Next time, just before you hit the Post button,
you might want to look at the title of the thread.
If he just meant *solder*,
he wouldn't have included *low-temp* in the Subject line.

so -
what's your "favorite" solder, dude?

On Sat, 15 Jan 2005 23:43:35 -0500 "Hal Rosser"
wrote:

eutectic (if my memory serves) just means it's either solid or liquid - and
won't just 'soften' - like ice and water.

The eutectic alloy is the one which has the right proportions to give
it the minimum melting point for a given set of constituent metals.
I've only seen the word applied to binary alloys, but I suppose it
could be applied to alloys of 3 or more metals, too. I'm not sure if
that's a proper use of the term, however.

A side effect of using the eutectic alloy is that there is a
distinctive melting point. When the alloy is non-eutectic, there are
separate solidus and liquidus points, between which the alloy is just
more or less "slushy."

There is no slushy region when a eutectic alloy melts. This sounds
like what Hal was describing above.

-
-----------------------------------------------
Jim Adney
Madison, WI 53711 USA
-----------------------------------------------

The eutectic combination of tin and lead is 63% tin, 37% lead. 60/40 has
a slightly higher melting point, and unlike the eutectic alloy, has a
plastic stage between liquid and solid. Consequently, 63/37 is a better
choice for solder.

Roy Lewallen, W7EL

Hal Rosser wrote:

plain old 60-40 rosin-core electrical solder has worked well for me - got
mine at a hamfest on a half-pound roll.
the silver stuff (I believe) melts at higher temperatures - and higher
temperatures are not good for electronics.
eutectic (if my memory serves) just means it's either solid or liquid - and
won't just 'soften' - like ice and water.
hth
Hal w4pmj

In article ,
Roy Lewallen wrote:

The eutectic combination of tin and lead is 63% tin, 37% lead. 60/40 has
a slightly higher melting point, and unlike the eutectic alloy, has a
plastic stage between liquid and solid. Consequently, 63/37 is a better
choice for solder.

I understand that there's a tradeoff involved. The 63/37 eutectic has
a lower melting point and no plastic stage, and some people feel that
the latter reduces the risk of 'cold' solder joints somewhat. On the
other hand, I've read that the 60/40 alloy is somewhat superior in its
"wetting" property - it adheres and bonds to some base metals better
than the eutectic does, and might make superior joints as a result.

I tend to prefer the eutectic, or a eutectic modified with 2% silver.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

2 or 3% silver is added to tin-lead solder to prevent leaching of gold
or silver terminations from certain surface mount components (and the
terminal strips in very old Tektronix scopes). These components are
often used for hybrid circuits, but solder-coated terminations seem a
lot more common for components intended for PCB use. I haven't seen a
leaching problem with the solder-coated terminations using ordinary
tin-lead solder.

Is there some other advantage of a 2 or 3% silver addition?

Roy Lewallen, W7EL

Dave Platt wrote:
. . .

I tend to prefer the eutectic, or a eutectic modified with 2% silver.

Yes. This little addition of silver adds a very LARGE amount of strength to
the joint. PLEASE don't ask me to climb up to the top shelf to give you
numbers.... {;-)

Jim


Is there some other advantage of a 2 or 3% silver addition?

Roy Lewallen, W7EL

In rec.radio.amateur.antenna Roy Lewallen wrote:
2 or 3% silver is added to tin-lead solder to prevent leaching of gold
or silver terminations from certain surface mount components (and the
terminal strips in very old Tektronix scopes). These components are
often used for hybrid circuits, but solder-coated terminations seem a
lot more common for components intended for PCB use. I haven't seen a
leaching problem with the solder-coated terminations using ordinary
tin-lead solder.

Is there some other advantage of a 2 or 3% silver addition?

Roy Lewallen, W7EL

Higher melting point and greater strength; specialty applications.

--
Jim Pennino

Remove -spam-sux to reply.

In article ,
Roy Lewallen wrote:

2 or 3% silver is added to tin-lead solder to prevent leaching of gold
or silver terminations from certain surface mount components (and the
terminal strips in very old Tektronix scopes). These components are
often used for hybrid circuits, but solder-coated terminations seem a
lot more common for components intended for PCB use. I haven't seen a
leaching problem with the solder-coated terminations using ordinary
tin-lead solder.

Is there some other advantage of a 2 or 3% silver addition?

A fair number of surface-mount components (caps and resistors) use
silvered terminations. Some of them have an anti-leaching coating
over the silver (nickel, or solder with or without silver), others
don't. There's also silver plating on some of the RF connectors I
use. I'm probably being excessively cautious, but figure that it
can't hurt to use a silver-loaded solder and it might save me one or
two failures over time.

--
Dave Platt AE6EO
Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior
I do _not_ wish to receive unsolicited commercial email, and I will
boycott any company which has the gall to send me such ads!

"Roy Lewallen" wrote in message ...

snip
(and the
terminal strips in very old Tektronix scopes).
snip
Roy Lewallen, W7EL

HEY! I resemble that statement. What do you mean VERY OLD? Seems like just last week.

--
Crazy George
Remove N O and S P A M imbedded in return address

On Sat, 15 Jan 2005 23:43:35 -0500, Hal Rosser wrote:

wrote in message
oups.com...
I've had good luck with the kester 62/36/2% silver stuff, which is
eutectic.

Many many years ago, I had some luck with a indium-bismuth solder paste
in syringes from Indium Corp. Haven't fiddled with any of their stuff
since then.

Radio Shack sells a bag of little peices of tape-form stuff. Never got
it to work well.

Favorites?

plain old 60-40 rosin-core electrical solder has worked well for me - got
mine at a hamfest on a half-pound roll.
the silver stuff (I believe) melts at higher temperatures - and higher
temperatures are not good for electronics.
eutectic (if my memory serves) just means it's either solid or liquid - and
won't just 'soften' - like ice and water.
hth
Hal w4pmj


63/37 solder is eutectic.