Enamel and brass inlay on pugio sheaths

[Marcus Mummius]

Salve,

I have a question about 1st century AD pugio sheats with both enamel and brass inlay. How can this combination be made?

Was the enamel done first or the brass inlay? If the brass is inlaid first, doesn't the zinc(Zn) in the brass evaporate while firing the enamel?

If the enamel is done first, doesn't it crack or get damaged while doing the brass inlay?

I hope someone can help.

Vale,

[Tarbicus]

Jef, you could try doing the brass first, and then use cold enamel which was discussed a week or two ago.

http://www.romanarmy.com/rat/viewtopic. ... 015#123015

If you're asking how it was done 2000 years ago, I haven't got a clue.

[Marcus Mummius]

Thanks Jim, I know about the cold enamel. :wink: I'd really like to try real enamel. A modern substitue like the cold enamel will be my last resort.

Vale,

[Celer]

Salve Marcus,

Firstly, you would do all the engraving for the wire and enamel.

You would have to do the inlay first. When you hammer it into the grooves, there should ideally be some wire left spreading out on the surface. You simply file this down flat with the surface of the scabbard, and then apply the enamel. If you did it the other way around, you would risk cracking the enamel (it is after all only glass) when you hammered in the brass/silver wire.

Originally, the enameling was usually applied as a powder and baked in a kiln to melt it. When it cooled and solidified it would be coloured glass. There are plenty of web sites giving advice on hot-enameling, and you can get either electric or gas-heated kilns. If enameling on silver or copper-alloy though, be careful, as you can easily melt the metal base (Something my father did on his first project).

Hope this helps.

Vale,

Celer.

[Marcus Mummius]

Hi Celer,

Thanks for your answer. I'm familiar with the technique, that's not the problem problem. The problem is the copper alloy inlay. Zinc boils at 907°C.

For the enamel to melt it has to be heated between 750 and 850°C... This might be very tricky... There is not a lot of room for error between 850 and 907°C... :? I wonder how the Romans could control the temperature in such detail...

[Peroni]

I wonder how the Romans could control the temperature in such detail...

Probably by years of experience, good control over hand bellows, and an eye for the correct flame colour.

[Marcus Mummius]

I wonder how the Romans could control the temperature in such detail...

Probably by years of experience, good control over hand bellows, and an eye for the correct flame colour.

I agree but at such a high temperature a 50 degrees difference is very difficult to spot...

[Gaius Julius Caesar]

and not wandering off to fix a snack and watch TV. or surf the web.... :lol:

[LUCIUS ALFENUS AVITIANUS]

Romans did the enamel in kilns, like in our days. At 950 º the problem with the brass could be it melts, but without a fundent (borax) or so, its dificult it happens. In the other hand, if you only need 850º you are under the fussion point (950º), so no problem.

Probably the enamel composition of our enamels and the roman ones was not the same, so the room of error was not the same as today.

And a good artisan today could knows very exactly what its the temperature of a metal simply looking the colour. Until 860º you have a dark red (brick) colour. When you get the 850/860 the colour beginns to change to a cherry red, not so dark and more shiny. The roman artisan, who are looking constantly the piece in the kiln, then knows that if the temperature increases he lost the piece, and can do some actions like get out the piece or put less air into the kiln. (the kiln for make such things have a forced aireation)

To make that yourself...Uf, its dificult. Now we have some aid with the propan torchs. You can use it to make enameling instead a kiln. But the heating must be not direct, so you can heat with the torch the back of the piece. I can't say how is the method to avoid a overcooking of the piece, probably it's a matter or looking the colours of the hot enamel (i think a orange colour is fine. Think the hot colour is the same for all the enamels with independence of the final colour) and avoiding the formation of bubbles (when the enamel boils, just before "burning")

The trick is made a lot of experimentation with fake pieces, and then go for the final thing.

Good luck! Think that probably the efort deserves your work. And remember to put some pictures...

[LUCIUS ALFENUS AVITIANUS]

Better, go to that site. Here, they explains how can make yourself that work. I hope it helps you.

http://pinzart.zoovy.com/category/libra ... _enameling