Cleaning Circuit Board

Discussion in 'General Electronics Chat' started by axeman22, Nov 23, 2009.

  1. axeman22

    Thread Starter Active Member

    Jun 8, 2009

    I have an Icom antenna tuner as per in the pics. It's from my 4WD and it sits up inside the bull bar, protected from elements but not from water splashing in etc. It's supposed to be waterproof but some moisture does over time get in, so I clean it periodically.

    I had oxidization on it this time and I tried to clean it using the Jaycar 'electronics cleaning solvent' as in the pic but it just turned into a sticky mess and then dried all white.

    Looking for advice on

    • What the white stuff is that dried?
    • How do you normally clean the lacquer coating off in a non destructive way..?
    • how to clean it off an make it look all nice an new? (same as above maybe)
    • How to protect it from moisture for the future - I have some circuit board lacquer.?

    Appreciate all ideas!

  2. SgtWookie


    Jul 17, 2007
    Don't disturb the inductors at all. If you move/distort them even very slightly, you can throw it way out of tune.

    Looks like you have some isopropyl alcohol; that's one of the more safe cleaners.

    It is flammable, and burns with a nearly invisible blue flame. Isopropyl alcohol will dry out your skin, so you should wear protective gloves. I use small metal handled brushes with stiff black nylon bristles to apply/scrub with; here in the States they're called "acid brushes" and are usually available at auto supply stores.
    Images of acid brushes: brush&um=1&ie=UTF-8&sa=N&tab=wi

    Hard to say what the white stuff is. Might be mold/mildew residue.
  3. Paulo540


    Nov 23, 2009
    I'd venture to say that the white crap is flux residue from the board that was partially cleaned but remained as the solvent evaporated. You can see a glob of flux in the one closeup of the bottom. The board doesn't appear to have any extra coating "lacquer" and I wouldn't recommend applying any.

    Iso is a pretty good cleaner, make sure you use high % and a clean toothbrush and as wookie says, wear some nitrile gloves. I use a heat gun on lowwwww (don't ignite the vapors lol) to evaporate the schmeg and it generally comes out pretty spiffy. Or leave it under a regular light bulb works too.

    Just be super sure that all the solvent is gone before plugging it back in and seal the case with some liquid gasket or something instead of fussing with the actual board.

    Hope some/all of this helps
  4. BillB3857

    Senior Member

    Feb 28, 2009
    My experience in seeing the "white stuff" is that it is a reaction of water with the protective coating applied to the board. I've had success in making it go away by use of a heat gun. The dry heat tends to remove the moisture contamination.
  5. mcgyvr

    AAC Fanatic!

    Oct 15, 2009
    You should be able to apply a conformal coating to the board/components to help protect against further damage. Or build it a better housing.