Hi!

I've been wondering about this.
I've tring different acid for revalation (muriatic, " very " diluted ferric, vinegar). combined with different polish.
In an Oakshott book (not sure wich one...) there was something about pattern seen with the sunlight playing on the blade ( the snake crawling on the blade I think)
Was the pattern welding on ancient blades as bold as it is seen today? Would it have been closer to the asian polishing techniques, chinese for exemple?


Antoine

There was some discussion of this last year -
http://www.myArmoury.com/talk/viewtopic.php?t=5464
My guess is that the blades were not finished to look as bold as they do today, but I've seen a couple artifacts from the Viking period that look like the damascus may have originally had some topography - so not as subtle a finish as the asian style either.
Here is an oxidized surface of a Viking blade which may mimic the original surface texture -
http://bjorn.foxtail.nu/museum/pattern.jpg
(from Bjorn's sword site - http://bjorn.foxtail.nu/swords.htm )
Oxidation always increases the depth of damascus (if it does not obscure it completely), so there must have been less topography originally.

In our workshop we mostly use vinegar essence, since it is not likely that strong acids like those we have today were used in the earlier periods of the middle ages. The pattern is nicely revealed, but you get no topography whatsoever. Without a very careful polish afterwards, they appear very grey (see attachment). I doubt, however, that the swords were etched in the earliest periods (La Tène for example), as the use of pattern-welded steel merely represented a technical necessity at that time (apart from exeptions) .
[ Linked Image ]

Might be worth a try to use lemon juice on a test piece: I've used that to age a few blades ( Cheap ones ) leaves a dark greyish finish that can be lightened with fine steel wool. Worked well creating phoney Damascus using soaked toilet paper that had a pattern on it and repeating a few times to randomize the pattern.

In your case with real Damascus the goal would be to reveal an existing pattern and not etching a phoney one.

Maybe filling a tall container with lemon juice or mild citric acid might work. ( Or vinegar ? I think some people have used mustard also to stain a blade ? Oh, considering how well cutting tomatoes can stain a carbon steel kitchen knife maybe tomato juice could also be tried ? Or, go crazy and mix-up all of the above. :eek: )

Mustards works almost as good as vinegar, or it should since there is vinegar in the mustard. ;)
I always use a plastic container filled with the essence. How long it takes the pattern to reveal itself depends on the steel which was used for the blade (and the concentration of the vinegar of course).

Depending on the PH of the local water, if acidic it can bring out patterns a good amount during polishing. Here in Indiana with the more course levels you can watch a fresh polished area start showing signs of oxidation (rust) in under a minute, and most of the way covered in five or ten. Some polishers will even add baking soda to the water to help avoid it. As you go higher in the level of polish you can start to see the etching effect the water has on the steel. Depending on the level of contrast between the irons and steels used, it might not really take that much work to make patterns clearly visible. Acidic liquids like beer and vinegar could have easily been used. Even back in the La Tene period we have blades that were not of piled construction, that appear to be etched to give blades various patterns. Some of these even include designs that look to mimic blades made with a piled construction.

Today lemon juice, vinegars, and ferric Chloride seem to be about the most popular acids used today for blades, although other things are certainly used. Lemon juice seems to work about the best if you are wanting to bring out something like a hamon. Vinegars seem to be a bit better if you want to make folding a little more bold. Then the ferric if you just want to get the strong contrast between steels, or get any kind of deep depth to the etch. Of course the strength of all of them can be adjusted with water. Many things play rolls in this, so results may vary.

Shane