Fred,
Gary and I both have been using acetone for a long time.
If the board is flooded, the results can be catastrophic since residue
flows under components and makes a mess.
But carefully applied with a swab or small brush to a small area and
mopped up with a paper towel it will do the job very well. The contact
time *must* be short, and that is why one must work in small areas.
Yes, alcohol can do a good job of cleaning flux too, but needs to have
the same precautions - it can make just as much of a mess or more
because alcohol attracts water vapor and causes it to condense on the
surface being worked. Dip an opaque object in alcohol and remove it
with a paper towel - note that the object will be wet with moisture.
Besides, the job for the particular problem stated was not flux removal,
but removal of some unknown compound from connector pins. Alcohol is
likely to be ineffective.
73,
Don W3FPR
On 9/7/2015 7:02 PM, Fred Townsend wrote:
Don:
Acetone should NEVER be used in electronic assembles. Acetone causes both
long and short term effects on various components including the PCB. It
effects epoxy, lacquers, paints, and plastics, particularly polystyrenes
where its effects are almost instantaneous. Pour some in a polystyrene cup
and watch it immediately cloud up.
>From Wikipedia:
Acetone is a good solvent for many plastics and some synthetic fibers. It is
used for thinning polyester resin, cleaning tools used with it, and
dissolving two-part epoxies and superglue before they harden. It is used as
one of the volatile components of some paints and varnishes.
Polyester resin, also called gel coat, in case you don't know, is the stuff
PC boards are made of. Leave acetone in the paint department where it
belongs. I suggest alcohol, any kind as long as it pure, be used for
de-fluxing PC boards.
73, Fred, AE6QL
-----Original Message-----
From: Elecraft [mailto:[email protected]] On Behalf Of Don
Wilhelm
Sent: Monday, September 7, 2015 2:43 PM
To: Nick Lelyak
Cc: [email protected]
Subject: Re: [Elecraft] KSYN3A mod problem
Nick,
Yes, but it fails when it cools again - something is not making good
contact, and it may be residue from the cleaner. I can't be certain of
that, but I would get that cleaner residue off and try again.
I would suggest that you remove the cleaner residue from the contacts with
acetone - apply it with a brush or cotton swab and immediately wipe the area
with a clean cloth of paper towel. Do only a few pins at a time, and do not
let the acetone dry on the contacts or board.
You may want to mate and unmate the front panel and RF board several times,
cleaning between each to hopefully clean some of the 'goop' out of the
female header.
If you do not have gold pins on the connector to the front panel, consider
asking Elecraft for the gold replacement pins.
73,
Don W3FPR
On 9/7/2015 5:27 PM, Nick Lelyak wrote:
Thanks Don, Guy
appreciate yours quick response.
I found out that problem disappears when front panel warms up to 37 C
and more.
Looks like problem somewhere in FP. To clean main connector I used
Electronic Contact Cleaner. It may works not so good as Deoxit which
is not widely available in Canada. In any case to move on have to buy
Deoxit first.
Thanks again
73, Nick VE3FJ
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