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Cleaning beverage out of inside tube amp

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Hi folks,

I have searched for spills and cleaning so I thought to post.

How would you clean *(how have you cleaned?) an amplifier with a beverage spilled in it?

Can I just put it outside and spray the inside down with Methyl Hydrate? or even plain old white vinegar and let dry?
- I've removed the tubes
- I'll remove the faceplate and copy down any information that might be washed away

I recently picked up a Dynaco (my first Dynaco!) SCA-35. (cheap, see below)
It looks like a beverage of some sort was spilled in it/over it so I've started cleaning it, you know, just splash some warm soap and water on it....kidding

There's no burn marks so I imagine the spill occurred during storage, I'm guessing tossing a beverage into a live amp would cause scorch marks but I'm not going to test that.

Multimeter doesn't show any power in the caps, though I'll remove them before full cleaning as I believe this amp has not been used in 20 years so I'll replace the caps with one of those replacement boards from Triode.

I'll post pics if it helps.
 
Rather than just hosing the thing down with a cleaner of some sort, it seems that it would be more practical to just go through the thing with a damp rag and dry it as you go (or a light cleaner of some sort, like windex). If one were to go for the "hose it down" route, you'd probably want to use DI water to avoid corrosion and then immediately get it into a place with a warm airflow to dry. The former seems like a much more reasonable solution, to my mind, if a little more labor intensive.
If some liquid had been spilled in it while it was running, things may have indeed arced over. One of the nastiest things I've ever seen in terms of damaged gear was a small tube printed circuit board that someone had spilled some sort of liquid on while it was running... needless to say things got a bit crunchy and blackened, and not in a good way!
 
Some parts, such as rubber and the like, may not like methanol (methyl hydrate).

Pure water wont hurt anything so long as it gets completely dry. This may be impossible to do if paper transformer insulation or paper capacitors get wet though. It probably wont be any worse than the beverage...

Paper capacitors are bunk at this point if not hermetically sealed anyhow.
 
Hi Michael,
I've done this sort of thing often with test equipment and amplifiers. The cleaning fluid of choice is plain water or isopropyl alcohol. (rubbing alcohol) I prefer 91% but 70% will do as well. Isopropyl is safe for rubber and almost all plastics.

I use a small paint brush or tooth brush to swab it around and may even use a spray bottle of water to rinse it away. Use common sense and keep it out of critical areas like transformers and coils. When things are clean, dry it with a hair blow dryer and then leave it sit for a day in a warm place just to be sure. (This last step is not really necessary if you're sure it's good and dry.)

Victor
 
My vote goes for denatured alcohol. Dries much quicker than isopropyl, and reacts with very few plastics and rubbers, as well. Used in great measure in the electrical industry.

Even if you have a component that is reactive with D.A., keeping the contact time to a minimum will limit the actual damage to the component. The fast dry time is your friend.

Most beer, soda, coffee, etc will be completely cleaned away. No residue.

Also adding a fan directly onto the work area will force very fast drying. Works a charm.
 
Thanks

Thanks everyone, if I can I'll post before and after pics.

I'm going with the denatured alcohol, old toothbrushes and a couple of affordable synthetic bristle small paint brushes. ( I reckon I'll test the brushes in alcohol first, in case they melt)

if there's any SCA-35 enthusiasts in the house feel free to email me your favourite mods list (google turned up a lot on this amp).

:D
 
Michael,
The reason I suggested isopropyl is because denatured alcohol contains additives to make it undrinkable that are not friendly to plastics. These can include methanol or methy-ethel-ketone or even xylene. Drying time when using heat and forced air is not a big issue. If you're concerned about a small amount of water in the alcohol (you shouldn't be), then use anhydrous isopropyl alcohol. This is often sold as "dry gas" that you use in your car in winter. If you doubt what I advise, then read my tag line.

Regards, Victor
 
Reckon I'll try that isopropyl then.

Chemical industries produce xylene from petroleum. It is one of the top 30 chemicals produced in the United States in terms of volume.

Xylene is used as a solvent and in the printing, rubber, and leather industries. Xylene apparently has an alternative lifestyle.


Yeah, isopropyl sounds good.
 
Has anyone ever tried using Zippo lighter fluid as a circuit board / chassis cleaner? It dries really fast, leaving no residue. It takes away excess rosin like nobody's business. My only concern is what else it might be trying to dissolve (caps, resistors, fiberglass epoxy circuit boards, etc.)

