Deteriorating pouch (case)



I have two cases for Spice calculators and one for my HP-41CV. All three have the problem that the inner black synthetic material is deteriorating in a way that it crumbles into tiny black crumbs.
The HP-41CV I removed from the pouch had these crumbs all over the keyboard. I used a vacuum cleaner to get rid of them.

Is this a normal process of such a pouch?

Is there anything I can do to fix it?
All I can think of is to throw them away.

Any ideas?



Edited: 25 Nov 2010, 4:06 p.m.


The same thing happened to my 71B case but not my 41CV case (which is older). Both were stored in the same environment. Those crumbs also stuck to the quick ref guides I had in the 71 case. They cleaned off with a damp paper towel thankfully.

I can't bring myself to throw out the case but I don't use it anymore.

Edited: 25 Nov 2010, 4:20 p.m.


It's a common problem. You can put the HP-71B inside a plastic bag inside the crumbly case.

-- KS


Don't throw them away. I (or more exactly, my wife) put it into the washing machine; use a gentle washing program (30/40°). This worked well for many HP-41 cases.

There seem to be different HP-41 cases, some of them show this deterioration, others not.

Hope it helps,


My HP-71B case had the same problem (sticky and greasy black particles). I turned it inside out and drowned it a bucket with water, powder-soap and a fabric whitener (Vanish 02). I waited about thirty minutes then washed it and rinsed it a couple of times. After dried up, it felt like new. I still don't know what did the trick (the whitener, the soap or both).

Hope this helps,



After washing is it possible that the problem occurs again some months/years later?

I guess I have to find out.



Mine is still perfect after four years. Whatever was that, it simply has vanished away :-)




Mine just came out of the wash. Will report back when it dries :)


It came out of the wash and dried and looks almost new. The inside feels a bit thinner but no more flakes!


I will wash mine too.



I don't have any older HP's with the style of case you refer to, but I assume this is a foam rubber lining that is deteriorating.

This seems to be a common problem with foam on old equipment. I have had this happen with many camera-related cases from the 1970's and 80's. Not only foam, but the leatherette cases seem to get to a certain age, and then crack and crumble, or turn gooey, like the infamous card reader rollers.

I have often wondered if this is environment-related or just age.

Interestingly, just recently the headliner in my (Dodge) truck began to droop. I found there was a thin foam pad above the fabric, and it was crumbling. Now the truck is only six years old.

When I took it to the auto trim shop, the guy indicated it was a common problem. He said the factory foam "has oil in it," but his replacement material does not.


Yep, same problem in my 74 5spd Celica (my high school car purchased in 76) head liner. New closed cell foam has been applied and it looks as original.

Ditto on the pouches also. I hand wash mine in the kitchen sink with mild liquid dish detergent and they turn out fine. At worst the foam disappears. At least they are still good for storage!

Cheers, Geoff

Edited: 26 Nov 2010, 2:39 a.m.


I think those wheels are a bit too small for your car =)

Good luck on that project!


Don't worry, that's the typical reaction of older cars having experienced a flooding -- eeek! Their wheels shrink and they are like getting on their toes till it's all really dry around them -- you can still see the traces of water on that picture. Don't worry ;-)


those are all season radials!!!!



those are all season radials

... for easy city maneuvering in southern California. Take care, however, in SFO - even that little wooden brick won't be a big help parking there d;-)

Edited: 27 Nov 2010, 12:47 a.m.


I've had good luck turning them inside out and washing them in the laundry, then letting them air dry. I've tried washing in the sink, but it doesn't seem to get all of the particles out nearly as well. The cases end up in surprisingly good shape after a good cycle through the wash!

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