Date:         Sat, 8 Aug 2009 16:51:22 -0400
Reply-To:     David Beierl <dbeierl@ATTGLOBAL.NET>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         David Beierl <dbeierl@ATTGLOBAL.NET>
Subject:      Addendum Re: 2.1l ECU - Solder Fatigue
Comments: To: Bob Stevens <mtbiker62@gmail.com>
In-Reply-To:  <7.1.0.9.0.20090807013837.0640fd50@attglobal.net>
Content-Type: text/plain; charset="us-ascii"; format=flowed

At 01:54 AM 8/7/2009, David Beierl wrote:
>You always have to add at least a touch of 60/40 or 63/37 rosin-core
>solder to the tip to get good thermal contact with the
>rest.  Easiest way is to place (~20 ga or finer)

I didn't put enough emphasis on flux here.  The bad contact will
always have oxidized to some extent and require fluxing.  The tiny
amount in the bit of solder can be enough, but it's often useful to
dip the end of the solder in some additional rosin-type flux (*never*
plumber's flux), either liquid (hard to come by in less than gallons)
or paste (Radio Shack sells small tubs of rosin-in-grease, works great).

Also, these contacts are fairly small, and close enough together that
you must take care against solder bridges, and remove them if they
happen.  Radio Shack sells both desoldering braid and "solder
suckers."  Remember with the braid not to scrub against the foil pads.

You cannot do this work with a gun.  A 25-watt iron with a fairly
fine tip should work pretty well.  Staples sells remarkably
inexpensive little ring-type clip-on gooseneck magnifying fluorescent
lamps that can be a great help in getting everything to the right
place.  They also have larger  draughtsman's-type ones that take a
regular Type A light bulb.  Both types will give slightly more light
if you cover the lamp chamber with aluminum body tape.

  --
David Beierl - Providence RI USA -- http://pws.prserv.net/synergy/Vanagon/
'89 Po' White Star "Scamp"