Mono vs Foundry type

[yovinny]

Did anyone ever find a definitive way to tell Monotype from Foundry type ?

There was also question about the letter spacers,, and if those were a different composition from either type.

Any new info on these in the last hand full of years ?
I tried searching, but came up with the same old threads....TIA
Cheers, yv

[Conditor22]

The most definitive way is to test the hardness.

to my understanding, monotype and foundry are only used on the single letters/ symbols. If a letter block will be used for a long time they will go foundry which is harder than monotype

spacers can be any alloy but usually softer than linotype

monotype/foundry

[Martin Luber]

Does monotype cast poorly? I had melted a bunch of what I thought was linotype and it acted like zinc, wadded up in the top of the pot and wouldn't pour well.

Thoughts?

[farmbif]

put a drop of acid on it and see if it bubbles up or just sits there

[farmbif]

send a piece off to someone with an xrf for analysis

[Conditor22]

monotype/foundry melts at a lower temperature and due to the tin content casts like a dream. IF you get the pot to hot it will even migrate into the vent lines giving you a row of hairs on both sides of the boolit

[garandsrus]

Type metal can have an oatmeal consistency on the top when you melt it. Adding A fair amount of flux will take care of it.

[Dusty Bannister]

That foam like cap on the melt is from a high percentage of antimony. Heat and it will go into solution.

[earlmck]

Foundry type has significantly more tin/antimony than monotype so will cast a harder but lighter boolet. According to my info on alloys, if your normal boolet cast of wheelweight metal (96.5/0.7/2.8 of Pb/Sn/Sb) weighs 100 grains then the same boolet cast of foundry metal (62/15/23) will weigh 86 grains while cast of monotype (72/9/19) it will weigh 89 grains. I've never cast a monotype boolet but I once cast some of foundry metal that I had thought was linotype. Shot very poorly and was so brittle/hard the boolets would shatter when pounded with a hammer. But foundry metal cast beautifully.