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Cleaning vintage circuit boards

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NobodyIsHere

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Dec 21, 2006
Messages
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Hi,

Does anyone know the definitive way to safely clean vintage circuit boards of old dust and cigarette smoke film? I would like to clean them with the minimum risk of damage to the legacy circuits possible.

I have read many articles on the web, usenet, and even here but the advice is conflicting with some advocating soap and water, others using compressed air, or other techniques. The dangers range from metal corrosion to ESD and a whole host of confusing subjects.

Maybe there is no simple answer but I would like to clean some boards up. In particular, I have an older machine which just plain smells bad due to its unique history however, I am very hesitant to use vacuum cleaners or blowing compressed air due to the potential for ESD unless absolutely necessary.

Apparently you can use soap and water to clean circuit boards and it might work or it might not depending on who you ask. However, I'd rather leave them dirty and smelly rather than risk ruining an almost irreplaceable vintage circuit board.

Thanks in advance.

Andrew Lynch
 
My experience in restoring antique vacuum tube radios was that
everytime I could make it to look like new, it would give me a
great feeling as I had revived a piece of history :love:. But everytime
I made it even worse by rubbing it too much, tightening it too
hard, or twisting it too far so that it broke, I would feel really
bad about it :ashamed:.

As you might know, some of these old radios have the name of the cities,
where the short-wave transmission were originated from (radio station), printed on
a glass panel in front of the radio box. When you turn on the radio,
the front panel lights up and there is a very beautiful glow from these
printed names that is fun to watch. There was this 50 year old Philips
with a slightly dirty panel, and it seemed like a good idea to simply
wash the dirt with a little bit of soap and water. I removed the
glass panel and immersed it in a bucket of soap/water, and after about
an hour (ouch...I know what you are thinking...) I removed it to wipe it
off with a towel. To my supreme amazement/sorrow/horror :confused7:, the printed
names of the cities, that was 90% of the beauty of that glass panel, were
erased/dissolved beyond recognition!!!!

That felt like @#%$#@&*&^_)&*^%$ specially after all the hours I had
spent fixing the wooden box, the rear door, the inside and out :curse:. The
shock of that incident was so devastating, I couldn't even wash my
hands for several days... :thumbs:; I could not even look at that defaced
front panel (oaah......what have I done! :sad2:) .

The lesson I learned from that event (and several similar ones after
that... you know... I am a slow learner :dunce: ) was :

If it works, don't mess with it!

ziloo :biggrin:
 
I've had good luck with a smidge of dish soap and warm water and a toothbrush.... helped alot with the stability of my IBM 5150
 
I am in the "min. crowd" myself. Everytime my mother would clean the stove or clothes washer, neither would work for at least 1 day. Our last washer even stunk for years because she had used too much cleaning fluid and shorted out some wires in the back. I would go with maybe a vacuuming with that brush thing on the end and maybe the "pencil eraser" treatment on some dip leads (if not working to begin with). Otherwise, I have had the same experience. I didn't have any transportation for 1 week because an oil fitting was leaking a tiny bit "Oh, I'll just tighten that up a bit to stop that" CRACK, split the bolt in half, so 1 week waiting on a Norton Commando oil fitting bolt from the UK. Same with a Heathkit radio I built. "I'll just make sure this coil is in good" Broke it in half. It still worked but I bet my calibrated micro-henrys were way off.
 
I guess stinky and dusty but working beats clean and beautiful but broken anyday.

While working on projects, I have done my share of "I wish I hadn't of done that" too.

Oh well. Thanks for all the replies!

Andrew Lynch
 
Druid,

Yes, I have read about people using the dishwasher to clean circuit boards. I am not sure I am ready for that yet. It seems like it would risk of leaving water and/or calcium deposits behind. I am also concerned about possible physical damage from the water blasts knocking components off.

Do you use the dishwasher method? Is it safe?

I discussed this subject with a friend locally and he said he uses burst of compressed air to blast off the dust and cobwebs first and then cleans the boards in soapy water. Then rinses them in distilled water and finally an alcohol bath to get the remaining water into solution and off of the circuit board. Let it dry for I presume a day or two and it looks like new.

I am not sure what I am going to do but most likely nothing unless I am sure it is safe. I'd rather live with the dust and smell than dead boards.

Thanks!

Andrew Lynch
 
For delicate boards I use a brush and compressed air.

For stuff that I'm willing to risk I'll use a damp paper towel, Q-tips and the like.

I don't think there's anything wrong with submerging a board in lightly soapy water if you get a good, clean rinse and let it dry sufficiently. However, many of the boards I have contain various tags and stickers that would get ruined by that type of treatment. . .
 
Yeah, I use the dishwasher for almost everything that needs to be cleaned up. Mainboards, cards, power supplies, cases, even cables.

I wouldn't use dishwasher detergent though, too many additives. A few drops of dishsoap (doesn't leave a residue).

For tags and stickers, the ones that come off cleanly I take off and then glue back on. The ones that won't I just put a good coat of petroleum jelly on and then wipe it off later.

You only have to leave them in there for about 5 minutes (a wash and a rinse cycle) and it works best if put them in on their edge, not flat. Then take them out and stand them up on each edge for a few hours each and that should be it. BTW, keyboards work best keys down so the water doesn't collect inside.

I have run, literally, dozens of boards through the dishwasher without any ill effects.

Takes a bit of a leap of faith, but, it does work and it even take most, if not all, of any corrosion off chips, pins, connectors, whatever.

If you have an old board or card that you don't really care about, run it through and I think you'll see it comes out clean and un-harmed.
 
I have a tool that looks like a large kids paintbrush that is great for brushing dust from cards and boards.

I also had to replace the fan inside my IBM XT's original PSU as it became noisy. Inside the PSU there was a very thick layer of dust. I used a petrol-powered leaf blower to blow the dust out of it (from a distance of course). It worked fantastically! It would take ages to clean that up with the brush. I've used this method several times now.
 
Hello all!

My 2 cents worth.. I like warm soapy water and a paintbrush - then rinse the board and put it in the sun. Seems to work OK! (Take out any uv sensitive eproms before dosing with sunshine!!!). I also use a commercially available (in Australia) pcb cleaner - can help with greasy deposits and such when used with a toothbrush or whatever.

Kendall.
 
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