Aluminum tuner button question

[Richard500]

My current repair has aluminum tuner buttons on brass shafts. I have another antique that has aluminum on steel shaft. Seems to be common on antiques.
I’m assuming that the buttons are cast directly on the shafts and do not remove, and that they are what we’d call un-alloyed aluminum, not pewter or some other alloy. Anybody know?
I’m asking because there is going to be some heat involved and I’d rather not melt the button.

[dhergert]

All I can tell you, related to the aluminum instruments that I have, is that older aluminum alloys are very soft compared to today's aluminum, so you'll want to be extremely careful to avoid melting things. My early 1930s Alcoa double bass had some aluminum welding repairs attempted that surprised the modern-aluminum-familiar repair person by melting down... And a patch had to be applied. Fortunately the patch is solid and stable, but it's sort of sad that the meltdown occurred.

I believe the old 1930s alloy in this case was numbered 2000 or something like that. Today's typical aluminum melting point is around 1200F, judging from the meltdown scars inside my double bass I'd guess ~70%-80% of that for the old alloy, but, you'd be best off having a way to test this.

Mandolin Cafe' user J. Condino has significant experience with old aluminum instruments. I'd highly recommend that you reach out to him for better details.

[Jim Garber]

Are these tuners on an old Weymann bowlback mandolin perchance. Like these:

[Richard500]

Jim, no; Oscar Schmidt 12 string, both types. OS have serial numbers, and mine are only about 200 units apart, so an interesting change of material on the plates close in time. I don’t know if there’s a year code - first two digits, maybe. Also not covered, like your Weymann. And worm-over.
I also think the fretboard dots are aluminum too. It is possible that these were made in Germany according to this forum. There are no interior labels.
Factory made, but astoundingly substantial sound in the low end, and unwarped by all those strings and decades. I’m thinking triple strings wasn’t just a gimmick.

[MikeEdgerton]

Before the advent of cheap and bountiful electricity Aluminum was a precious metal akin to gold or silver. I don't know where it stood at the time these tuners were made but it's value a few years earlier was healthy.

http://www.americaslibrary.gov/jb/gi...onument_3.html

[Richard500]

@Mike. True, the watershed year was 1886 for the Hall process, and the metal became rapidly cheaper and available. By the time the Wright brothers cast their engine, say about 1900, Al was down to $0.30/ pound and no longer exotic. The appeal for tuners was likely that they weren't going to come off, and were light.
Right now we’re likely in the carbon fiber growth years, as an exotic material filters down to hundreds of new applications. Some of us are expecting graphene to blossom next...

[sblock]

Yes, the top of the famous Washington Monument in DC is capped by a 9-inch pyramid made of solid ... aluminum! In the early 1880's, aluminum cost over a dollar per ounce (about $30 today, adjusted for inflation) and was mainly used for jewelry.