Cleaning PCB's.

[Roger13]

Hi all.

I have a thread open regarding my Pioneer RT-707, which is noisy on one channel...still.

When I collected the deck it had collected a lot of dust inside, as it is missing it's case, and I'm wondering how best to clean it. I have done my best with my trusty paintbrush and a can of compressed air but a coating remains. I'm thinking a good workout with my paintbrush and some meths and allowing it to dry naturally before powering up. However, I'm concerned that the meths may be a problem for components. My knowledge is somewhat limited in this area.

If anyone has an alternative approach to this problem I'd be glad to hear it. I don't suppose this is causing the noise problem, but it won't be helping!

Cheers,
Roger.

[SeanStevens]

Meths is not ideal because of its water content.

A light going over with a dry toothbrush will get the worst off.



Then you want a mild solvent to take the grime off. I've used WD40 in the past and never killed a board - saying that, many forum members will now decend and warn of possible problems WD40 can cause.

Parafin?

SEAN

[geofy]

isopropyl alcohol IPA is the usual PCB cleaner.

[evingar]

I'd agree - IPA is the way to go. IMHO Meths is nowhere as near as good.

As an aside, "canned air" seems to be massively expensive for some reason.
Can anyone suggest a small compressor that would to the job? I'm thinking more of the size used for small air brushes than the colossal great things used by garages. Any recommendations ?

[Lucien Nunes]

Before using IPA to clean a board, test one corner first to ensure there isn't an overall coating that will dissolve and turn goopy. You can find boards with either flux residue or a lacquer coating that transforms into a nightmarish sticky thing when doused in solvent. If the goop gets into switches and presets etc it could cause major hassle with bad contact. These parts can also be more vulnerable to solvent damage than sealed components but generally IPA is pretty safe.

Lucien

[mrmagnetophon]

once someone mentioned spraying alcohol on and spraying it off with an air compresser.
just passing that on for people to think about.
-Chris

[evingar]

Originally Posted by mrmagnetophon

once someone mentioned spraying alcohol on and spraying it off with an air compresser.
just passing that on for people to think about.
-Chris

I'd always try and remove the alcohol with a soft cloth , otherwise all you tend to do is create a film of "grunge" over everything when it evapoartes - This is especially the case when trying to remove flux after rework.

Not sure if by using air to blow over the card, you are removing the contaminated IPA from the board, or merely making it dry quicker - I guess it all depends on how vigorous the air flow is.

[wave solder]

From the problems I have come across over the years you don't want to put WD40 anywhere near a PCB as it can get inside connectors and cause mayhem as the residue it leaves behind is an insulator it also causes a right mess. Paraffin will also cause similar problems. As has already been said IPA is the right thing to use.

[Roger13]

Thanks for that folks. IPA it is then! In reply to post #4, I agree. £15 for a can of 'air' is extortionate. I'll be looking into hobby shops in search of a mini compressor. If I find anything good I'll let you know.

Cheers,
Roger.

[Pilot Mariner]

At work we use a product called "Safewash" from RS.
Its a bit expensive but it removes all sorts of grime and dirt etc from pcbs to make them look like new - brush/spray on then wash with water and dry thoroughly.

I usually pinch a bit and use it on old radios (cabinets and chassis) - it makes a chassis look virtually like new and removes dirt/grime/nicotine from components and those hard to get at places. I've never had a problem with it.

Mark

[Richard]

Hi

I have always washed PCBs with warm water and a bit of washing up liquid, soft brush or tooth brush to scrub crap off.
Ovoid getting wound components wet, then rinse several times and put somewhere hot to dry for a few days, never had any problems.
Have done boards from microwaves, big steam combis, several lap top mother boards that got coffee and wine spilt on them..

Richard

[dseymo1]

An old car tyre and wheel will serve as a good resevoir of compressed air for this sort of thing, and can be 'recharged' using a compressor, footpump, airline or WHY. A fridge compressor will actually do very nicely, as long as the pipes are arranged to keep the oil in. Don't use a compressor which has overheated though, as apparently the oil can degrade and become pretty corrosive.

[evingar]

Originally Posted by dseymo1

An old car tyre and wheel will serve as a good resevoir of compressed air for this sort of thing, and can be 'recharged' using a compressor, footpump, airline or WHY. A fridge compressor will actually do very nicely, as long as the pipes are arranged to keep the oil in. Don't use a compressor which has overheated though, as apparently the oil can degrade and become pretty corrosive.

Thanks, nice idea, but I was thinking more of something that tucked away neatly at the back of the work bench
Fridge compressor sounds a good idea, have to look into it

[toshiba tony]

we used to repair the samsung and lg projection sets and sometimes coolant leaked from one of the tubes, if it was caught in time we used to soak the pcb,s overnight in warm soapy water, we never had a comeback, if the pcb was caught early on it was fine but if the coolant had been there for any length of time the board rotted, unfortunately leaking coolant doesnt draw any attention from the customer.

[Baggrus]

Years back a set of disco decks which had been exposed to copious quantities of beer over long periods..

Boards were coated in sticky stuff (dried beer!!) ciggie ash.. fluff.. dust and all kinds of gunk ..

Soaked them in the bath overnight with a dash of washing up liquid.. then gave them a good scrub with soap and rinsed them with lots of clean water.. put in airing cupboard to "dry" for a few days.. then sprayed them with that one time available (not sure if it still is) silicone waterproofing spray.. smelled like scotchguard tent waterproofing spray.. solvent and a bit rubbery.. after masking the edge connectors and sockets .. worked a treat thereafter.. was immune to beer which had been causing both turntables to revolve backwards at 99rpm..

The joys of being a tech in the music business.. sticking to floors every night......

[porty2001]

I'm quite new to this forum. I normally work with modern laptops and have used the warm water and washing up liquid method quite succesfully to remove dried soft drink from boards (after removing any soldered in batteries of course).

[Jamie-Skinner]

I use a normal brush from a dustpan and brush

[David G4EBT]

Might be worth trying brake cleaner, which comes in aerosols and is used for cleaning the dismantled components of car brakes, such as discs, pads, springs etc. I use it extensively for cleaning radio chassis - far superior to WD40, which I'm not a great fan off and don't let anywhere near radio chassis. I spray the brake cleaner on then work quickly, using a toothbrush or cotton buds to pick up the dissolved grime, wax, oil etc. It evaporates in seconds and leaves no oily film.

The non-chlorinated acetone-free cleaner seems to be quite benign and doesn't seem to dissolve plastic, rubber etc, but obviously needs to be used with caution. Wurth brand is much favoured and 500ml cans can be found for less than £4.00 on t'internet. (I stock up at Rufforth Park Autojumble near York, 1st Saturday each month).

Oh, and it's good for car brakes too!

Halfords stock a product called 'Muc Off' meant for cleaning grime off motorbike brakes and discs, but I'ver not tried it. (Yes, 'Muc' - not 'Muck').


David

[McMurdo]

I suppose it all depends on what the contamination is! Beer or chipfat is best washed off with water & fairy liquid, IPA wont shift it. Industrial greasy contamination is best fetched off with a solvent, IPA is the safest, years ago we used to wash boards with 1.1.1-trichloroethane but it did attack certain plastics.

There's a recent thread all about washing stuff in water.