Sticky Knobs??

[mickywillis]

COBRA MR F75-D

The volume and squelch buttons have become sticky and almost appear to be melting?
Anyone else experienced this and if so, what can be done to resolve?
Any idea how the knobs come off, do they just pull away from the front of the unit without and dismantling. Radio is about 5 years old and is kept in the main cabin, so not exposed to weather or extreme temperatures.
Radio wrks fine, so dont want to discard for this problem, but its just every time it gets turned on or volume changed/squelc altered, you get a stick residue on your fingers which isnt pleasant!

TIA.

 

[greeny]

I had the same problem on the vhf on my rib which is exposed to UV. I pulled them off, cleaned them off with cellulose thinners to remove as much of the stickiness I could. Then got some black or colour of your choice "plastic" paint in an aerosol and sprayed them. Still ok a year later. No doubt they'll need doing again sometime but got loads of paint left.
My knobs just pulled off fairly easily.
Other option is to put a piece of heatshrink over each one.

 

[penfold]

The 'soft touch' rubber coating on some things is quite short lived, this is presumably one of those. The permanent solution is to remove the coating, but this is laborious and will be fiddly if the knobs aren't easily removed; generally scraping most of it off with a plastic scraper, then a clean-up with meths, WD40, etc to finish off is the best way, you will have to experiment to find the best solvent for this. A short term solution would be some french chalk or talc on the knobs, otherwise greeny's heatshrink is a good compromise of practicality and longevity.

 

[prv]

A lot of things with these rubbery coatings go nasty eventually - but five years is really poor!

Pete

 

[William_H]

Most knobs are a push fit on to a spline. So just removed by force. However there is always a chance of wrecking something inside so be careful. Always also a chance that knob is attached with a tiny grub screw (or 2) through the side. So check closely. You may be able to find replacement knobs off old radio amp etc or buy replacement knobs from electronics supplier. ol'will

 

[mickywillis]

Thanks all, have tried contacting Cobra in the USA about the situation with my knobs, but as yet no response. If I get any luck, I will post on here. There seems to be a few of the Cobra units that share the same type, so I'm hoping that they can either supply replacements or advise on a course of action .
If not its a case of trial and error as to your suggestions and see what works.

 

[pvb]

A lot of things with these rubbery coatings go nasty eventually - but five years is really poor!

Cobra, innit?

 

[salar]

I had the same on a pair of bins. I simply removed the coating, with meths as I recall. Not all solvents remove the coating so you will need to experiment.

 

[Caraway]

Get some heat shrink of the correct size to cover the knob.

 

[Aardee]

Very common on older Italian cars, Ferrari & Maserati especially. There are lots of companies who specialise in un-stickying buttons, but it's a far from cheap process...

 

[Alex_Blackwood]

I had the same on a pair of bins. I simply removed the coating, with meths as I recall. Not all solvents remove the coating so you will need to experiment.

Surgical Spirit is a good starting point with cotton wool pads/buds. I did a "PURE" DAB radio with that. Retained all the logos etc. Nice shiny plastic underneath.