# Logic Board Corrosion Remover

#### iMayne

Joined Oct 20, 2011
8
Hello

Im trying to find ways to spend less on cleaning chemicals. I use Methyl Ethyl Ketone (MEK) to clean liquid spills off logic boards; added I use it with an Ultra Sonic Cleaner machine. Is there a cheaper chemical to get rid of corrosion off PCBs?

Regards

#### mcgyvr

Joined Oct 15, 2009
5,394
It really depends on what the corrosion is..
However I've seen everything from 409 to baking soda/water to rubbing/iso alcohol to MEK. Using a nylon or other soft bristle brush is recommended too.

My opinion is that if the board will/could see spills or is installed in a location that extensive corrosion could happen it should have been conformal coated prior.

#### iMayne

Joined Oct 20, 2011
8
409 and Baking Sode LOL. I know 99% Alcohol will do but something with Ultra Sonic Cleaners is what I'm after. My cleaner has the heating feature so the fumes rises which I don't like.

#### SgtWookie

Joined Jul 17, 2007
22,221
A brief dip into muriatic acid (available at pool supply stores for ~$3-$5/gallon) will strip corrosion off of many things. I mean a BRIEF dip; perhaps 30 seconds. The stuff is nasty; don't breath it nor get it on your skin/clothes. I wear rubber gloves and an apron, and use a fan in an open garage to blow the fumes away.

Then flush thoroughly with lots and lots of fresh water to dilute/remove the muriatic acid.

After that, shaking off the water and rinsing in 99% isopropyl alcohol will hasten the drying process. Isopropyl alcohol is hygroscopic (absorbs moisture out of the air) so you have to keep it covered.

Sticking a board into an oven that's been pre-heated to "warm" will help get it to dry faster.

#### Gdrumm

Joined Aug 29, 2008
684
I recently repaired a Car Battey Charger, and part of the fix was removing the button diodes and cleaning them with a small wire brush (corrosion had a silverish, greyish look).

I also cleaned some wire connectors with the wire brush, they were rusty looking.

I also cleaned some traces on the board with a plastic bristle brush (also silverish, greyish).

What causes that type corrosion, and can it be prevented with a light coating of grease or petrollium jelly?

Thanks,
Gary

#### Pipes59

Joined Nov 7, 2011
4
The cheapest and works great is actually very hot water with a small amount of dish soap. Apply with old tooth brush and get at as much debries as possible. The stiffer the brush the better. Repeat with very hot water less the soap thus rinsing the PC board. I have even just let the hot tap water pour over it while brushing away any residue.
Follow immediately with shake and pat dry. Then hair blower to ensure water is completely evaporated. Most electronics can take this as long as there is not power or battery back-up devices on board. If still in doubt turn oven on lowest setting and place in it for an hour or so.
Always be sure it is completely dry before applying any power.
Most think this will cause rusting down the road. My experience has proved that this is not the case. The water is not on the metals long enough for that process to start. There are also protective sprays you can get to apply after a good cleaning to inhibit corrosion if enviroment is a problem.
Cheers,

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#### Evil Lurker

Joined Aug 25, 2011
116
Dow Scrubbing bubbles shower cleaner is the best stuff I have tried. Its a quaternary ammonium compound as the active ingredient so its gentle, pH neutral, and rinses clean. It even removes slight corrosion with a gentle scrubbing using a toothbrush.

There isn't too much difference in MEK's properties next to its chemical cousin, acetone. Its waaaaay to strong and IMO should NEVER be used on a PCB. MEK can eat certain kinds of plastic and is hell on capacitor bungs.

#### thatoneguy

Joined Feb 19, 2009
6,359
If this is something you are repeatedly having to do to the same boards, I'd suggest ordering a Conformal Spray after your cleaning and drying cycle. Chemtronics makes a few, clear and opaque, as well as other companies.

This would be the solution to your corrosion issues, but not the cleaning part.