Brass \'n\' Bronze tricks o\' the trade

[Hibernicus]

I don't think I shared this "trick" with anyone... I just kind of assumed...<br>
<br>
When working with thin brass or bronze: to temper it (harden) heat it up to a nice orange then let it cool slowly.... the trick is to let it cool very slowly.. if you let it cool in the air or on top of a metal surface it will cool too fast and not become as tempered as it should be.<br>
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Do as we do... place it in a container of sand, bury the piece.. this will allow it to cool slower.<br>
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Another trick to making fittings that are as thin as .025 is to start with .030 and hammer it with a flat head hammer.<br>
This does several things:<br>
1) it thins it<br>
2) it puts tool marks on the surface<br>
3) it makes the metal a bit denser and when you temper the piece it becomes a bit stronger.<br>
<br>
Hibernicus <p></p><i></i>

[scythius]

<br>
Oh, yeah - if you can heat the sand up, it works even better...<br>
<br>
<p>Scythius<br>
LEG IX HSPA - COH III EXPG - CEN I HIB<br>
<br>
- FIDELITAS - - VIRTUS - - MAGNANIMITAS - </p><i></i>

[Anonymous]

Brilliant!!!!<br>
<br>
more of this please!!!! we should get a new topic on here called the Smithing corner!!! with all kinds of metalworking tips and tricks!<br>
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BTW.. any idea of the correct thickness for messing(bronze) greek-style shoulderplates for my musculata in the making?<br>
<br>
re doing a 100 year old theater musculata which looks rather good..... not finished yet though....<br>
<br>
greetsss!<br>
<br>
<p><span style="color:yellow;font-family:times new roman;font-size:medium;">M.VIB.M.<br>
V COH II<br>
LEGIO X GEMINA<br>
EX GER INF</span></p><i></i>

[Anonymous]

Ave, Marcus! To my knowledge, Greek-style musculatae did not use shoulder plates at all, but rather a hinge at the shoulders that affixed the back plate to the chest plate. Shoulder plates (assuming you mean the large single plate that runs front-to-rear over each shoulder, and is fastened down using a post-and-eye type closure system) appear to have been a wholly Roman addition to the design.<br>
<br>
(not to be confused with "Holy Roman" additions)<br>
<br>
Vale,<br>
Darius<br>
<p></p><i></i>

[Anonymous]

Thanx mate!<br>
<br>
i will try to post an image of the "thing" on here soon....<br>
<br>
it originally had shoulderplates.... but what i meant was shoulder plates, looking like Greek linothorax shoulder straps.... the shape like you see on some chain mail shirts...<br>
<br>
only smaller and more Roman.....<br>
<br>
greetz<br>
<br>
<p><span style="color:yellow;font-family:times new roman;font-size:medium;">M.VIB.M.<br>
V COH II<br>
LEGIO X GEMINA<br>
EX GER INF</span></p><i></i>

[richsc]

I ran across this thread: anyone try the trick of slowing cooling brass in heated sand? How the heckdo you heat a bucket of sand?

[Magnus]

Richard, you can heat the sand in the oven if you have a metal bucket.

I also think you can "normalize" (temper) the brass by heating it to around 300 - 350 degrees for about an hour. Repeat this procedure 3 times or so and the molecules in the brass should all be aligned again. This method works if you don't have access to a hot enough torch, and plan on cooking a roast in the oven!

[Matthew Amt]

Um, there seems to be some confusion of terms, here, thought it's quite possible that they are simply not consistently used even among experts! "Hardening" is straightforward. I think we all agree that "annealing" is softening the metal by means of heating--heating and quenching for copper alloys, but heating and very slow cooling for iron and steel. Heating and quenching iron or steel hardens it, but will anneal copper alloys. Both types of metal are also hardened by hammering or working. Iron and steel can of course be worked hot, which prevents work-hardening or stressing, but for copper alloys it is generally safer only to hammer them cold, and re-anneal as necessary.

Now, the confusion is that I learned that "tempering" can only be done AFTER hardening! A piece of steel is worked to shape, then hardened by heating red-hot and quenching. This makes the metal very hard but also brittle--it can break or shatter if struck. So it is *tempered* by careful reheating, to a point where color changes are visible: straw color for the hardest, blue for the next, etc. I watched a blacksmith do this with a chisel he was making, and it was fascinating! The sound of the dead-hard metal was a dull thunk, but after tempering it rang. He said that trying to temper unhardened steel was like trying to slam a door open, an expression which has stuck in my mind. But like I said, there may not be agreement on the precise terms. I'm not sure about the differences between iron and steel regarding hardening and tempering, but I do not think that copper alloys can be tempered, as I understand the process. Just hardened or softened.

Another one is "normalize", which I took to be about the same as annealing--it is returning work-hardened and stressed-out metal to its normal state by heating to soften it (followed by slow cooling for iron or quenching for copper alloys).

I do know that bronze age weapons generally had their edges hardened by hammering. There doesn't seem to have been any need to use heat-hardening, though annealing was certainly done.

Valete,

Matthew

[Magnus]

^ ^ What he said! 8)

[arklore70]

Speaking of Brass and Bronze secrets.

Does anyone know if Deepeeka brass Helmets come with a lacquer finish? I would think that if they do it would need to be removed.

Most modern military brass, instruments, and what not seem to come with a lacquer coating, thus why I ask.

Normally it has to be removed in order to get a real shine out of it.

Thoughts?

Cheers!!

Mike

Oh, Never Dull works great and is a lot less messy than Brasso.

[Peroni]

As far as I am aware the Deepeeka brass helmets are NOT laquer finished.

Regards,

[Magnus]

Yep..no lacquering. Just tarnishable brass.

[Matt Lukes]

Matt (Amt)'s quite right about the definition of tempering- so what hibernicus was so generously sharing was a way to re-harden brass after it's been annealed. Personally I arrange work such that I only anneal it up until the last series of hammer strikes will make it more-or-less the way I want it so it's that hammering that leaves it hard. Although it doesn't seem to entirely make sense in light of the known method of hardening copper alloy by allow allowing slow cooling, I've found that when a piece heats up to the point it's hard to hold, for example during aggressive polishing, not quenching it but allowing it to air-cool, seems to empart some harness as well.

Matt

[Magnus]

Hey Matt (Lukes), do you know if we canucks can get polishing compounds like Flitz or never dull in Canada? All I've found so far is autosol.

[Matt Lukes]

I don't know Matt- the polishing compounds I get are just 1lb blocks made by a company called 'Tricyclo' in the various colors (abrasiveness)- black, green, rouge, etc. - or are you talking about stuff that's more like Brasso?