Alloy mix question

[steg]

My question is when an alloy mix calls for say 20 to 1, just what is that 1 part composed of, is it something like 60/40 or is it actually pure tin?...........steg

[sagacious]

The 20:1 denotes a ratio with the lead first, and tin second. The 1 is pure tin.

Tin/lead solders are usually given as a ratio with the tin first and the lead second, such as 60/40, which is Sn60 and Pb40.

[fredj338]

The 20:1 denotes a ratio with the lead first, and tin second. The 1 is pure tin.

Tin/lead solders are usually given as a ratio with the tin first and the lead second, such as 60/40, which is Sn60 and Pb40.
Yep, so 20-1 would be say 20oz of lead & 1oz of tin. A 1# bar of 60/40 solder would be 9.6oz lead & 6.4oz tin. So if my math is right (never a guarantee) that would be about 2 5/8"oz of solder + 18.5oz of lead (approx)?:confused:

[lwknight]

A 20 to 1 totals 21 parts. 60/40 is the percentage of each part that totals to 100%.
A 5% tin to 95% lead can be considered by most as 20-1 , although not exactly correct.
A true 20 to 1 is 4.75% tin and 95.25% lead. Not a big difference.

[steg]

Thanks for clearing that one up for me guys!...............steg

[sagacious]

Yep, so 20-1 would be say 20oz of lead & 1oz of tin. A 1# bar of 60/40 solder would be 9.6oz lead & 6.4oz tin. So if my math is right (never a guarantee) that would be about 2 5/8"oz of solder + 18.5oz of lead (approx)?:confused:

Easier to keep the calculation all decimal.
16ozs of 60/40 solder is 9.6ozs Sn and 6.4ozs Pb (16x.6=9.6).
2.625ozs (2-5/8ozs) 60/40 solder contains 1.575ozs Sn (2.625x.6=1.575)
So you'd need to add 30.45ozs lead to 2.625ozs 60/40 solder to get 33.075ozs of 20:1 alloy.

Here's a slightly easier way to look at the numbers:

1.75ozs of 60/40 solder contains 1.05oz of Sn (1.75x.6=1.05). Let's call that 1 part Sn.

20 parts lead would be 21ozs of Pb (1.05x20=21).

Subtract from 21 the .7ozs of lead that is in the 1.75ozs solder, and you get 20.3ozs lead + 1.75ozs 60/40 solder = 22.05ozs of 20:1 alloy.

[skimmerhead]

sagacious you the MAN! now thats so simple a cave man could do it!!!!! thanks

skimmerhead:veryconfu

[Caveape]

Hey now!
I resemble that remark!
:lol: