Tin question

I discovered information about tin. Pure tin has a hardness of about 5, like pure lead, and that is what Rotometals sells. Lead free solder is 97% tin and 3% copper and has a hardness of 15. When you folks are adding tin to your melt, are you adding the pure soft tin or tin solder ?? I'm making a 40 to 1 alloy for .357 hunting boolits. Those boolits will be travelling about 1200 FPS out of the Handi-rifle, about the same as a 22LR so barrel leading isn't a huge concern. I have a 173 Gr. .359 GC Hammer mould coming from MP moulds for this rifle boolit.
Ohio Rusty ><>

I usually add tin in the form of pewter and only when I am having trouble with fill out in the molds.

Modern pewter is about 91 percent tin, 7.5 percent antimony, and 1.5 percent copper. I want to avoid adding the antimony as I want the boolit to remain fairly soft for expansion.
Ohio Rusty ><>

I think when talking about a 20 lb pot and adding maybe 1 pound of pewter that the percentage of antimony would not alter the hardness significantly.

I've got a good supply of 50/50 bar solder in bars. That is what I use to make up my alloy. I shoot black powder with 25/1 lead/tin alloy. I've also got some pure tin if I just want to add a little tin. I don't want any antimony so I avoid pewter.

A cousin keeps me supplied with spools of "lead free" solder which is about 95% Tin. That is what I have always used. He picks them up at auctions, usually in a box with assorted other stuff he was interested in.

That is what I have also JoeJames.... rolls of lead free solder. That is my source of tin. All my rolls of lead free solder aren't created the same. The Sterling brand is Tin and copper. One roll of Dutch Boy Is tin and copper, the other roll of Dutch Boy is tin, copper and selenium. Lastly, the Oatey brand is 95% Tin and 5% antimony.
Ohio Rusty ><>

Keep in mind that copper can be a good hardener too.. once it gets high enough.. some of the good hard babbit I have is high tin and 2-5% copper.. great stuff to spice up a batch needing some hardness.. but not brittleness.. and less weight loss than adding linotype.

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Originally Posted by Soundguy

Keep in mind that copper can be a good hardener too.. once it gets high enough.. some of the good hard babbit I have is high tin and 2-5% copper.. great stuff to spice up a batch needing some hardness.. but not brittleness.. and less weight loss than adding linotype.

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I ain't a chemist but I kind of assume that the copper forms some of the stuff you scrape off the top after fluxing.

There are a couple of pretty extensive threads about adding copper to boolits. The tin babbitt I use has such a small amount it's not worth my worry; I bought it for the tin content and it works well.
To the OPs question, there shouldn't be a noticeable difference between pure tin and tin solder if he's casting 40:1 I've used both types, mixing 20:1-30:1

As an engineer I studied copper dissolution ..its a problem on some pc board... Tin, tin lead and tin silver alloys especially can leach copper.. On a pc board with small plated rings.. You have to watch out for this.

Like I said... Tin/lead/silver will / can absorb copper. At up to 5%..its a fantastic hardener..you don't loose as much weight as say..using a linotype alloy. You can actually sweeten a pot using sacrificial copper.
For those not using a high copper composition Babbitt..its likely an invisible non issue.. Under .5% it isn't doing much other than just being there...

7.5% of 2% is only .15% of the whole. People worry way too much about exact alloy composition.

50/50 Bar Solder has always been the easiest form of Tin for me to obtain .
I'm not sure what exactly the composition is ... but it has worked well to make simple tin - lead alloy .
I wouldn't get all hung up on having perfectly pure tin and perfectly pure lead...
... it's realy not that important .
Gary

For making up 16 to 1 lead/tin alloy for 45-70 bullets I buy a pound of tin from rotometals and blend it with pure. For making batches of my other casting alloys I usually use lead free solder because I've been able to acquire it from time to time at low cost. I won't turn up my nose at 50/50 bar solder, linotype, or pewter though, because 90% of getting casting metals is scrounging. I've found that the key is to amass a horde of materials over time, ie: clip-on wheel weights, superhard, tin based alloy, scrap lead, etc., then melt up the whole lot and cast it into ingots. That way I end up with hundreds of pounds of casting alloy that's all of the same composition and properties. I usually make this alloy on the hard side for rifle bullets, with a tin/antimony/trace of arsenic content that it can be cast either air cooled, or water quenched. The benefit of having a lot of rifle alloy is that I can cut it 50/50 with pure for pistol bullets. Long story short; for me, tin from any source is welcome.

