What to do with a sticky (as in toffee) portable radio

Merry Christmas all - I have just been given for repair a small portable radio which is suffering from the sticky case syndrome, not the first I have had with this problem but something I have never been able to overcome. Previously I have associated this problem with he older models but this current example is a much more recent product. Has anyone come up with a solution to this problem?

The 'rubber/plastic has been 'reconstructed ' into another polymer , no way back.

I did once have remarkably good results with hand sanitiser, but it was probably just the alcohol content. Worth a try with IPA at your own risk.

Merry Christmas!

Rob

I've had some, generally intermittent, success by working through the gentler solvents I have about the place. Things like neat washing up liquid, isopropyl alcohol, computer screen cleaner, foaming aerosol cleaner (RS breed in my case), sticky label remover, Jizer, Gunk, et al. Apply a little at a time on small areas and rub.

If you can find the right one the results can be good for a year or so but there seems to be no lasting cure. Lots of effort for little reward. 50% success is doing well methinks.

Wear disposable gloves because a seriously wrong cleaner pick will create a super sticky gunge that seriously doesn't want to wash off your fingers.

I have the impression that regular use of foaming cleaner holds back the deterioration can prolong the life of a cleaning session. Letting finger sweat marks build up to the sticky stage seems to be a fatal mistake as the sticky seems to spread from such marks.

Clive

But why on earth one wonders should this be a problem in this day and age? Surely by now manufacturers should be aware of the problem and choose a type of plastic which is free from the problem. Is it a matter of costs perhaps, design issues or just a lack of interest? Back to the mincepies........Enjoy

Having inadvertently removed some of the matt surface layer from a Tesco Hudl tablet

[ whilst attempting to remove black marks produced by a ‘protective case’ ]

If all the gentler solvents fail … try Acetone

… this stripped the layer almost instantly, to reveal the shiny plastic beneath.

MichaelG.

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<< Proceed at your own risk >>
<< No guarantee of success is expressed or implied >>

Edited By Michael Gilligan on 25/12/2021 10:22:33

As a collector of film cameras this can be an issue with plastic bodied cameras from the 1970s onwards.

Once it has started there is no stopping it by partially removing the soft touch layer - it will always return.

The only answer seems to be removing all of the soft layer with a mild alcohol based solvent and leaving the underneath which is usually a smooth semi- gloss plastic.

Unfortunately in some cases markings and indexes are screen printed on the top surface and these have now gone too..........

Has anyone tried vinegar ?

Roy

I had a radio the same, rubber going a little sticky, I rubbed some talc over the sticky bits, cured the stickiness and also smelled nice.

David

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I think you will find that plasticisers have mostly been removed for ‘Safety’ reasons, not for cost reduction.

MichaelG.

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Ref. https://www.satra.com/spotlight/article.php?id=432

Edited By Michael Gilligan on 25/12/2021 10:52:44

Excuse the state of it

If you can't change the surface. Maybe just seal it in.

Apply a wrap. A clear vinyl wrap, or possibly just try using cling film.

The soft touch coating is probably a polyurethane which breaks down with age. This* Link * (https://patents.google.com/patent/WO2012089827A1/en) describes the problem, the polyester segment hydrolyses, the molecular weight drops and you land up with a sticky mess.

A sticky torch was sorted using a paste of bicarbonate of soda, mixed with water. Easy and very effective. I'm told using it as paste is important. I've no idea about the chemistry.

Good find, DH

MichaelG.

Acetone would seem the most obvious, and is what I've used in the past; just make sure you wipe it off quickly, so it doesn't damage the plastic underneath.

If as we believe, the material is a form of Polyurethane, then the solvent used for cleaning PU expanding foam guns would seem to be a good idea.
https://www.toolstation.com/pu-foam-cleaner/p30658

The COSHH datasheet shows this particular one to be acetone with propane & butane propellant.
https://cdn.aws.toolstation.com/items/coshh/30658.pdf

Bill

My ssmall kitchen timer has now degraded it's case, not sticky but has changed colour. I can scrape off the discoloration but there are too many small indents to do all over.

The rubbery toffee fat on the tiles behind a cooker which seems almost impossible to clean off has been cleaned off this xmas with Cif

So that might work

You've still got to find a good way to "seal" it though

The bicarbonate paste looks hopeful

Edited By Ady1 on 26/12/2021 10:04:55

I have found several Sigma lenses in my collection to have had the "soft touch" finish go sticky.. Years ago I was given a Litre sample of an Acetone replacement called Arconate PC. It is colour and oderless and did not replace the Acetone being used. I still have the sample and tried it on the lenses and it has worked by removing the soft touch coating back to a shiny surface underneath with no damage to that surface. It was a bit messy to do, using plenty of clean tissue. I have no idea if Arconate PC is still available.

Keith