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I normally use 145C solder for my modelling, and usually buy small coils of it off e bay etc.
The only info the packets usually have on is that the solder contains Cadmium.
Im looking at buying a 500 gm coil to save buying lots of small ones. The solder in question is 145C and its constituents are 50% Tin, 32% Lead and 18% Cadmium.
I'm after help - does anyone know if this is the ideal formula and I hope its the same as the small coils that I have been buying - I dont want to spend £60 and find it isn't, so any help appreciated!!

Many thanks,

Andy.

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Looked at Carrs and it says tin & lead but contains cadmium, as does another make on eBay, may be a standard composition

 

Its classed as detail solder, some even classify it as low melt, I normally use around 180 degree wire, in fact I am about to try 221 degree for basic etch soldering, it has 2% silver and has been recommended along with 180 degree with 2% silver for main construction, then using 145 for detail parts near solder joints  

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As a semi-non-scientific answer, 18% cadmium looks very high.

 

I am sure it will work, indeed cadmium is often praised for improving flowability.  It is however very toxic.  Lead is quite nasty but cadmium is to be avoided if possible.  At 320 degrees C it is likely to convert to volatile cadmium oxide.  A lot higher than 145 degrees except that your iron is likely to be running at 300 C plus.  If you don't have temperature control you could easily exceed the 320 degree point.  Breathing in cadmium fumes seems to be universally regarded as about the worst way of getting cadmium poisoning.

 

So in the absence of the Carrs and similar products compositions which are designed specifically for our use, I would be wary. 

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Thanks for the replies so far - does anyone make a 145 solder that's Cadmium free or is it essential to have Cadmium in to get such a low melt, as I understand that it helps lower the melting point and also the flowability.

 

Andy

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It's Wikipedia, so take with caution and probably incomplete, but it does list various lead/tin/cadmium alloys with 18% cadmium for 145 solder.

 

https://en.m.wikipedia.org/wiki/Solder_alloys

 

lead/tin/bismuth and indium/silver appear to have similar melting points but I have no idea of their compatibility with modelling materials and common fluxes.

 

 

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58 minutes ago, Andy Hardman said:

Thanks for the replies so far - does anyone make a 145 solder that's Cadmium free or is it essential to have Cadmium in to get such a low melt, as I understand that it helps lower the melting point and also the flowability.

 

Andy

 

Andy

 

Most would call 70 degree low melt solder. also 100 degree which apparently does not require tinning brass when soldering it to whitemetal, neither are listed as having cadmium unlike 145 degree solder 

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Maybe ask Eileens.

 

They sell 145 in large quantities which is recommended for railway modelling. I also doubt they would be selling anything extremely hazardous without a warning.

 

https://eileensemporium.com/index.php?option=com_hikashop&ctrl=category&task=listing&cid=1124&name=straight-wire&Itemid=189

 

Also a bit cheaper at £50 for 0.5KG.

 

 

 

Jason

 

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3 hours ago, Steamport Southport said:

Maybe ask Eileens.

 

They sell 145 in large quantities which is recommended for railway modelling. I also doubt they would be selling anything extremely hazardous without a warning.

 

https://eileensemporium.com/index.php?option=com_hikashop&ctrl=category&task=listing&cid=1124&name=straight-wire&Itemid=189

 

Also a bit cheaper at £50 for 0.5KG.

 

 

 

Jason

 

Many thanks for your help Jason,

Just ordered some. 

Cheers,

 

Andy

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On ‎14‎/‎01‎/‎2020 at 21:16, hayfield said:

Looked at Carrs and it says tin & lead but contains cadmium

 

I've got some Carrs 145 degree solder and it states 'cadmium free' on the packet.

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On 15/01/2020 at 08:03, Andy Hardman said:

Thanks for the replies so far - does anyone make a 145 solder that's Cadmium free or is it essential to have Cadmium in to get such a low melt, as I understand that it helps lower the melting point and also the flowability.

 

Andy

 

There are 145deg solders containing Bismuth and no cadmium:

 

https://www.ebay.co.uk/itm/500g-138-145-C-low-temperature-SMD-desoldering-alloy-bismuth-solder-Bi58Sn42/153712833547?hash=item23c9ffb40b:g:6nMAAOSwQ69dwk0t

 

According to Wikipedia (yes yes I know...)

 

Quote

Bismuth significantly lowers the melting point and improves wettability. In presence of sufficient lead and tin, bismuth forms crystals of Sn16Pb32Bi52 with melting point of only 95 °C, which diffuses along the grain boundaries and may cause a joint failure at relatively low temperatures. A high-power part pre-tinned with an alloy of lead can therefore desolder under load when soldered with a bismuth-containing solder. Such joints are also prone to cracking. Alloys with more than 47% Bi expand upon cooling, which may be used to offset thermal expansion mismatch stresses. Retards growth of tin whiskers. Relatively expensive, limited availability.

 

Also under Impurities, it states:

Quote

Cadmium – causes sluggishness of solder, forms oxides and tarnishes

 

Edited by 57xx

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