I'm currently doing a resto on a 1960s valve transceiver.

The top of the chassis was quite dusty but the dust was stuck on with a sticky film of something or other that I haven't encountered before.

It's not like nicotine, nor like the usual stearate problem you get with radios that have spent their life in the kitchen. The rest of the set, including the underside of the steel chassis, is very clean and dry; it's just the top of the chassis and the tops of switches and transformers that have this tacky substance on them.

It came off fairly easy with metho.

Got me wondering what it is and how it got there.

Eeeww, strange sticky substance? You might be better off not knowing. Hairspray if it was near a dressing table maybe?

Dunno about hairspray?

I expect it would have spent its life in a radio shack.

What's got me tricked is how the rest of the set is clean as a whistle.

Only thing I can think of is mouse wee. It's not as thick and gooey as wee from rats and possums and if there's holes in the top of the cabinet it could enter through these.

Nah, it's not mouse urine. I've struck that before with an old Hammond organ I restored. After disinfecting the cabinet I had to leave it in the garage for 6 months until neither I nor the cat could detect the smell any longer

Not cockroach pee either. If you've ever been around any electrical/electronic equipment used in food retailing you'd be very familiar with that pong.

Whatever this (odorless) stuff was, it evenly covered every flat surface that faced upwards. Starting to wonder if somebody had sprayed the unit with some sort of preservative at some stage many moons ago.

It could of been sitting in or near a kitchen for many years. The owner was probably doing a good job of wiping the exterior of the radio but vaporized oils/fats will get into all sorts of places such as the inside of a radio and settle on the flat surfaces.

Cheers
Peter

If it was in a shed and stuff can run into it, Aviation gasket cement is brown & sticky & those bottles do tend to leak if tipped over, or it was in a tube.

Mouse doo is not that soluble in metho. The best thing to remove it is aluminium wheel cleaner, or (Pool) Soda Ash (Soduium Carbonate ... not Sodium Bi-Carbonate) + brush

Being a water based system you need to be extremely careful where you use it and you do not leave it on bakelite switches for long periods, or get it on, or near any Bakelite cabinets.

Marc

Peter, I doubt it is that kitchen 'goo' that seems to cling onto and get inside everything in the immediate vicinity of the kitchen. That stuff has a pretty horrid smell, and is almost impossible to get off your fingers if you happen to touch it!

Chris

As I mentioned in my original post, it's not the fatty stearate film which comes from fried/grilled meat. The insides of the metal case are clean as a whistle.

It came off reasonably easily with Q-tips dipped in metho, so whatever it was is alcohol soluble.

Hmmm - you say only on the top surfaces, so that means it has probably precipitated from an aerosol mist of some sort.

What kind of mists get into radio shacks?

How about the residue of a DIY fumigation, or a vigorous deodorant spraying by a visiting spouse?

If the shack adjoined a bathroom, steam residue is also capable of forming a stick film, though it usually includes fibre from towels.

Life's great mysteries!

Maven

I thought of a roach bomb but these usually leave no residue.

More thoughts -

Maybe a 2-stage process.

1. Cabinet has been polished with a furniture polish or even a floor polish containing a wax.

2. A later aerosol of hydrocarbons, say a fumigant, some spray-painting, or something lacquered and left to dry nearby, has partly emulsified into the wax residue and left it soft and sticky.

I've seen effects like that after cleaning some older wax-sprayed printed circuit boards with a hydrocarbon.

As to cleaning - I see you were successful with metho, but with any old plastics I would carefully test turps and metho on the inside of the cabinet somewhere - I've ruined some plastics surfaces with the wrong solvents, especially acetone.

Wax can be a real problem - detergents don't work reliably. I've seen mention of a solution of 1part vinegar to 3parts warm water as a cleanup option for waxes, but I haven't tried it myself.

Maven

This transceiver was built in the 60's. It has a steel case with the original paint on it. It's in pretty good condition given its age. Just a few scratches here and there.

Yes, you have to be very careful with solvents and plastics.

In using the metho I avoided anything that wasn't steel.

I have encouted the same substance in various electronic jobs I have done.

I have found this on wiring insulation and pvc piping used to rout wiring.

From early jukeboxes to a technics 80s turntable. Only the above mentioned items have this substance.

It could be the hydrocarbons used in the manufacture of the pvc plastics or wiring etc and when they dry out leave the solvent and residue behind.

In motor vehicle emission testing ,they remove the interior ,tyres, and any plastics when testing for hyrdrocarbon emission as these all excede the allowed levels.

Some I have found I need to use carburettor cleaner to remove. And only some not all components need doing.
Mainly wiring looms .

Vic.

The wiring in my case is all under chassis and the underside of the chassis is very clean apart from the odd bit of resin spatter from various repairs.

I have a Rowe AMI CD100 Laserstar jukebox -- their first CD model, but still uses the carousel and pick mechanism similar to 45 vinyl discs. I should check it out to see if it has the symptoms you mention.