keys yourself. Don't wanna smudge them!

Somewhat adjacent to this thread, I ordered a set of 122 keycaps from Unicomp for my 1980s Model M. They do have all the terminal legends, etc. I don't remember if they have the blue and/or or green legends on the front of some of the caps. They're one-piece caps, though.

EnthusiastDude

20 Jun 2020, 12:36

Dyesubs smudging and bleaching is a really weird thing, it isn't really exclusive to some keyboards and it isn't on all old keyboards either. I have a Model F XT in almost NOS condition, which has really smudged legends, so it can't be due to UV exposure or use as well.

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