40/60 SnPb Solder OK for making Stannous?

[Brett Novak]

not sure if the lead would mess up the solution??

Thanks in advance

 

[orvi]

It is possible that lead chloride start to crystallize/precipitate out of solution as it saturates - as PbCl2 does not have that great solubility in water or even HCl. But as long as you would have Sn in solution, it should be OK.
Cannot you purchase small roll of lead free tin ? It is used nearly everywhere, small roll cost few bucks and you don´t need more than 10g for start.

 

[Yggdrasil]

not sure if the lead would mess up the solution??

Thanks in advance

As Orvi said, it will probably work, but to me it seems way more toxic than it have to be.
Where did you find 40/60 Sn/Pb solder these days?
Ordinary solder for electronic or general purpose soldering will do fine.

 

[Brett Novak]

Thanks Guys - Ok I'll go raid the lab again and grab some lead free.

I work in electronics, so we still have leaded stuff around for prototypes, etc. I have to look in my plumbing kit at home, I may have some lead free stuff in there.

 

[Brett Novak]

found some thick 90+% tin solder in my workbench.

Question is, how long do you guys usually simmer this in HCL for? I put 15g in 100mL of HCL and simmered for an hour. Is that enough?

I don't have any pregnant AR solution at the moment but I put some on gold pins and got nothin' - does stannous not work on solids? (sorry if that is a really dumb question!)

cheers and happy weekend!

 

[Shark]

I place the solder and HCl in a bottle and run hot tap water across the loosely capped bottle until I see a reaction on the solder. Maybe a minute at most. I start using it at that point.

And no, it does not work on solids.

 

[Brett Novak]

Thanks Shark!

I ended up using about 15g of tin solder and 100mL distilled water and 150mL of HCL, simmered for an hour, and it appears to be working! Hooray! and I have 200mL of stannous! my official test kit gets here tomorrow so I'll do a side by side

 

[FrugalRefiner]

Keep in mind that stannous solution has a limited shelf life. I usually only make 15 ml at a time.

Dave

Edit to correct: stannous solution

 

[Yggdrasil]

Keep in mind that Shannon's solution has a limited shelf life. I usually only make 15 ml at a time.

Dave

A slight case of autocorrect maybe?

 

[FrugalRefiner]

Yes indeed. It did it again when I added the edit note. It also likes to change Yggdrasil to Aggression.

Dave

 

[Yggdrasil]

Yes indeed. It did it again when I added the edit note. It also likes to change Yggdrasil to Aggression.

Dave

 

[orvi]

Thanks Shark!

I ended up using about 15g of tin solder and 100mL distilled water and 150mL of HCL, simmered for an hour, and it appears to be working! Hooray! and I have 200mL of stannous! my official test kit gets here tomorrow so I'll do a side by side

Stannous chloride usually degrade via two pathways.

First is when air is introduced. Air contains oxygen, and oxygen reacts with stannous chloride (SnCl2) and oxidize it to stannic chloride (SnCl4). Tin in the oxidation state +II is the one you need to reduce gold and create that specific stain. Sn +IV does not work as it is already oxidized. So the advice No.1 = do not let the oxygen into contact with solution, meaning store in tight containers and always check with standard gold solution, if it is working. Gold does not deteriorate, stannous does.

Second pathway is when acidity is low. If you will ever dissolve stannous chloride crystals in pure water, stannous (SnCl2) will hydrolyze to hydrated tin hydroxy-chlorides, which are insoluble and precipitate as white cloudiness/solids out of solution. Typical SnCl2 is sold as dihydrate, which is most of the times already partially hydrolyzed and produce milky solutions when dissolved in water/diluted HCl.
Due to this, it is best to maintain some HCl level to prevent rapid deterioration. I personally use like 5-10% HCl to make stannous from tin chloride dihydrate powder I have on hand. You can also dissolve tin in excess of HCL and use it that way.