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Originally Posted by 405grain

For making up 16 to 1 lead/tin alloy for 45-70 bullets I buy a pound of tin from rotometals and blend it with pure. For making batches of my other casting alloys I usually use lead free solder because I've been able to acquire it from time to time at low cost. I won't turn up my nose at 50/50 bar solder, linotype, or pewter though, because 90% of getting casting metals is scrounging. I've found that the key is to amass a horde of materials over time, ie: clip-on wheel weights, superhard, tin based alloy, scrap lead, etc., then melt up the whole lot and cast it into ingots. That way I end up with hundreds of pounds of casting alloy that's all of the same composition and properties. I usually make this alloy on the hard side for rifle bullets, with a tin/antimony/trace of arsenic content that it can be cast either air cooled, or water quenched. The benefit of having a lot of rifle alloy is that I can cut it 50/50 with pure for pistol bullets. Long story short; for me, tin from any source is welcome.

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Old tin/lead solder is great regardless of ratio. For your 16 to 1, 15 pounds of lead and two pounds of 50/50 solder is just the same as 16 pounds of pure lead and 1 pound of pure tin.

I got 40 pounds of bar solder at the scrap yard for a $1.25 a pound like their other lead scrap. Woo Hoo [smilie=w:

You guys that have scrap yards and metal recyclers that sell to you that must be amazing down here in Florida scrap yards and metal recyclers by but will not sell you can walk in there and they'll have 55 gallon drums of wheel weights and solder and Lead sailboat Keels and they'll just be sitting there and all you can do is look at them

40 to 1, means the 1 portion is 2.5% of the final product. A single digit percentage of 2.5% is miniscule, probably almost insignificant in effect. If you find otherwise please let us know.

I’ve been using dinnerware type pewter for my 16 to one mixes with “pure lead” flooring. When I first got started here about five years ago I mix 16 to one and I only ended up with a 7.5 BH. Which is basically 40 to 1 alloy hardness which I have learned from experienced members here. Now that I’ve been casting for a few years I only use modern dinnerware pewter that I melt into ignots. If I remember right the average BH i test with them is around 22 for harness. It took an eight to one mix to get it to a true 16 to one alloy hardness of 11 BH when I made it a few months ago. At that rate I might as well mix 50-50 pure lead and COWW since I end up at 10.5 BH since it is about the same hardness. On my test media Boolits seem to hold together and expand about the exact same at the same given velocity. It’s also a lot cheaper for me to mix 50-50 than to run out and look for pewter non stop. I’m sure the 16 to one alloy is probably going to be tougher and whole better together and more mailable in the long end.

FYI I did test my old pewter ignots back when I casted up the original 16 to one back five years ago and my “pewter” ignots I smelted were only 7.5 BH by themselves to begin with so it can never get harder than that obviously. I didn’t know what I was doing and melted a lot of what I thought was pewter and had more lead in it which made it softer. If you stick to dinnerware items as the experience guys here advise you’re gonna get closer to that 20 to Burnell hardness mark like I did. Still took twice as much ratio to get to 16 to one for me. I’d suggest to get a lee hardness tester like I did and that way you know what your actual hardness is.

Think think BH is all over the board as far as harness goes. I thought it was around 40 and when you Google it it says 51 to 75. Who knows… that’s why you need a tester so you can mix the hardness you’re trying to accomplish. Without a tester you will never know what your alloy hardness is and every time you mix up another batch imo it will never be the same hardness. Also your group size is going to change when your hardness varies. If your shooting minute of pop can at 25 yards who cares. If you want consistent hunting accuracy I’d invest in a $60 lee hardness tester.

I do still have a good supply of the original 7.5BH alloy boolits. I casted them up in a Lyman devastator .430 mold. I get sub MOA accuracy at 100 yards in my 77/44. I do GC and PC them. My best accuracy comes at 1600 fps. I’ve tried that alloy all the way up to 2100 fps out of my 336 PC and GC with no leading. Accuracy at 2100 fps was around 2” or a hair less at 100 yards. I went with 50/50 pure and COWW that shot all in the same hole as you can see in my avatar. At slower your speeds I’m sure the softer 40/1 will work excellent. Last day of doe season here. Going to try and get out to test a 40/1 HP at 1600 fps on a whitetail today.

Tripplebeards: I hope you get a fat buck that's full of steaks & sausages. :)