Put it to dry ON THE SUN (yes) for two or three days - of course, don't let it out on night - and you'll have mostly new boards.

On Fri, Nov 20, 2009 at 3:28 PM, Brian Lanning <brianlanning at gmail.com>wrote: Only if paper made. Usually they are plastic with a silicone glue

?Compressed air is the thing for drying boards after they're washed. ?Not canned air - you'll go broke buying those cans - but a real air compressor and a "blow gun" nozzle.

You're saying that's a static electricity hazard? ?How is that?

Compressed air is the thing for drying boards after they're washed. Not canned air - you'll go broke buying those cans - but a real air compressor and a "blow gun" nozzle. Just blow all the water down to one corner of the board and then off the edge. It even gets the water out from underneath components and from inside connector and socket pins. I routinely wash new boards after I've assembled them to remove solder flux, and you can completely dry a board in a couple of minutes this way.

Disassemble to the smallest parts you can get, wash everything with water and neutral soap, rinse many times with water. Put it to dry ON THE SUN (yes) for two or three days - of course, don't let it out on night - and

Why does Agnes get to have all the fun?! :-)

at least use distilled water?

Dan Gahlinger wrote: I use distilled water for a rinse after cleaning, then Isopropyl alcohol to remove the water. Barry

I was looking at the isopropyl container that I have and noticed that it is a 50/50 mix of alcohol and water. I wonder if you can get a 100% (or as near as possible) w/o going to a chemical supply house.

-----Original Message----- From: cisin at xenosoft.com Sent: Sat, 21 Nov 2009 16:36:02 -0800 (PST) To: cctalk at classiccmp.org Subject: Re: Water damage On Fri, 20 Nov 2009, jim s wrote: Always check the label carefully. In USA, you can get 90% isopropyl alcohol in dupermarkets and drug stores, although the weak stuff is much more common.

What about the 99% stuff?

-----Original Message----- From: ajp166 at verizon.net Sent: Sat, 21 Nov 2009 23:01:34 -0500 To: Subject: Re: Water damage 90% iso is fine. I used to service marine gear. During that time I's get one that had been dunked in the nastiest, saltwater. The procedure was know to those that did that kind of service. -First immerse in clean fresh water. -Open unit to fully expose -Then drain and repeat with fresh (not reused) water to get the salt out. -After several rinses a bath in any Isopropanol to kill any bugs that might have been in the water. That also means runoff or other sources of water. It's critically important to get out salts as many are hydroscopic even after drying. Generally for the last 30 years water and sometimes surfactants are the common material for cleaning freshly assembled boards. It's also safer and easiest to dispose of in a safe way. Bake in an oven at 180F (warm but not hot) to drive out all water. Replace any paper parts (speaker) or other items that may have been affected by water and lubricate as needed (shafts, switches, pots). If the unit hadn't been in the salt for more than a day full recovery was common. Longer than that and you get electrolysis and parts literally start falling off the boards. Water is ok to a point. It should never be allowed to sit as corrosion is the real problem. With boards and electronics that generally means electrolytic corrosion as you have dissimilar metals and often the water is not clean. Clean water is a poor conductor and less a problem so cleaning with water is least damaging is it's is distilled. Also distilled will not remain nonionic if the board is dirty, clean it first. I've cleaned cruddy PDP-8 and PDP11 boards in the dishwasher. I had a S100 crate that was so filthy I would never bring it in the house until it got hosed off and initially scrubbed outdoors then disassembled for a pass through a dish washer. Bake them dry and they look factory new and have never given problems. I recently got a ham transceiver that was owned by a smoker and stored in a dusty dirty garage and ran that through the dish washer (after removing the tubes, meters and fully opening it up) after drying and lubricating the tuning mechanism it looks nearly new save for scratches. When assembled and few known problems repaired before washing it worked as it should. This was a tube (valve) radio employing voltages like 150, 300 and 750 so any conductive path (including dirt) is going to be a real issue. Cleaning also cleared a few HV arcs that were caused by the greasy dust when first tested. NOTE: water is the least caustic and also the least damaging cleaning material. Many solvents will damage plastics including older IC encapsulents, plastic cased transistors as well as adhesives to name a few. Also water (and maybe some mild soap) will remove soot, dirt, dust, and possible fungal residues (molds). Some parts like power transformers are a pain to wash but if water has gotten to them then a rinse and thorough bake is always required. Water is not the problem but how to deal with all the other things that come with it or result from it laying in a puddle of dirty water. Allison Ben wrote: > N0body H0me wrote: >> If you live someplace where there's agricultural stuff going on, you >> can probably get it from a place >> that sells farming supplies (I get mine from a >> local tractor dealership, for example). Call 'em >> up on the phone and ask. . . >> >> Do *NOT* use the stuff you get from the drug stores-- even the 90% >> stuff, it still has too >> much water for electronics use. The 100% iso >> evaporates *completely* at room temprature. >> The water content in the other stuff tends to linger. Not good. > What about the 99% stuff? >

