Soldering with tin

[RobinParticipant @robin]

[RobinParticipant @robin]

I'm trying to buy tin so I can solder hardened carbon steel without tempering it. Apparently tin is the stuff because it melts at 272degC. If you haven't guessed my flintlocks have worn through their case hardenings.

So I bought some on that auction site. What arrived was not tin, I worked out the SG at 2.5 so I'm guessing aluminium.

I found another vendor promising me almost clinically pure tin which just arrived.

I bent it listening for the so called 'cry of tin'… deathly silence.

I tried melting it with my soldering iron and it laughed at me.

I tried melting it with a butane gas lighter and burnt my fingers.

I tried melting it with the gas hob and eventually the end fell of.

I worked out the SG at 7.6 which sounds right so I am now really confused.

Robin

[not done it yetParticipant @notdoneityet]

Tin is a tad under 7.3, so I expect it likely has something else in there…

[Brian GParticipant @briang]

Would lead-free solder be suitable, since ROHS electrical solder is normally 97% or more tin? I doubt flux cores would be much use, but perhaps Multicore PureFlow pellets which are nominally 99% tin (0.7% copper, 0.3% Silver + traces) and have an optimum temperature of 265 +/- 10. CPC Link

Brian G

[Jeff DaymanParticipant @jeffdayman43397]

DS metals in Wolverhanpton UK may be able to help with getting pure tin. **LINK**

Alec Tiranti may be able to help with tin or tin alloys. **LINK**

Your melt point number seems high – my metals handbook states MP of 239 deg C / 450 deg F

[RobinParticipant @robin]

I was weighing with the postal scale so 7.6 may be a bit of an approximation. 5m lomg 1.61mm diam 78gms

[JasonBModerator @jasonb]

CuP Alloys do several solders that melt below the 272 deg you quote for tin and even below pale straw tempering colour which is 220degC

[Robert Atkinson 2Participant @robertatkinson2]

Hi,
Standard lead free electronic solder has a melting point of around 215-227 deg C depending on alloy. (old tin / lead is about 188). The rosin flux is fine for clean steel. Available from various online sellers.

Robert G8RPI.

[Neil WyattModerator @neilwyatt]

How about lead free plumbing solder? It's virtually pure tin with a trace of copper.

**LINK**

Neil

[jason udallParticipant @jasonudall57142]

Slightly confused here.

You wish to solder using pure tin

( Lead free electrical solder is tin 97 % plus

With silver and copper…plus flux to suit

)

You wish to use low temp to protect the temper of the steel add ons

 

Now leaded based solder melts at a lower temp than lead free.

So if leaded solder( I have seen it used as tell tale for tempering) needs too much heat for your application ,the lead free or pure tin will be worse from the point of view of disturbing the temper.

There are special alloys that melt at less than even leaded solder…."magic metal" from memory..sold for PCB rework.. basically used to de-solder surface mount chips

This stuff is expensive but not silly

It's structural strength is unknown to me

Google "de-solder alloy"

Chip quick is one brand

 

Edited By jason udall on 13/12/2019 18:22:26

[JohnFParticipant @johnf59703]

Robin, You can buy it from Brownells UK gun supplies **LINK** but only in 1lb bags, however as already pointed out you will find lead free solder will work just fine with a suitable flux, the self cleaning flux for plumbers is fine but mildly acidic so you do need to wash the job to prevent problems.

John

[vintage engineerParticipant @vintageengineer]

Pewter mugs are made from tin.

[Paul LousickParticipant @paullousick59116]

Do a search for "Tin metal granules" (or similar) on ebay. I recently purchased some that was 99% pure tin which I used to make fusible plugs for a boiler.

Paul

[old martParticipant @oldmart]

As already mentioned, tin melts at a higher temperature than most tin lead solders. Using tin on its own is not free of problems:

**LINK**

[JasonBModerator @jasonb]

Any reason why you simply can't redo the case hardening? or does the metal need building up?

[RobinParticipant @robin]

Re- case hardening would destroy the antique finish. How to do this seems to have been engraved on the back of those tablets Moses brought down from Mt Sinai and they say "Thou shalt solder on a new face with tin".

Rapid have a solder cream that melts at 138C and solders at 215-260C Edsyn CR11 No-Clean SMD Solder Paste Content 10 g

I spend my life soldering which is why I am expecting this will be a real cow to do. I was rather hoping there would be something miraculous about tin. I suppose a splash of Baker's would also destroy the finish, I will need to experiment.

[Michael GilliganParticipant @michaelgilligan61133]

Posted by Robin on 14/12/2019 10:24:00:

Re- case hardening would destroy the antique finish. How to do this seems to have been engraved on the back of those tablets Moses brought down from Mt Sinai and they say "Thou shalt solder on a new face with tin".

[…]

I spend my life soldering which is why I am expecting this will be a real cow to do. I was rather hoping there would be something miraculous about tin. […]

.

I suspect that the ‘miraculous’ feature of Tin is that it is stronger, and melts at a higher temperature, than Lead.

Moses would have had no fancy alloys to choose from, so it would be one or t’other.

MichaelG.

[Andy CarlsonParticipant @andycarlson18141]

These people smelt their own and make souvenirs from them.

Homepage

Not sure if they would sell you the stuff 'in the raw' but you could ask.

Worth a visit if you are in that neck of the woods.

Regards, Andy

[Nick Clarke 3Participant @nickclarke3]

Edwards Metals in Birmingham list Tinstick (Commercial PureTin) in their catalogue on their website.

[RobinParticipant @robin]

Bravo chaps. I have ordered 100gms of 99.99% pure tin, this is in lumps rather than rods and I am fairly confident it is the real McCoy this time.

Also some Stannol liquid flux, just because it claims to be for tinning steel and isn't a solid lump like the rosin turned out to be.

I think I will experiment with new iron rather than diving in on the 200 year old expensive stuff.

This will be my Christmas entertainment

[Author]

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