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View Full Version : interesting 'stops' in the pursuit of tin



ktw
05-02-2007, 11:53 AM
I dropped by my local salvage yard recently to top off my supply of roof flashing. While there I asked him about Linotype/monotype. Nothing. Then I asked him about Tin.

He did have this pile of stuff that he claimed had high tin content, but couldn't tell me much more about it other than that it was pipes form an old pipe organ. I bought a couple of pounds to play with.

I melted it down today in the smelter. It melted very quickly, much faster than pure lead. I will do a temperature test later today in my casting pot, along with trying it straight for a few test bullets.

The ingots look alot like the 60/40 from the radiator shop that I smelted about a year ago (frosty). I did a quick hardness test on it and arrived at 16.5 bhn with a Lee tester about a half hour after pouring it (this was on a big drip of about 200 gr in size, not an ingot).

Wikipedia has the following to say about pipe organ pipe construction:

Organ pipes are generally made out of either wood or metal. Metal flue pipes are usually made of varying mixtures of lead and tin, depending on the requirements sought for that particular pipe. The more lead used in the alloy, the darker the resulting tone will be. Conversely, if a pipe has a high proportion of tin, it will have a brighter tone. In addition, high amounts of tin give a gleaming and long-lasting polish, which may be desired if the pipe is clearly visible. Pure lead is too soft to be used alone; stiffening agents such as antimony and copper must be added for increased rigidity. The cost of each metal is also a factor, with tin being of far greater expense than lead. The usual exceptions to tin-lead alloys are very lowest pipes in a rank, which are sometimes made of rolled zinc. In addition, pipes have been made of many metals, including gold, silver, aluminium, brass, copper, and iron.

If anyone else has used this material before, or has additional tests that I could perform to help arrive at a ballpark tin content I would appreciate hearing about it. If it casts clean test bullets I plan to use it as a WW sweetener, but a better idea on content would help me determine a good price for buying more of it.

-ktw

Pilgrim
05-02-2007, 01:04 PM
An article in Handlader/Rifle some time back provided a method of determining the constituents of alloys. It consisted of casting a pure lead boolit and then casting one of your alloy from the same mould. Depending upon weight & dimensions, there was a lookup chart/graph that provided the percentages of each (lead, tin, antimony). That's the best I can do for you right now. My Handloader/Rifle magazines are all stored at the present, so I can't get the article for you. I did try the method against what I believed my alloys to be and the method provided answers that came out very close to the expected ratios. Perhaps somebody on this board has the digital files (DVDs) and can look the article up for you. FWIW...Pilgrim

Leftoverdj
05-02-2007, 01:22 PM
I looked into it sometime back. The possibility of zinc pipes scared me off.

fourarmed
05-02-2007, 04:13 PM
"The Art of Bullet Casting" is available from Wolfe publishing, and has that article in it. It will give you a rough idea. However, it is not going to give you the sort of measurement that it claims to. It is easy to calculate the ratios to lots of decimal places, but it is just about impossible to get the required measurements accurate to the level of precision necessary to make it work. Ever hear of the scientific term "significant figures"? (And I'm not talking about Carpetman's avatar.)

Whitespider
05-02-2007, 07:44 PM
I have an uncle, who has a friend (I know, I know) that rebuilds old pipe organs for a hobby. It is my understanding that the “best” pipes are made from lead and tin with a tin content of 50% to 60%. Both those guys are strong “anti-gun” (uncle from mom’s side of the family) so they’re not about to give me any to use for bullets.

ktw
05-03-2007, 01:05 AM
An article in Handlader/Rifle some time back provided a method of determining the constituents of alloys. It consisted of casting a pure lead boolit and then casting one of your alloy from the same mould. Depending upon weight & dimensions, there was a lookup chart/graph that provided the percentages of each (lead, tin, antimony).

If anyone has access to the article mentioned above, here are the numbers I generated today.

Boolit ......... Alloy ...... Diameter ........ Weight
454190 ...... Pure ........ .4524 .......... 259.02g
454190 ...... WW ......... .4535 .......... 254.31g
454190 ...... Pipes ....... .4552 .......... 238.80g

280468 ...... Pure ........ .2832 .......... 114.60g
280468 ...... Pipes ....... .2846 .......... 106.02g

I also ran the cool down test and 450*F was the point where the temperature change stalled as the melt solidified.

This appears to me to have a lot of tin in it. It filled out in the mold much better than WW alloy. Based on the tests done so far it it appears to me to be something fairly close to 60/40 solder.

-ktw

Pilgrim
05-03-2007, 12:11 PM
I checked the table for the measurements you provided and interprolated between the ratios in the table as your alloy falls in between two of the ratios provided. It indicates that the alloy you have is in the vicinity of 80% lead, 9% tin, and 11% antimony. I checked the reverse calculation using the method to see what a 60% tin 40% lead boolit would be predicted to weigh and it was about 203 gr. Calculating the reverse ratio alloy (60% lead, 40% tin) indicates that a boolit would weigh about 222 gr. Being confused re: melt temperature you were getting vs. alloy indicated, I looked further in the Lyman Cast bullet Handbook. If you have that book, go to page 47 and study figure 5. Using that figure and the explanations for it I checked to see where a 80 - 9 - 11 alloy would melt. The figure indicates that the alloy would begin to melt at 460 degrees, so it is possible that your alloy actually is 80 - 9 - 11 and your thermometer is off by some 10 degrees or so. Since most of our standard measureing devices are +/- 10% (at best) your thermometer could be off by as much as 45 degrees (either way) when it reads 450. Based on your data and my research using the limited resources I have readily available, I'd say that your alloy is actually the 80-9-11 indicated by the Wolfe article. Pilgrim

ktw
05-03-2007, 02:15 PM
Pilgrim;

Thank you very much for the info.

80-9-11 works out to something like Linotype, but with twice the tin content?

I understand your thermometer comments, but this one was from the Antimony Man and he advertises them as +/- 1% within the range of 200-1000*F. Whether it is that precise or not is another question...

This has moved from a fairly simple alloy question to a more involved research topic. Man I love casting bullets.
:-D :drinks: :-D

Given that it's the beginning of shooting season here I'm going to drop the topic of mystery alloys for the time being. The organ pipes can sit at the salvage yard just as well as they can in my stash. I have ordered the Art of Bullet Casting DVD from Wolfe Publishing. Next winter I will schedule a series of cool down tests and as-cast diameter/weight tests with all my alloys, to satisfy my curiosity more than anything else.

Thanks again for the help.

-ktw

w30wcf
05-03-2007, 10:27 PM
ktw,

A friend of mine was in the business of making organ pipes for 30+ years before he retired. He always used 50/50 tin/lead alloy because it made the best pipes.
He purchased his material from a source that certified the alloy to be 50/50.

w30wcf

garandsrus
05-04-2007, 12:07 AM
ktw,

I have an article that shows how to determine the alloy composition based on specific gravity. Basically, you weigh the boolit on a balance beam scale while it is hanging from a thread under the pan and Then, you weight it again while it is submerged in water.

The difference in the weights is used to compute the specific gravity. You then lookup the composition in a table. Unfortunately, there are usually several different mixes of tin and antimony that have the same specific gravity. However, in the case of the pipe organs, there probably isn't any antimony based on what you have researched.

If you want a copy of the article, PM your email address to me.

John