Dust Cover Rejuvenation

[DrG]

Bit of an odd question....

I have some old TRS-80 dust covers (see below). Is their there a "best" way to rejuvenate them? I did some searching, but found only information on stereo dust covers (which are hard plastic).

These are soft and, while probably not as soft as when they were manufactured, are not brittle. I can unravel them from there their "stuffed in a box for 40 years form (as in the second picture)".

My inclination is simply warm soapy water and towel dry or maybe even a steaming. Like I said, bit of an odd question, but I thought I would ask.

[james_s]

They look like vinyl to me, or are they fabric?

[DrG]

They look like vinyl to me, or are they fabric?

Not fabric, allthough you can see that they are sewn. Some kind of plastic - vinyl sounds good to me, but how would I know? https://www.azom.com/article.aspx?ArticleID=987

Here is a picture (from nightfallcrew) that looks like how I remember them when new.

[james_s]

It's almost certainly vinyl. It has a fairly distinctive smell but it's difficult to describe a smell.

[DrG]

It's almost certainly vinyl. It has a fairly distinctive smell but it's difficult to describe a smell.

I think the smell of 40 years of storage has overshadow[ed] all others. I looked in some old RS catalogs and while listed, there is nada about composition. Assuming it is vinyl, what is the Rx?

I have taken one cassette cover and washed it thoroughly in warm soapy water. Afterwards, I used a healthy amount of Fantastic cleaner and washed it again. When dry, I will take a few drops of mineral oil on a paper towel and rub it into the surface.  Will post another pic in a bit.

Sound reasonable?

[DrG]

Results of soapy water, Fantastic, soapy water, mineral oil.

Before:


After:


Applied:


It would be nice if I could get them clear again, but, alas, I fear that is not to be. Still, this seems to offer an improvement.

[james_s]

It's possible the RetroBrite concoction would work to brighten them up, I don't know whether the darkening of vinyl is due to fire retardants as it is with ABS. There is only so much you can do to restore plastic, trying to reverse some of the deterioration is like trying to un-cook food.

[DrG]

I think that stuff is hydrogen peroxide based. Actually, bleach might work although I don't know what it would do to the black plastic parts...I have a whole collection of Tee shirts dotted with bleach "pinkification". What could go wrong? Hmmm

[james_s]

Yes, hydrogen peroxide and a bit of laundry boost and then some UV light. I've used it to good effect on vintage computer casings, using natural sunlight in the summer has worked best for me.

[DrG]

A very slight improvement with bleach (33%). I may play around with some peroxide, but this is probably good enough.

[ebastler]

Maybe they were not meant to be transparent, since they have printed labels stating what's inside -- in case you forget that there's a cassette recorder underneath that cover. 

[james_s]

They're similar to a lot of shower curtains, they always had a frosty appearance but they weren't yellowed.

[DrG]

I have cleaned all of them. In the end, warm soapy water and a sponge, followed by bleach and well rinsed. I could not do a whole lot about the yellowing, but they are no longer grungy and they don't smell.

I have two sets of dust covers. Only one for the cassette player but two for the monitor and two for keyboard/cpu unit. Interestingly, one set is much clearer than the other and much softer, yet they were stored in basically the same environment...for decades. Got me thinking that Radio Shack may have changed the manufacturing process at some point.

It also got me thinking that we don't use dust covers much anymore. Old farts may remember, however, typewriters regularly being covered by dust covers. In fact, you knew someone was gone for the day if you saw the dust cover on. I used to have a dust cover on my precision Sartorius scale and a few other items. Even printers used to have dust covers in the earliest days.

Maybe more hype than anything else, they were a part of the landscape which has pretty much disappeared.

[james_s]

I think it's mostly the fact that we don't have much of the sort of big chunky stationary devices that were well suited to dust covers. Clamshell laptops form their own dust cover, LCD monitors are thin enough that they lack a large horizontal surface for dust to collect on. Tablets and phones and stuff are easy to just wipe off.

[helius]

Vinyl is soft because it contains a large portion of plasticizers, usually phthalates. When those get leached out the material becomes stiffer and can crack. So absolutely avoid the use of any solvents on PVC covers. I would also avoid hydrogen peroxide. You won't be able to make it "clear" like it was originally because you can't recreate the starting mixture of resin and plasticizer. Wiping with a wet soapy rag is about all you can do for this material (bleach probably won't help either).

[SeanB]

For the vinyl after cleaning apply car dashboard protective spray, which is also sold as clear tyre shine spray. Cheap, and a good source of plasticiser for the vinyl, as you find vehicle interior plastics also use the same vinyl, which loses flexibility with age. Spray on, leave for a few minutes then wipe off, and place the cover where it will be flat and unwrinkled, for a few hours to have the placticiser soak in evenly.

I bought a 5l bottle of it around 20 years ago, and used it always on plastic vehicle trim, and this definitely has helped preserve them. Note that it is a dust magnet for a few days, till it has soaked into the vinyl.