For these old "wave soldered" boards, I use a glass baking dish large enough to hold the board and place in it a "pad" of paper towels between 1/8" to 1/4" thick depending on the height of the protrusions on the bottom side of the board. The board is then placed on the paper towel pad and 99% electronics grade alcohol added to soak the pad. If the board won't lie level and flat, I use 1/4-20 machine nuts as spacers in the corners of the board, and add more paper towels to the pad if necessary to keep the pad in contact with the board.
It is important that the alcohol level not get above the bottom of the board, as there always seem to be some components that won't take kindly to immersion in any kind of fluid (potentiometers, variable trimmer capacitors, etc.). And if they could, their protective stickers have already been removed after the original manufacturing was completed (piezo buzzers are a good example). I put a cardboard "cover" over it to slow evaporation, and check it periodically. Add more alcohol if necessary. When the old flux has been sufficiently softened, I tilt the board and scrub it clean with a toothbrush, washing down the mess with a little poured alcohol. Regards, Peter > > Message: 4 > Date: Wed, 24 Mar 2021 07:48:07 -0500 > From: "Jeffrey Birt" <[email protected]> > To: <[email protected]> > Subject: Re: [M100] In over my head? Or a Challenge!! > Message-ID: <[email protected]> > Content-Type: text/plain; charset="utf-8" > > I was also reminded this morning, by another email, of the evils of the > flux used on the M100. It can turn conductive and cause everything from the > machine being stuck in reset, to power supply issues to fantom key presses. > It is also a pain to clean off.....<snip><snip> > Jeff Birt > > >
