Unusual Etch on a Moro Blade

[Spunjer]

@spiral: thanks! I do have this habit of running a hot water test on these blades to see if they're laminated. When I did it initially, none of those patterns came out.
On your multi, did pattern stayed, or did it eventually fade? Yes, you're right: healthy dose of oil was applied right after...
@dave: It's brass, I'm pretty sure. It's just that it is the lighter shade type, not to mention I went against the grain and decided to clean it up. Of note is the weight of this beast: it's heavy, comparable in heft with kampilans.

[spiral]

Originally Posted by Spunjer

On your multi, did pattern stayed, or did it eventually fade? Yes, you're right: healthy dose of oil was applied right after...
.

It stays, but much cleaning fades it, I guess longer oxidisation leaves a more permant mark, a questian of getting the right balance I think?

Spiral

[Sajen]

Originally Posted by spiral

It stays, but much cleaning fades it, I guess longer oxidisation leaves a more permant mark, a questian of getting the right balance I think?

Spiral

Yes, agree, have similar operating experiences.

Regards,

Detlef

[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

[mross]

A weird color but looks like fold patterns to me.

[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).

[spiral]

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 think vinigar may dilute a stronger concentration of another acid Stan, but to neutralise it, will need an alkali, I think? vinigar still needs washing of or neutralising or will promote further oxidisation.

Lots of water washing & oill often suffices though.

Spiral