[Elecraft] Type of solder for constructing a K1

[Ron D'Eau Claire]

A lot of people have gone around that tree, JB! What you have should be
fine. 

I have several pounds of 60/40 lead-based solder on hand, so I use it. I
wash my hands after using it and don't put the solder in my mouth. 

I have also used many types of "silver solder" - some as mandated by the
manufacturer for use in repairing RF circuits where very high currents flow.
The issue with "silver solder" is the higher temperatures involved. 

Some builders have found that the higher temperatures required for the "lead
free" solders make damaging the board a serious concern. It's not so much
when initially building, assuming a decent iron is used, but in the event
that components need to be removed - especially with the through-hole
plating Elecraft provides. It can get tricky getting all of the solder out
of the hole without overheating the board and damaging a pad or trace. 

Many builders have ended up with pretty expensive "desoldering guns" to make
this a 'hammer-simple' procedure. Whatever you do, don't pull hard on a
component when de-soldering a lead. You can pull the plating right out of
the hole. The procedure I use is to remove one lead at a time by gentle
pressure AFTER the solder in the hole has melted. If necessary, I break the
part to make the leads accessible for removal one at a time. Once the leads
are out, any solder sucker will do a good job emptying the hole. Sometimes
it helps a LOT to first re-fill the hole with solder, melt it, then suck it
out. 

Of course, that's not something you'll do much of while building (hopefully)
but it does come up if you make any mods, mistakes or other changes. 

Of course the over-riding requirement, which I'm sure you know, is that your
solder be ROSIN core, not acid.

Ron AC7AC



-----Original Message-----
I am shortly about to start construction of an Elecraft K1.

I note the warnings given in the assembly manual about using the wrong 
type of solder. Thing is, I am an old timer and it is quite a long time 
since I built anything like this. In the past I have used multicore 
solder with a 60% tin and 40% lead mixture.

I gather that these days, due to the effects of lead, it is/has now 
being phased out from solder. I just bought a brand now roll of 'lead 
free' solder. The stated composition of this solder is Ag 4%, Sn95.5% 
and Cu 0.5%. I have tried making a few joints and other than it seeming 
to have a slightly higher melting point than the older types, it seems fine.

Will this new solder composition be OK for constructing the K1.

Sorry if this is a dumb question but I have been out of the building 
business for quite a few years.

Regards,

JB.