[Elecraft] Solder....again.....again

Fri Aug 29 10:52:00 2003

Hi all

I have built quite a few K2's (13+) and other Elecraft products. I =
currently have Kester 44 rosin core, Kester 245 no-clean and multicore =
solder on my bench. I would recommend the Kester 44 or the Multicore to =
anyone building an K2. I see no difference in the performance of the =
Multicore or the Kester 44. I would suggest the 63/37 tin to lead ratio =
as it has the lowest melting point and no plastic state when cooling. If =
a joint moves while in this plastic state, then it is likely that you =
will get a bad joint. The 63/37 solves this problem. The use of silver =
in the solder (about 2%) will make the alloy harder and more difficult =
to remove should a repair be required and there is no real reason to use =
it. The silver solder is used with surface mount parts because the =
solder is already saturated with silver so it will not dissolve the =
silver connection coatings on the parts when soldering them.=20

The Kester 44 and Multicore use a activated rosin core that is fairly =
active. That means the rosin will clean the joint of oxides quickly =
making a good joint. However it leaves a brown residue that gets darker =
with age. It is not conductive and not corrosive so it can be left on =
the board, it just does not look too good. The Kester 245 no-clean flux =
is a synthetic rosin that is clear. It does not show on the board as =
much as the natural rosin and if you are going to clean the board it =
strips easier with alcohol. The problem with it is it is not as active =
as the activated rosin and there is less of it in the core so it is more =
important to have a good soldering technique so you get good joints. =
Elecraft does not recommend it because it is harder to get good joints =
with inexperienced builders. I prefer the 245 no-clean because it makes =
a better looking board but I have 30 years experience soldering and can =
work with it with no problems. A new builder should use the Multicore or =
Kester 44. I have always used the .031 size solder but recently switched =
to the .020 that I like better

Don Brown =20

  ----- Original Message -----=20
  From: Francis Belliveau=20
  To: [email protected]=20
  Sent: Thursday, August 28, 2003 9:41 PM
  Subject: Re: [Elecraft] Solder....again.....

  On: Thursday, August 28, 2003 7:54 AM
  "Kevin B. G. Luxford" <[email protected]>

  wrote:
  > ...
  > emailed Kester but got no reply.  I am concerned that it could be
  > no-clean solder that Elecraft specifically warns us not to use.  =
Anyone
  > know anything about this Hi-Tech solder?
  >
  Please keep in mind that Elecraft originally recommended no-clean =
solder and
  changed that recommendation only because the silver content made =
component
  removal more difficult.  I bought a new spool on their recommendation =
and
  have used nothing else.  I have had problems with only a small =
percentage of
  holes being difficult to clean of solder after component removal.

  What you really want to avoid is the water soluble flux solder.

  Fran, KA4FRH
  K2 s/n 314

  _______________________________________________
  Elecraft mailing list: [email protected]
  You must be subscribed to post to the list.
  To subscribe or unsubscribe see: =
http://mailman.qth.net/mailman/listinfo/elecraft
  Elecraft Web Page: http://www.elecraft.com
  Also see: http://www.elecraft.com/elecraft_list_guidelines.htm

--- StripMime Report -- processed MIME parts ---
multipart/alternative
  text/plain (text body -- kept)
  text/html
The reason this message is shown is because the post was in HTML
or had an attachment.  Attachments are not allowed.  To learn how
to post in Plain-Text go to: http://www.expita.com/nomime.html  ---