Stan, Do NOT attempt to remove the flux - it is not conductive and will cause no problems, even though it may look slightly "messy". In fact, attempts at removing flux can result in unanticipated problems. If the flux residue plus solvent gets under connector headers or relays, or even ICs, it will not be completely removed and the residue left in those places can later make conductive paths where they should not be. I did work on one K1 that had been completely ruined by an attempt at removing the flux.
If you must clean a board, do it in small areas - do NOT flood the board with the solvent (yes, use de-natured alcohol, acetone can etch plastic components) - apply the solvent sparingly in a small area at a time, and blot it off with a paper towel. Alcohol attracts water from the air rapidly, and the reduced temperature of the board caused by rapid evaporation will cause the water to condense on the board - wipe it up too, but do not apply power until it has completely dried. If you feel you must remove the flux, build up a small board (like the RF Probe from the parts provided in the K2 kit), and practice your flux removal technique on that first so you know what to expect. If you want to avoid a large flux residue, use a solder with a mildly reactive flux, such as Kester 285. While Kester 44 is much better know, it has a highly reactive flux and leaves much more residue than the mildly reactive flux. Save the highly reactive flux for soldering jobs that have noticeable oxidation on the surfaces. 73, Don W3FPR On 9/8/2010 1:43 PM, stan levandowski wrote: > I've been told that it is good practice to clean a completed PC board > with either acetone or denatured alcohol and a small toothbrush. > > I could not bring myself to do this when I completed my KX1 - it just > seemed (at least to me) somewhat risky to be brushing a liquid with a > nylon toothbrush all over a populated board. > > Now I'm faced with the same issue as I begin my K2. I want to do > "everything right" because this K2 is going to be my "baby" -- but..... > > So I am asking for some opinions on just what the risk/benefits are and > perhaps to get some idea as to whether this is really a practical and > useful process or a "purist" finishing touch that returns marginal bang > for the buck. > > > This list hosted by: http://www.qsl.net > Please help support this email list: http://www.qsl.net/donate.html > ______________________________________________________________ Elecraft mailing list Home: http://mailman.qth.net/mailman/listinfo/elecraft Help: http://mailman.qth.net/mmfaq.htm Post: mailto:[email protected] This list hosted by: http://www.qsl.net Please help support this email list: http://www.qsl.net/donate.html
