PCB's- Dishwasher safe or not???

jmduncan

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OK, the jury is out on most posts for cleaning PCB's. I need to clean some up before repairs and I am interested in the dishwasher method, since it seems to be the easiest.

Who is in favor of the diswasher?

Who has had issues using the dishwasher?

Once again, thanks for your input!
 
I've had success lately with the dollar store variety of Simple Green and using a sprayer in the kitchen sink at work to rinse it all off. and then since I'm doing this at work, I have the luxury of those bathroom hand dryers to dry the excess of the water off with. :p

I'm actually kind of shocked with how many dudes on here are older and married that no one ever suggested using a hair dryer to dry it the same way as I do it with the hand dryer. most people say "I will let it dry for 2 weeks", but I haven't blown anything up doing it my way and letting it sit a whole day for about 2 days total before powering up again.

the trick is to make sure the hard to reach spots get dried, like under IC sockets or in potentiometers and anything else. I've washed several monitor chassis, if you happen to have to do those, make sure you get as little water in the neck socket or width coil and the like as possible.

if you aren't in any rush, you can just do the box fan method for a couple days, or a dehumidifier would be even better.

the washing part isn't the problem, it's drying it lol. I feel my way is significantly less abrasive (and a lot faster) than using a dishwasher.
 
I've never done it, and I'm against it because I think that subjecting a 30 year old PCB to unknown stresses of heat and water pressure in the dishwasher just doesn't make sense to me. I know lots of people do it, but I feel it's an unnecessary stress that may lead to later problems (No, I don't have any data to back that up. And no one has any data that says it WON'T cause later problems either).

If you really want the board cleaned off, do it manually in the sink so that you can spray everything with some care. There's no need for high pressure - use a soft dish cleaning brush to help move the dirt along. And of course, make sure the board dries well before you power back up.

For spot cleaning I personally use alcohol and an acid brush, but if you really need to clean the whole board, I suppose plain water is a valid way to approach it.

I'd also recommend using de-oxit or something on edge connectors after cleaning. It can't hurt, and that's about the only place that impurities from the water could give you any annoyance.
 
There are plenty of threads on this subject if you'd do a quick search.

I worked for a grey market Apple repair depot back in the mid 90s and we washed hundreds upon hundreds of boards to clean them up before repairs. We even washed the Apple II series and Mac keyboards back when they used to be repairable but came in full of puke from sick schoolkids.

We *never* had a single item come back for warranty work because of cleaning issues.

I use a toothbrush and liquid dishwashing soap then dry boards in the oven at 170F. Best results are from a gas oven but if all you have is electric then put a cookie sheet between the element and the board to avoid radiant heat issues.

RJ

PS: Don't wash batteries!
 
Leaving things to dry for a couple of weeks always seems like a good way to let rust take hold. I hang PCBs on the washing line on a hot day, this usually leaves them almost too hot to touch after an hour or so, and utterly bone dry!

Remove all socketed chips first tho, as you will lose all the stickers on the board, and on any chips.
 
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thank you for all the info. @channelmanic, I know there are a ton of threads on this subject. Like most things so far I have found there are many different opinions on how to do one thing.

I think I like the hair dryer and maybe even the de-humidifier to follow. I may try one set in the dishwasher though. For some reason ever since I read about people like omegaman popping PCB's in the dishwasher I have been kind of itching to do it. I jus wanted to hear from the guys who have and if they have really ever noticed any ill effects.
 
I have tried a dishwasher in the past on a mother board for a computer that had cat piss on it. That was one really clean board but all of the jumpers came off and there was not much info on them so that did not really work for me.

The Operation Wolf boards I will NEVER put in a dishwasher as the custom sip are getting harder to come by and they are so frail.

I have a few boards I have considered the idea but wife won't be home when I do this.
 
I washed one today. I do it in the sink with water and a toothbrush. I remove any socketed chips and go from there. Worst part is protecting serial number stickers, or any other labels on the board. I submerge the board in an inch or 2 of water (unless labels dictate I do it differently), scrub, then rinse with a sprayer. After that, I shake it dry, and lightly towel dry, then hit it with the hair dryer to aid in quick drying. My final 2 acts are 1) blow really hard into the empty sockets to get the trapped water out, and 2) finish off with a leaf blower. The leaf blower is high speed and gets any remaining drops that I couldn't get out previolsy. Then, if the leaf blower pushed too much water out, I might hit it with the hair dryer again.

From start to finish, it took me 2 hours (mostly cleaning and detailing some hard to reach areas with alcohol wipes, toothpicks, and qtips), and I had it back in my cab and running. 2 weeks seems extremely long to wait.

I've done this countless times and never had an issue.

I've never tried the dish washer - I don't mind doing it by hand. Now, if I had 300 PCBs, then I might look at the dishwasher!
 
I usually only do monitor chassis but have washed a little of everything at one time or another. I use hot soapy water and a paint brush. Then I dry with compressed shop air. If you really wanted to get fancy you could make a container to put the board in and pull a vacuum on it. Moisture evaporates very readily under vacuum.
Like others have said, never had a single issue with any boards I have washed. The most important thing it to make sure its completely dry before powering up.
 
Leaving things to dry for a couple of weeks always seems like a good way to let rust take hold. I hang PCBs on the washing line on a hot day, this usually leaves them almost too hot to touch after an hour or so, and utterly bone dry!

Remove all socketed chips first tho, as you will lose all the stickers on the board, and on any chips.




I would imagine the home user doesn`t need to get this technical , is this a fair comment ?

I use the vacuum cleaner with a nice soft bristle brush , anything that matters comes off easy [ dust related ] , spilt liquids , or even oils etc , well maybe , the tracks and component feet need some sort of detergent with warm water , but the dishwasher ?


