How to identify solder

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  • Last Post 24 May 2016
cbshtr posted this 18 May 2016

I have been gathering up solder from yard sales and other places so I have a source of tin to help with bullet fill out. Some of the spools are marked and some aren't. Most are standard thickness, some are real thin and others in between the extremes. My plan was to melt them all together and cast some 45-405gr bullets so I could add a predetermined amount of bullets per ingot or ingots of my casting alloy. If i knew the content of each spool I could calculate the approximate percentage of tin in the overall mix. I have used solder in the past in heating and air conditioning but we used mostly silver so there was no mistake of using lead in a drinking water connection. I was just hoping that maybe someone out there had a trick up their sleeve to figure out how to determine what each roll of solder was made up of. I know it's a shot in the dark but I figured it can't hurt to ask.

Robert Homan

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Brodie posted this 19 May 2016

Virtually all solder for water connections is leadless.  It has a high percentage of tin.  Older solder is a lead tin mix.

You could melt it all together and cast it into bullets or ingots and send a sample to Roto- -metals to get an analysis. You could also take the “ingots” to a metal scrap or recycling yard that has a XRF Gun

In either case I personally would melt them all together so that you only had one sample with a known percentage of metals, and could calculate accordingly. Congratulations on your foresight and good luck with your project. Brodie

B.E.Brickey

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Myflatline posted this 20 May 2016

What about Rosin core solders? Not all have labels and for the most parts have dried out. If melted down outside and fluxed , would that create an issue?

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Brodie posted this 20 May 2016

Rosin core solders are simply solder with an inner core of FLUX.  What you should worry about are ACID core solders.  These were used for soldering copper pipe and such and the acid was there to clean the metals while you soldered.  The only issue these pose is the fumes when they are melted.  Smelt them out of doors and keep up wind.  If you do it on a breezy day unless you have a great amount of acid core solder it should be no problem.  Brodie

B.E.Brickey

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Myflatline posted this 20 May 2016

Thank You.  I have a box full from yard sales and such.

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cbshtr posted this 24 May 2016

Good to know about that rosin core solders are okay to use after melting down. I melt outside so the fumes aren't a problem. I did see one coil was 95% tin. I pretty much cast with a mixture of acww and range scrap. I used to separate the jacketed from the all lead bullets but it takes a lot of time and I'm not sure if there is that much of a hardness difference between the two. I have a really hard time getting complete fill out so I'm hoping that the addition of tin will shorten my casting sessions.

Robert Homan

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Brodie posted this 24 May 2016

cbshtr, Rosin core fumes can be lit on fire.  Acid core is just best left to diffuse down wind.  You could try casting a little hotter and faster; it will give a bit better fill out. Brodie

B.E.Brickey

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Myflatline posted this 24 May 2016

Yep, I found that out yesterday.  Bellows black smoke too.  But now I have a bunch of little hockey pucks to use.

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