[Dustin Faulkner]

Hello:

I was wondering if anyone knows how decorative patterns were etched onto weapons during medieval times. I admire the work I've seen on many polearms - especially halberds and glaives.

I am guessing (please correct me if I am wrong) candle wax was poured onto a blade's face. The desired pattern was cut into the wax after the wax cooled & hardened. Then the exposed metal was etched with an acidic liquid like urine. For how long, I do not know.

Metal covered by the wax was not etched.

Anyway ... this is only a guess. I defer to those of you who might know better or have actually etched replica pieces. I was simply trying to figure out how they would have done it in previous centuries without modern etching chemicals and techniques. I assume urine and candle wax were very common back then.

Of course, I have not yet tried my idea myself! It's too cold right now!

[Leo Todeschini]

Etching is done by applying a mask and it etching this is called a 'ground' and all areas of the metal you want to preserve are covered by this ground. This is a basically any material that allows you to easily remove some to expose the metal and so make patterns, pictures or whatever. Beeswax does work for this.

However if you want to get a good level of detail in you need a ground that adheres well to the surface but will allow itself to be removed in very fine amounts and beeswax does not do this, so fine for large crude etchings but bad for fine work. Hard ground as a fine etching mask is called is made from pitch, beeswax and rosin (usually) and is applied to a hot item to melt into a film and dabbed off to create a very thin and hopefully even film. When cool this can be handled without removing the mask and scratched to cut in a pattern.

There are of course other ways but this is the principle and traditional type of mask.

The etching compound used most frequently nowadays is ferric choloride which is fact a salt and so is realtively safe and it basically rapidly rusts out the decoration. Nitric acid can also be used and was, but is far more dangerous and aggressive and for lighter etches in hotter climes citiric acid from lemons and limes can be used. I am sure there are and were others as well.

Urine, although as you suggest was common, is in fact not acidic and although is salty and so would cause some corrosion above the plain oxidisation created if it were water, would not be aggressive enough to etch significantly.

You do mention temperature and this is important as all the reactions that cause the metal to be etched work faster at higher temperatures, so a 1 hour etch at 40 degress C is about the same as 8 hours at 15 for example (about)

Tod

[Matthew Fedele]

They had a good variety of acids and the knowledge to create them including hydrochloric (muriatic) and acetic (vinegar.)

I recently used undiluted silver etch (nitric mostly) and it was a bit too aggressive. Here's a photo.

Cheers,
Matt

[img][/img]

[T. Hamilton]

[Sean Flynt]

For the later German style of etching (16th c.), in which the design is in relief, you use the resist like you'd use paint, applying the design with a fine brush and making little dots on the background area. The acid leaves all of those areas raised. This is what you see on the fine 16th c. German arms and armour.

[Matthew Fedele]