I don`t know about longetivity after this , ie , the delamination of solder tracks to boards issue . I think a dishwasher is far too mechanical for such an important component .

This is a laymans comment , based on common sense and practicality , it might not be correct .
 
I use a toothbrush and liquid dishwashing soap then dry boards in the oven at 170F. Best results are from a gas oven but if all you have is electric then put a cookie sheet between the element and the board to avoid radiant heat issues.

I preheat the oven to 170F and then turn it off before putting the boards in, just so I don't have to worry about cooking the boards when the element turns on. It stays pretty hot in there as long as you don't open the door.

For cleaning, I usually use simple green and a paint brush in the kitchen sink, then rinse with the sprayer. I hit it with the hair dryer to get most of the water off, then put it in the oven to dry completely. I'm going to give the dishwasher a try next time though.
 
I've washed plenty of PCB's and monitor chassis in the dishwasher. If something is really filthy I'll rinse it off first (to minimize the amount of crud in the dishwasher), and toss it in. I dry the boards in the oven. Sure, a hair dryer works - I use it for some things, but it takes too darn long, and it's tedious. Heck, it takes too long to dry my hair with the stupid thing. Much easier to put the board in the oven to dry :)

The only issue I've had is on some really old boards (Space Invaders) where the green solder mask discolored. I don't know if was due to the heat, or the detergent, but it did not affect the board itself, it just looked funny.

I've never really cared about things like the serial number stickers or EPROM labels. Partly because usually if a board is filthy enough to wash, it's filthy enough to have nasty/missing stickers. If the labels fall off the EPROMs, I'll stick something over them later. Also... who really cares about the serial number sticker on a PCB? Really?

-Ian
 
I have always just washed boards in the sink with dish soap and a soft brush - this goes back to the 80' when I started work in TV/VCR repair. I time is a factor I use a compressor to blow the boards dry, but if not in a rush I will either use the compressor to get the bulk of the water off and then let sit for a few days or just leave in the sink to dry.

Don't see a problem with the dish washer method, I just don't really see what is to be gained.
 
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Don't see a problem with the dish washer method, I just don't really see what is to be gained.

Because tossing the board in the dishwasher is a whole lot easier than scrubbing it in the sink. Also, it does a better job of getting the crud out of tight places, like between components on monitor chassis.

-Ian
 
I would imagine the home user doesn`t need to get this technical , is this a fair comment ?

I use the vacuum cleaner with a nice soft bristle brush , anything that matters comes off easy [ dust related ] , spilt liquids , or even oils etc , well maybe , the tracks and component feet need some sort of detergent with warm water , but the dishwasher ?


I don`t know about longetivity after this , ie , the delamination of solder tracks to boards issue . I think a dishwasher is far too mechanical for such an important component .

This is a laymans comment , based on common sense and practicality , it might not be correct .

I never liked the vaccum brushes as they generate a lot of static.

As for delamination, I've never witnessed anything of the sort in all my years of board cleaning. It takes heat to cause traces to come up. You are FAR more likely to do that by putting too much heat on the pad/trace with your soldering iron than by cleaning the board.

As for the Op mentioning Space Invader boards with discoloration on the trace coatings, that is most likely the coating coming loose from the trace by getting water between them. As long as it's dried fully that will not cause any long term issues.
 
Being able to wash it depends on what is on the board. There are certain items on boards that are never intended to get wet such as relays. If the board is all IC's/sockets, resistors, caps, etc - then go ahead and wash away. My employer used to keep a Sears Kenmore dishwasher running for small board washing batches. Large batches of boards used to go through a machine that looked more like a miniature car wash.

I have seen lots of DIP switches affected by washing. They tend to get a little bit of water inside and no amount of blowing or heating ever quite gets them dried out. When first installed, the DIP switch works fine. But, after a few years, the DIP switch contacts turn a nice shade of blue-green. As long as you never changed the DIP switch settings then you were fine. And if you changed a DIP switch setting from closed to open, you were also fine. Problems came about when you went from open to closed... and the corrosion acts as an inline resistor.

Ed
 
If you do try the dishwasher, make sure you use a setting that does not include the heated dry setting.

I have never tried the dishwasher, though I have used a garden hose and a kitchen cleaner (Formula 409, IIRC) on a few monitor chassis. This was followed by a couple of hours sitting in my garage in the summer (Texas garages in summer approximate a warm oven very closely :D).

I don't use these methods on Williams boards because of the paper stickers. Although I have gotten a few boards where I am pretty sure they went through the dishwasher with dishwasher soap. The boards are bleached pretty severely. :eek:

ken
 
just as I figured a boat load of information. I am going to use a set of boards that needs heavy repairs to try out the dishwasher.

@ YellowDog, good call on the heat dry settings for the dishwasher. I know I would not have thought twice about changing the settings and come back with a horror story.
 
I've never really cared about things like the serial number stickers or EPROM labels. Partly because usually if a board is filthy enough to wash, it's filthy enough to have nasty/missing stickers. If the labels fall off the EPROMs, I'll stick something over them later. Also... who really cares about the serial number sticker on a PCB? Really?

-Ian

Yes really. If you're selling a cab as original, it helps (in my opinion) to have the serial number on the cab match the serial number(s) on the PCB(s). It shows that the all original cab you are selling really is all original and well cared for. People reproduce stickers in exacting detail for the back of cabs, and many would like to reproduce stickers for PCBs as well. It has to do with that "restoration" thing. If you're selling an original Atari Tempest with serial number #002, it would be better if your PCBs didn't have serial numbers 27658, 15456, and 03406.

Just my 2 cents.
 
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