Hi,
I'm doing some preliminary research and was unable to find information
on solder fluxes.
I need help.
Specifically with solder fluxes and activators used in cored solder
wire including rosin activated fluxes & no clean fluxes.
I've already spent several hours on Google, but didn't find this info.
Can you help me directly with as much details as required and /or
suggest some other site/group where I can get useful info on these
topics?
Look forward to hearing from the group,
Thanks and regards,
Bob
Most manufacturers of flux cored solders will keep their flux formulas
secret and I haven't yet seen anyone provide details of what is
contained in them. One only has to look at the flux data sheets from
Kester and you will see what I mean.
http://www.kester.com/en-us/datasheets/ds_dirdetail.aspx?location=Fluxes
I consider one of the best soldering alloys for electrical and
electronic applications is MAGNA 87EC which contains an activated flux
core which works extremely well. I have used this solder for
electronics work from around 1987 and I can attest to its
effectiveness. It is not cheap though, nor does it come in smaller
than 1.1mm gauge from memory. The last 1lb roll I bought back in 1993
cost me AUD90.00 then (USD66.00 currently). MAGNA ALLOYS
http://www.magnagroup.com/ gives this blurb on 87EC flux;
Flux cores
Many of today's solders are manufactured with an inner core of flux.
The reason is, of course, to supply the solder surrounding it with the
correct amount of anchor material at the correct time during
soldering. The flux must act as the anchor to the metal for the solder
alloy. It must clean the metal surface, penetrate it, de-corrode it
and have a perfect affinity with the solder, and work piece,
simultaneously. Only then can the bond take equal root between the two
sections being joined.
An example of this fact is Magna 87EC. The flux core is not a simple
water white resin as is common to the ordinary solder family; the
special Magna 87EC Flux consists of Sylvic acid which is a
heteroannulas diene.
At a given, preplanned temperature, the sylvic acid rearranges itself
into a neoabietic acid. It also contains a by-product of pimatic acid
which is a homannular diene. It is easily isomerized to abutic acid.
Also, a different form of acid (also pimatic) is also used in the
Magna 87EC Flux Core. This is a non conjugal diene which is stable to
acid.
Several activators are added to promote energy when heated. The
residue of the Magna 87EC Flux Core is a hard, transparent film of
excellent electrical insulation. It will not absorb water. Then, as
slightly more heat is applied, it undergoes disproportionation to a
pyroabietic acid mixture, both of which are chemically inert. Thus, it
begins its function as a strong acid that has powerful cleaning
capacity...and ends as a virtually non-corrosive residue.
It is a fact that a properly made Magna solder joint between two
pieces of steel has the full tensile strength of the steel itself. The
only problem is fear itself - maintenance engineers do not trust
soldered joints - because their only experience has been with ordinary
production type solders which often do fail. Once they realize that
there is a vast difference between Magna Maintenance Solder Alloys and
ordinary solders, they will have the confidence to perform repairs at
low heat they would never have attempted before.
