Alloy by volume or by weight

[lwknight]

I always presumed that alloys are mixed by weight.
What exactly is 50/50 solder?
If you mix 1 pound of lead with 1 pound of tin you have 50/50 by weight but in reality there is a lot more tin than 50% .

For alloy recipes we always mix by weight but after a few anomalous readings from the XRF analyzer I began to think that weight is wrong.

Any thoughts?

[HollandNut]

50-50 bar solder is half lead and half tin

volume wouldn't werk

is why I keep a calculator handy and with a chart of weights of each mixture proportions ..

IOW how much tin I need for 1:20 with 1# , 2# and so on

[JonB_in_Glencoe]

I find it tough to measure a cup of molten Lead...now a cup of molten tin ain't so tough ;)

[bangerjim]

Weight......don't get lost in the weeds splitting hairs.

banger

[MaLar]

weight

[lwknight]

Does anyone know for fact that the XRF reads mass percentages instead of volume percentages?
I know that we mix everything by weight (mass)
Mass and volume are not the same thing.
So back to the 50/50 solder. It it is by weight then you cannot say that it is half tin and half lead because its actually about ( that means "more or less" ) 1/3 lead and 2/3 tin

[bangerjim]

Ever since cavemen sat around their Lee casting pots making boolits by firelight, they used weights....50/50 solder is just that. And all was good with nature. :kidding:

It has been treated that way ever since. Casters have always used the same rules of weight and cared little about density. Scientifically, mabe it is correct to do it that way.


But I do not believe anybody does. Weight is easy. Throw it on a scale......and melt it. No complicated math calcs.....just easy boolits.

bangerjim

[GLL]

The Nitron XRF analytical results are computed by calibration software and then reported as weight percentages !
Jerry

[lwknight]

The Nitron XRF analytical results are computed by calibration software and then reported as weight percentages !
Jerry

Thank You!! Finally someone gets it.

[madsenshooter]

Dutch Boy 111 is really 50/50 solder.

[RogerDat]

Sort of related - the scrap yard XrF scanner had some crud on the sensor so it kept reading a few percent of titanium and silicon. Probably from machine tool dust and lubricant in machine shop scrap.

My question is: How to remove that 5% "error" to arrive at the "true" percentage of the lead alloy?
Scanner is reporting 5% of the sample weight is the dust/crud on the sensor. So what does that do to the percentages of the other 3 elements (Pb/Sb/Sn) detected and reported as a percentage of weight?

My adjustment was to add 5% of each individual percentage. 88% Pb + 5% of 88 = 92.4

[lwknight]

I have had the same problem. I took Niton XRF reports and very carefully mixed the supposedly known alloys and had it retested to show totally irrelevant results. I have since learned that it called a "Mass Spectrometer" so that means percentage by weight. The only thing I can suggest is to have the operator do a longer scan.