Unusual Etch on a Moro Blade

[Spunjer]

Originally Posted by DaveS

Spiral: I've had this happen before also after using vinegar to neutralize the
Phosphoric acid that i usually use to etch blades. It seems strange
to me that one acid can be used to neutralize another, but i guess
for some reason it works. Try also heating blades on both sides with
a torch (very carefully). Then apply acid. It seems to emphasize
the high-carbon areas of a blade with some really good results. If
the blade turns out too dark simply repolish, and try again....Dave

i would normally use a heat gun (use to strip paint) to warm the blade, not hot to touch, before applying my first layer of warm vinegar. you're right, in that it does emphasize certain areas of the blade when etching. never tried phosphoric acid, dave. pretty much stayed with vinegar.

mross: yes it does. but what i don't understand is why is the opposite side has a different pattern? was the core sandwiched together?

[mross]

Originally Posted by Spunjer

mross: yes it does. but what i don't understand is why is the opposite side has a different pattern? was the core sandwiched together?

Sounds reasonable, that would be my guess. Since I'm not sure, if it's ok I can post the photos on one of my bladesmith site's and see what the guys who make this type of stuff think is going on. Or you could just cut it in half and have a look.

[Spunjer]

Originally Posted by mross

Sounds reasonable, that would be my guess. Since I'm not sure, if it's ok I can post the photos on one of my bladesmith site's and see what the guys who make this type of stuff think is going on. Or you could just cut it in half and have a look.

mross, have at it! if you want, i can email you the actual pics. i think i have a good idea on the make up of the blade, but it would be nice to hear from the bladesmith's point of view. the setup seems to be a popular theme among moro weapons (sandwich lamination).

[G. McCormack]

my impression is that silica type impurities took that golden hue from the etch, revealing a normal folded and welded structure. Was your etchant brand new and clean, or had it been used before?

[Spunjer]

Originally Posted by G. McCormack

Was your etchant brand new and clean, or had it been used before?

it's brand new and clean.. always been a habit of mine to never reuse the same etchant on a different blade. besides, vinegar's pretty cheap as a matter of fact, the kris that i etched right after this came out "normal" (shown both sides). again, notice the different lamination structure variation on each side.. (sorry about the lighting.. took it under less optimal condition. the brownish tint was due to the artificial overhead light. actually it came out similar to the barungs above..)

[mross]

Originally Posted by Spunjer

mross, have at it! if you want, i can email you the actual pics. i think i have a good idea on the make up of the blade, but it would be nice to hear from the bladesmith's point of view. the setup seems to be a popular theme among moro weapons (sandwich lamination).

The smith's are in agreement with you on the construction.

Here is the link.

http://forums.dfoggknives.com/index.php?showtopic=23350

[Spunjer]

thanks for the update, mross!
somehow i'm beginning to think the pandays of old had these pre-made blank billets lying around so when it's time to make a kris, he picks up a couple to sandwich a core.

[delor]

I agree with mross. The "random" pattern is the proof of a laminated construction.
If there is no sign of lamination between the edge and the first brown line, this could possibly be a sandwich construction with central single steel (not sure, according to your two last photos which seem to show uniform lamination on the whole blade).
A good reason for sandwich construction is that a combination of non "quench-able" materials (ie : low carbon steel and nickel) was often used for lamination, in order to get good etching contrast (steel goes dark grey and nickel remains bright). If the laminated material canot be correctly hardened, this leads to sandwich construction which allows to have some good steel at the edges. Also good steel was much more expensive in the old days than common iron, so the less steel used the better it was for economical issues.
I cannot say what are the materials used for the construction of your blade. Might be iron + steel...

[Spunjer]

thank you, delor, for a thorough explanation in the lamination process! would you say that the core is a solid piece, or would it resemble a tuning for (with the edges as tines)? ,

(not sure, according to your two last photos which seem to show uniform lamination on the whole blade)

.

the last two photos are actually from a different kris i etched on the same day. i added the additional photos as a comparison to the original kris that was posted