Oh, and the whole catching fire and burning thing, too. :) Just keep it away from sparks and open flame. :)
 
Ty_Bower said:
Has anyone ever tried using Zippo lighter fluid as a circuit board / chassis cleaner? It dries really fast, leaving no residue. It takes away excess rosin like nobody's business. My only concern is what else it might be trying to dissolve (caps, resistors, fiberglass epoxy circuit boards, etc.)

Oh, and the whole catching fire and burning thing, too. :) Just keep it away from sparks and open flame. :)

Isnt Zippo lighter fluid Benzene ?


I am pretty sure it is or was. That stuff is bad news and fairly hazardous. Skin contact is as bad as the fumes.

That said, providing you avoid the above, & of course sparks, It even removes formica contact cement and bubble gum.
I removed some dried cocacola from an old guitar amp with it, But it was not a seriuos spill.

Trout
 
Solid state stuff, I strip it down as much as I can, removing boards and the like, and then run the boards and as much of the rest of the chassis as I can through the dishwasher.

I was horrified the first time I saw one of my friends do this, but it really does a great clean job, stuff comes out looking like new.

Older tube radio equipment I tend to take outside, spray it down with the garden hose, soak and brush it with Simple Green, then thoroughly rinse it clean and let it dry in the sun. When it's absolutely dry I give the tube sockets, switch contacts, etc., a shot of DeOxit D5, relube the moving parts, and it's good to use or put on display until I decide to use it

Hitting an expensive piece of gear with a garden hose is tough the first time, but gets easy with practice. As long as you use a bit of common sense and circumspection about the cleaning process, and make sure the device is absolutely dry before it is powered up again, soap and water should never cause you a problem. I would think radio gear with the meters, IF transformers, slugs, etc., would be lot more easily damaged than an old tube amplifier, but I have never lost a radio to a good cleaning.

I never use anything but Simple Green, or soap and water, and some people I know won't even use Simple Green, but it has never caused me any corrosion issues. Some over the counter cleaners can be corrosive to some materials.
 
Trout said:
Isnt Zippo lighter fluid Benzene?

I am pretty sure it is or was. That stuff is bad news and fairly hazardous. Skin contact is as bad as the fumes.

Maybe once upon a time, but not the stuff I use today. I've got a jug of Ronsonol - it's mostly naptha. I think the benzene content is less than 30 parts per million. http://www.cooperbooth.com/datasheets/160606.pdf

Not that naptha is especially good for you either... but hey, isn't that always the way it goes? Now, if I could just find a place that still sold the "good" carburetor dip. The "green" stuff they sell today just doesn't get the job done.
 
w5jag said:
Solid state stuff, I strip it down as much as I can, removing boards and the like, and then run the boards and as much of the rest of the chassis as I can through the dishwasher.

I was horrified the first time I saw one of my friends do this, but it really does a great clean job, stuff comes out looking like new.


Interesting thread this!

Anyone who's seen an high-volume assembly line for PCAs (assembled boards) that uses a water-wash soldering process, will have come across something like this. Usually after component placement+soldering and before the test/inspection processes, there is a large industrial wash-off machine.
It usually has a conveyor through it, 1 or 2 "wash" stages with high powered hot water jets (often just plain water), a rinse and forced hot air drying stages.
A lot of volume manufacturers now use "no-clean" soldering processes, which doesn't need the soldering flux washing away.

You're right, it does sound a bit odd if you've not seen it done before.

Personally I wouldn't use a dishwasher (don't have one at home anyway apart from me), as it's likely to have remains of detergent which'll leave a residue behind. Conversely, you might cover your dishes on the next wash, with less than pleasant fluxes or other accumulated grot. I usually get a bowl of warm clean water, and a soft-bristled brush (a new 3/4" paint brush), then a rinse of fresh hot water and maybe a rabbit-drier to blow warm air to dry.

One other thing to mention, just need to be careful what components are fitted to the PCA. Most things don't mind a quick soaking, but others don't! ;)


Cheers,
Chris.
 
It works.

I won't fill this thread with Dynaco SCA-35 stuff but after an hour or so of toothbrush and alcohol, then letting the extra evaporate the darn thing works.
Old tubes and old caps, hum dials adjust the hum down to tolerable levels, though I'd like it lower, no sparks etc.

Even running an ipod as source it sounds pretty good, near field anyway. If this is Dynaco's worst sounding amplifier (internet here say) maybe it's time I got into Dynaco
 
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