Is this Monotype or ???

[Ugly Dwarf]

I got a bucket (120+ lbs) of "monotype" from someone I recently met. I was on my way to the scrapyard to pickup some wheelweights and I brought a few pieces along.

The scrap yard has a spectrometer (I think that's what it's called) that will tell them the chemical makeup of a given alloy, and they offered to scan the pieces for me.

Of the three pieces I tested, they came out to be the following composition of Lead, Tin and Antimony (all percentages rounded). 1: 65%, 7%, 28%; 2: 81%, 7%, 12%; 3: 68%, 13%, 18%. I didn't write it down, but I believe he said there were trace amounts of copper in one or more pieces.

Any thoughts on what kind of metal this is? Any problems casting bullets with trace (less than 1%) copper in the melt?

My plan is to smelt it all together (I have to assume that the MANY other pieces will be of random percentages in that range) and then have him test a bar of my new alloy the next time I pick up WW's.

Any thoughts on my plan?

Thanks for the input.

Dwarf

[garandsrus]

Dwarf,

You got a good deal!

Here is a site (http://www.lasc.us/CastBulletNotes.htm)with some alloy compositions.

Since each piece is different, smelting it together and then having it analyzed is what I would do, and in fact is what I did in a similar situation. Once you know the new alloy composition, you can use that to accurately make whatever you want.

The trace amounts of copper won't cause you any problems.

John

[HeavyMetal]

I think you've got a good idea. If the pieces you had "scanned" are representative of the whole bucket It looks like the end result will be very close to a real Linotype alloy.

Mix it well, flux the snot out of it, and then get a 1 lb ingot or two scanned. Make sure you write down the composition of the new mix!

Once you have a known alloy you can increase or decrease hardness on the brinnell scale by adding WW or water dropping the cast boolits as needed.

Looking forward to seeing what you actually wind up with.

[454PB]

Are the "pieces" in the form of letters?

The analysis sounds about right for monotype.

[Ugly Dwarf]

Are the "pieces" in the form of letters?

The analysis sounds about right for monotype.

Yup, each piece has a single letter (or number) on the face of it (pehaps the reason for being called "Mono"). Some are solid pieces, others are more of a 'frame' with a hollow middle.

The thing that threw me was that I was expecting it to be a relatively consistant mixture, based on the style of "type" (as in, Lino would be one composition, mono would be another, foundry yet another, but all of each kind would be more or less the same).

Example "2" threw me off, since that was the composition I would expect for lino, but it was a single letter, not a "line".

I will blend it all together the next time I have a smelting day. I figure I can melt it down in about four batches (given the capacity of my pot), and then I can mix equal portions of each batch and cast new ingots.... wow, that's starting to sound like work.

Any recommendations on a good temp for alloying these? One of my searches seemed to indicate hotter (750+) is better for monotype.

As for fluxing, I was planning to use some Pat Marlins CFF. I also have parafin on hand... is that better for this application or is it good to use the two in combination?

[Harry O]

From your description, you have monotype. I have a couple of buckets myself. It works great at sweetening pure lead.

There are four primary recipies for monotype. The two most common are close together and are used about 75% of the time. The other two are different, but are less likely. One is harder (more antimony) and one is softer (less antimony.

This is what I use when calculating hardness (it is an average of the two most common types).

Monotype = 73.0% Pb; 17.5% Sb; 9.5% Sn; Bhn = 28

Monotype is not a eutectic metal like linotype is, so it can have more variation in its content.

[cohutt]

I have some I haven't messed with yet.

I seem to recall that it gurgles up all kinds of crud in a smelt- post results if you remember.

[454PB]

If it acts like the monotype I have, it will "froth" heavily when first melted. Flux it thoroughly until you see the froth break down and dissolve into the melt. Don't skim anything off until this happens!

Theoretically, the more tin in an alloy, the lower the melting point. Pure lead melts at 621 degrees, so monotype should melt at around 450+ degrees, but I have never used my casting thermometer to check.

[cohutt]

Thanks for the info 454, the "froth" is what i had heard others talk about

[Ugly Dwarf]

Talked with the Misses today and blocked out some ME time tomorrow morning. With any luck I'll have some ingots to show for my work. I'll try to bring my camera out there and take some pictures.

I've got a covered patio that I've smelted on in the past, so I should be fine even if it rains tomorrow.... we can use the water, but I'm hoping the weatherman is wrong by a few hours and the showers wait for the afternoon.

I also plan to try casting my first bullets tomorrow with some WW I turned into muffins last Fall. Again, I'll try to take some pix of my results.

I'll let you all know how it turns out.

Dwarf