Disintigrating 41C soft case



A while back I acquired a 41C+card reader, with a soft vinyl case. I recently pulled it out, and was surprised to find that the reference cards (and to a lesser extent, the calc) were covered by a fine, sticky black dust. This is apparently from disintigrating foam in the case lining, and it's hard to wash off. Has anybody else had a similar experience? How hard is it to find replacement cases?




I experienced the same with my HP71´s softcase. I have washed it and now all seems to be ok. But I think within the next few months the inner nylon will have disappeared completely...

Best regards



I've experienced the exact same problem with two HP-71B soft cases: lots of fine, black dust, that was very difficult
to remove from the LCD display, keys, ports, etc.

It seems to me that after 15-20 years they disintegrate
spontaneously, as the cases are brand new on the outside.
I've tried to remove all the dust but to no avail. The
"solution" is to keep the 71B themselves inside a thin, sealed plastic bag, then that plastic bag into the case. This
means everytime I use them I must use a new plastic bag,
but at least it keeps the potentially dangerous black
powder at bay, while protecting the machines inside their
proper cases.

As for finding replacement cases, it isn't hard, only
expensive, and probably pointless since the replacements,
if original, are likely to disintegrate as well.


I've also experience the same problem with a case for a 41C. It' s peculiar that it happens to some cases and not others the same age. It might have something to do with where you store the case and the surrounding environment. If the storage climate surrounding the case is humid and damp, this problem is more likely to occur. It's advisable to maintain your collection in a dry and moderate temperature environment. These cases are very hard to find, so it's best to try to fix the problem.

To correct this problem, I cut out the nylon lining completely around the edge. This lining protects the spongy glue based material. Once I cut the nylon lining around the entire perimeter of the case, I use a vacuum cleaner's main hose to SCRAPPE out the spongy glue based material completely. It's best to turn the case inside out to accomplish this task. Once you have removed all of the gook, take a hair dryer, HOT, and solidify the remaining material by drying it for at least 15 minutes.

Hope this helps


I have found that the 41 with card reader and the 48 are the same size. So any case that fits the 48 will fit the 41 with cardreader. You might check procalc for a 48 replacement case.


Just take the case and toss it in the wasing machine. Let air dry with something proping open the mouth. Might have to repeat. It seems the sub-lining is what decomposes.


I forgot to mention, I have washed MANY HP41 cases and spice cases over the years. The grunge has never reappeared in any of them. Some REALLY grungy spice cases in particular come out of the washing machine looking like new. It seems only cases from one source seem to get the grunge. I guess about 1 in 10 HP41 cases and 1 in 5 spice cases have the problem.


Washing worked well--thanks for the suggestion. The foam residue is gone, and it seems safe for holding the calculator. The cosmetic result is great. I suppose, however, that the case offers less protection against trauma than it did before all the foam disintegrated. Essentially, there's no padding. Ah, well.


Most of the cases did not have any foam padding anyway. I think what decomposed was some kind of backing material.

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