I don't recall any barrel battery on my A600. I have two A600's though, one with the metal shield (on last attempt I gave up opening it up on fear of wrecking the case) and one without (which had the case clips damaged by the previous user... no metal shielding and no barrel battery that I can recall). I guess it depends on which revision A600 board you have. The one I opened up is stamped "A300 June Bug".

The rest of the components are surface mounted and look to be okay (apart from the RF TV circuits which are almost impossible to dry out even with a hair dryer)

accelerators/third party add-on boards, so luckily this stuff doesn't have a barrel type battery. There are button type batteries on the add-on boards that definitely have leaked and I've already removed them. I do wonder if they leaked beforehand or not since they were actually quite dry.

What do you mean by "leaked caps"? I've not seen water cause caps to do anything. Are you sure that is not some glue put on the capacitors by the manufacturer to secure them to the PCB? This is not uncommon...

What about doing what some board manufacturers do - run the boards through the dishwasher. I do not know what soap (if any) they use, but it has been discussed many times on the 'net and you should be able to find ample valid references to help you decide if you want to try it.

Date: Sat, 21 Nov 2009 09:48:28 -0600 Subject: Re: Water damage From: brianlanning at gmail.com To: cctalk at classiccmp.org On Sat, Nov 21, 2009 at 8:31 AM, Dave Taylor wrote: water + electronics + electricity = bad. This is because it causes short circuits that can fry components. As long as its completely dry, there's no water to cause the shorts. The other problem is corrosion. Pure water wouldn't do that, but all the other crud floating around in water is left on the component when water dries, encouraging corrosion. This is why you wash it off with a solvent (that doesn't leave deposits of its own). brian

On 21/11/2009 16:54, dwight elvey wrote: That surprises me. Pure water, H2O, does partly dissociate, but in doing so it forms an exactly equal number of OH- hydroxyl ions and H + hydrogen ions -- the latter being what makes an acid acidic, and the former being what makes an alkali alkaline. Pure water, in fact, is virtually the definition of pH 7.0, which is absolutely neutral. I suspect what's actually happened is that dissolved gasses made the water acidic, but then it's not truly pure. For example, dissolving CO2 in water makes carbonic acid.

Water is often termed the ultimate solvent. H2O (the molecule) has some interesting electrostatic properties

On Sat, Nov 21, 2009 at 8:31 AM, Dave Taylor <ript at disasterarea.net> wrote: water + electronics + electricity = bad. This is because it causes short circuits that can fry components. As long as its completely dry, there's no water to cause the shorts. The other problem is corrosion. Pure water wouldn't do that, but all the other crud floating around in water is left on the component when water dries, encouraging corrosion. This is why you wash it off with a solvent (that doesn't leave deposits of its own). brian

http://www.fanboy.com/2009/11/dec-pc-challenge-1982.html This is an promotional film produced by Digital Equipment Corporation (DEC) documents their attempt to enter the PC market in 1982. DEC owned a major chunk of the mini-computer market and to their credit they got the idea that the PC was the wave of the future and they knew they had to compete.

What about doing what some board manufacturers do - run the boards through the dishwasher. I do not know what soap (if any) they use, but it has been discussed many times on the 'net and you should be able to find ample valid references to help you decide if you want to try it.