Tin additives

[Sasquatch-1]

Does anyone remember when the casting books said to use old toothpaste tubes to add tin to the mix? When I started back in the seventies I tried this but they had already changed the composition of the tubes away from tin.

[Grandpas50AE]

I remember, but by the mid-to-late 60's, the toothpaste tubes had already changed to something other than tin and I didn't start casting until 1973. But I do remember growing up with those tin toothpaste tubes.