Sciencemadness Discussion Board

Solvent for tin-lead solder

Romix - 2-7-2015 at 16:47

Recommend me solvent to dissolve solder.

smaerd - 2-7-2015 at 17:01

????

Volanschemia - 2-7-2015 at 17:09

Not really sure what you're talking about here.

You can't "dissolve" solder, not in the way you would do it with salt, because it is an alloy.

If you are talking about dissolving it in an acid, then that makes a bit more sense. Is this the case?

Molecular Manipulations - 2-7-2015 at 17:28

Quote: Originally posted by Romix  
Recommend me solvent to dissolve solder.

Mercury would do it most likely.

violet sin - 2-7-2015 at 18:52

funny, just yesterday while cleaning I ran across a ziploc bag I marked so it wouldn't toss( from 4 years back). "Sn/Pb solder, not in trash" I found it easy to get the tin out if that's what you want( kinda pure). take some of the solder, put it in a piece of coffee filter as a catch bag, with one tip hanging out above the solution or better a stainless wire going in to the wad. attach to a power supply as the anode, with some dilute HCl. could use copper cathode if you don't have stainless wire, to grow from.

https://www.youtube.com/watch?v=Af9GAUYDrlQ
like this ^^^ but starting from HCl sol instead of SnCl solution.

lead is somewhat soluble here so the solution shouldn't be tossed down the drain. this means the tin also won't be pure, as some lead will make it to the other side.

you could try with the solder in dilute sulfuric acid instead which would lock the lead out as the insoluble sulfate. but I haven't tried this. so it may coat the solder in lead sulfate and choke out the flow of electricity.

if you are going to play with lead salts/solutions, be prepared to be responsible with your mess. no one here want's to hear about heavy metal residues getting disposed of improperly, ok.

I still have all of mine, and will be electroplating out the crud when I get enough together.

blogfast25 - 3-7-2015 at 06:35

The only thing that will dissolve Sn/Pb quickly is Aqua Regia (doesn't have to be concentrated), to Sn(+4) and PbCl2 (a bit of which will be in solution).

Subsequent separation of the two is relatively easy.

annaandherdad - 3-7-2015 at 16:24

Quote: Originally posted by violet sin  
funny, just yesterday while cleaning I ran across a ziploc bag I marked so it wouldn't toss( from 4 years back). "Sn/Pb solder, not in trash"


Do you use lead-tin solder because the lead free kind is too much of a pain to use? I find it very difficult to work with.

Romix - 3-7-2015 at 17:31

Quote: Originally posted by annaandherdad  
Quote: Originally posted by violet sin  
funny, just yesterday while cleaning I ran across a ziploc bag I marked so it wouldn't toss( from 4 years back). "Sn/Pb solder, not in trash"


Do you use lead-tin solder because the lead free kind is too much of a pain to use? I find it very difficult to work with.

Both lead - free and lead - tin.

Romix - 3-7-2015 at 17:34

Quote: Originally posted by TheAustralianScientist  
Not really sure what you're talking about here.

You can't "dissolve" solder, not in the way you would do it with salt, because it is an alloy.

If you are talking about dissolving it in an acid, then that makes a bit more sense. Is this the case?


Yes, dissolving in acid, can be done in base, but heating to over 100C needed, NaOH for example etches lab glass, and after it cracks like sodium glass, temperature changes etc...

And base will also remove paint that protects copper lines from oxidation, so that it can be washed off afterwards.


[Edited on 4-7-2015 by Romix]



[Edited on 4-7-2015 by Romix]

violet sin - 3-7-2015 at 19:23

@ annaandherdad : It was the only solder I had at the time, that contained Sn. more recently though- https://www.sciencemadness.org/whisper/viewthread.php?tid=30...
the Pb free stuff didn't like my copper much. Nice and clean surface, used ZnCl2- still it didn't always flow nice. Had a few spots I needed to re-scuff, pile on ZnCl2 and hope for the best. It took 4 tries to get the leaks sealed all the way. But the sprinkler works great now :)

Zinc chloride SURE likes water, good lord. now the top layer is damp from just opening it a few times.[Penny extractions, lol, scuff and soak in HCl. try like hell to dry it and seal].

---------------------------------------

back on track here, as a quick check, I put a ~ 0.25g crystals of CuCl2 in ~5ml of H2O and added ~4-5 drops of HCl. after getting most of the copper chloride dissolved, I added about 2cm of fine 99.5% Sn/Cu electrical solder. the solution went clear in ~5 min and left a black/copper colored spongy mass where the solder was. viola, Sn in sol... in just a few min without nitric acid.

this occurred to me because I had just read about getting Zn into H2SO4 sol. apparently just plain Zn in strong sulfuric is not the wise way to go about it. got a little frustrated as it was just over a hundred degrees out back. google thnx, read about using CuSO4 or Cu metal as a catalyst, though had to dilute my acid sol quite a bit, shezam. ZnSO4

edited for poor wording from time constraints

[Edited on 4-7-2015 by violet sin]

blogfast25 - 4-7-2015 at 07:50

Quote: Originally posted by violet sin  

back on track here, as a quick check, I put a ~ 0.25g crystals of CuCl2 in ~5ml of H2O and added ~4-5 drops of HCl. after getting most of the copper chloride dissolved, I added about 2cm of fine 99.5% Sn/Cu electrical solder. the solution went clear in ~5 min and left a black/copper colored spongy mass where the solder was. viola, Sn in sol... in just a few min without nitric acid.



That's quite interesting actually. It would also allow separating tin and antimony from pewter. One thing that chemically distinguishes these two is that antimony(III) is precipitated from solution by copper (metal) but tin(II or IV) is not.

Dissolving pewter in a cupric salt solution would yield a tin(II) salt, with the Sb neatly deposited on the formed copper.

In the case of a lead solder the lead would not dissolve.

[Edited on 4-7-2015 by blogfast25]