ISTR from many years in my past that Copper Sulphate and Salt can be used an etchant to remove tin and other plating from copper. Does someone know the relevant quantities to use to make up about 100ml of etchant? Relevance to this list is that I have some gold flashed electrolytic copper spades, and a suitable four core plus guard cable, but want to strip the tinning off the wire to make low thermal EMF leads. I have crimp tools and also have a small amount of Sn/Cd solder I found in an old Marconi RF meter. Which would be the better to use to make the connection? PS Why do the interesting discussions about Solartron 7081 meters happen while I'm on holiday and have suspended my subscription? PPS How were those leakage currents in the errant 7081 measured? If you reply to the list about this please start a new thread. Thanks Dave

Asked and some answers on Google: http://www.finishing.com/319/63.shtml -John ============= > ISTR from many years in my past that Copper Sulphate and Salt can be used > an etchant to remove tin and other plating from copper. Does someone > know the relevant quantities to use to make up about 100ml of etchant? > > Relevance to this list is that I have some gold flashed electrolytic > copper spades, and a suitable four core plus guard cable, but want to > strip the tinning off the wire to make low thermal EMF leads. > > I have crimp tools and also have a small amount of Sn/Cd solder I found in > an old Marconi RF meter. Which would be the better to use to make the > connection? > > PS Why do the interesting discussions about Solartron 7081 meters happen > while I'm on holiday and have suspended my subscription? > > PPS How were those leakage currents in the errant 7081 measured? If you > reply to the list about this please start a new thread. > > Thanks > Dave > > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > >

John wrote: >Asked and some answers on Google: One other potential worry -- whatever you use, it will wick between the wire strands and under the insulation, and it's pretty much dead certain that you will never get it all rinsed out. Not so much of a problem with spade lugs, but potentially a real problem with stranded wire. Much better to get some unplated copper wire and use the plated wire for another project. Also, is the OP absolutely certain that the plating is tin? Nickel is more usual. If it is tin, is there lead, as well (solder-plated)? Best regards, Charles

I wrote: >Also, is the OP absolutely certain that the plating is tin? Nickel >is more usual. If it is tin, is there lead, as well (solder-plated)? Was thinking of lugs, not wire when I wrote "Nickel is more usual." Not true for wire. Best regards, Charles

Silver is common for Teflon wire. You can get OHFC wire pretty wasily these days. The audiophools trip out on it. Best, -John ================ > I wrote: > >>Also, is the OP absolutely certain that the plating is tin? Nickel >>is more usual. If it is tin, is there lead, as well (solder-plated)? > > Was thinking of lugs, not wire when I wrote "Nickel is more > usual." Not true for wire. > > Best regards, > > Charles > > > > > > > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com > To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > >

J. Thanks for the pointer to Craig's post and the replies which I had in fact found earlier in the day, so I was aware of the options in that thread. However I was specifically asking for the CuSO4 and NaCl mixture, and still want to know the right proportions as I have some other stuff to strip tinning from. Thinks - will this also work with nickel plate? However another post quite rightly pointed out that I hadn't considered the issue of wicking of the etchant liquid up the wire. So: I am almost certain the cable is Def-Stan 61-12 part 5, so the wire will just be tinned copper, so I suspect my best bet will be to leave the plating in place and solder the connectors using the Sn/Cd solder (with adequate ventilation). Does that sound sensible? Dave -----Original Message----- From: volt-nuts-bounces@febo.com [mailto:volt-nuts-bounces@febo.com] On Behalf Of J. Forster Sent: 19 September 2011 18:31 To: Discussion of precise voltage measurement Subject: Re: [volt-nuts] Removal of tinning from copper wire Asked and some answers on Google: http://www.finishing.com/319/63.shtml -John ============= > ISTR from many years in my past that Copper Sulphate and Salt can be used > an etchant to remove tin and other plating from copper. Does someone > know the relevant quantities to use to make up about 100ml of etchant? > > Relevance to this list is that I have some gold flashed electrolytic > copper spades, and a suitable four core plus guard cable, but want to > strip the tinning off the wire to make low thermal EMF leads. > > I have crimp tools and also have a small amount of Sn/Cd solder I > found in an old Marconi RF meter. Which would be the better to use to > make the connection? > > PS Why do the interesting discussions about Solartron 7081 meters > happen while I'm on holiday and have suspended my subscription? > > PPS How were those leakage currents in the errant 7081 measured? If you > reply to the list about this please start a new thread. > > Thanks > Dave > > > _______________________________________________ > volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to > https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts > and follow the instructions there. > > _______________________________________________ volt-nuts mailing list -- volt-nuts@febo.com To unsubscribe, go to https://www.febo.com/cgi-bin/mailman/listinfo/volt-nuts and follow the instructions there.