Obsidian Shards

[Laredian]

So I had two thick pieces of steel lying around that were too small for my usual designs, but too big to not use them. So I made some small edc knives, and since it was rather thick stock I tried a rock pattern steel handle, which I wanted to try for some time anyway.

I wanted to go for a look where, once I blacken them, the knives somewhat look like they have been carved out of a piece of obsidian:

(sorry for the crappy pics)

Grinding all those facettes at different angles was fun. I sort of rough shaped them with a 36 grit and then tried to trace the grooves and facettes I had ground with a 240grit belt. I obviously couldn't do this perfectly so I ended up putting more facettes into the handle, which ended up looking quite alright.
While it was fun, I am not looking forward on chasing the different grooves and facettes again on my grinder after heat treating with a higher grit....and I am so not going to hand sand those.
So now I am looking for advice as to what is the most efficient and practical way to finish them after heat treatment. Is sand blasting the way to go? The goal is to blacken them with a ferric chloride patina....and maybe stonewash them, I am not sure.

 

[Stacy E. Apelt - Bladesmith]

I call that a knapped look handle. I do blades with the knapping to simulate stone knives. After HT hit them on the buffer with black rouge ( emory) and then a finer polish with red rouge. Clean up well and patina as you wish. Parkerizing works very well on this surface.

 

[Laredian]

I call that a knapped look handle. I do blades with the knapping to simulate stone knives. After HT hit them on the buffer with black rouge ( emory) and then a finer polish with red rouge. Clean up well and patina as you wish. Parkerizing works very well on this surface.

Thank you for the advice stacy.
I admit that I have very little experience with buffing and I do realize that it is an entire skillset on its own that probably takes some time to master. Having said that, does buffing not wash out the nice, crisp transitions between the grooves and facettes on the handle?

 

[Stacy E. Apelt - Bladesmith]

To a degree, yes.
It can be minimized by using a hard wheel and repeating the "cuts" made with the contact wheel. That is - instead of buffing up and down the handle as a whole, buff each facet individually. A hard felt wheel or hard stitched treated muslin buff would be good here. I would suggest a 4" wheel.

If you are OK with a satin look, then you could try sandblasting as you suggested.

Too late for this knife, but placing the facets after HT will eliminate the issue. Just rough it out pre-HT and then make crisp facets post-HT.

 

[Laredian]

Wanted to say thank you for the advice I had gotten here. I recently finished them:

I really like how they turned out and I learned a lot about stonewashing. Kinda tricky to get it right. I really had to experiment with the medium...how much to use, in what combination, how long to stonewash and in what motion etc.
I think the effort paid off though.

Edit: Pictures stopped working for some reason...

 

[weo]

Those look great. Care to share you experience, and what ended up working for future reference?

 

[Drew Riley]

Those came out really nice. I too would like to know how you ended up doing it.

 

[Laredian]

Those look great. Care to share you experience, and what ended up working for future reference?

Those came out really nice. I too would like to know how you ended up doing it.

Thanks
Right, so the first thing was to get the scale off the handle after heat treatment. You can't just leave it and go into the etch because it won't etch evenly. So I etched them in vinegar first for some time to get rid of most of the scale and then sanded the handle to a rough 320 grit and the blade to a semi nice 500 grit finish.

Then I etched them in ferric chloride. Make sure your workpiece is properly degreased because and even etch is key (though the stonewash can cover some uneven spots in the etch, but I wouldn't count on it to look good). You can etch multiple times depending on how dark you want your blade.

Then you need a proper medium for the stonewash. I used a combination of ceramic cylinders and triangles. Ordinary stones or gravel don't work for me personally.
Then get a proper container for your medium. For such a small blade a rectangular plastic milk jug with a lid works fine because of the shape, your blade just needs to fit in and it should have a lid. The shape of the container is important because you want to insure proper circulation of the medium, at least if you choose to rotate it. If you use a round bottle, the medium wont properly circulate during rotation.

Then you either shake or rotate your container, either motion yields differend results in the finish. You can even do this by hand like me, or you buy a vibratory tumbler or simply build a tumbler yourself. (doing it by hand and getting good, even results only really works for small blades though in my opinion)
The rpm and time the blade sits in the container are important too. I suggest you start with 30sec to a minute intervalls and check the blade regularly, because if you don't stonewash enough it looks sloppy and if you do it too much, it just looks scratched and ugly....in my opinion at least.
One last thing: be aware that the finish will darken when you oil the blade up after the stonewash.

Hope that helps

 

[Lapedog]

So I had two thick pieces of steel lying around that were too small for my usual designs, but too big to not use them. So I made some small edc knives, and since it was rather thick stock I tried a rock pattern steel handle, which I wanted to try for some time anyway.

I wanted to go for a look where, once I blacken them, the knives somewhat look like they have been carved out of a piece of obsidian:

(sorry for the crappy pics)

Grinding all those facettes at different angles was fun. I sort of rough shaped them with a 36 grit and then tried to trace the grooves and facettes I had ground with a 240grit belt. I obviously couldn't do this perfectly so I ended up putting more facettes into the handle, which ended up looking quite alright.
While it was fun, I am not looking forward on chasing the different grooves and facettes again on my grinder after heat treating with a higher grit....and I am so not going to hand sand those.
So now I am looking for advice as to what is the most efficient and practical way to finish them after heat treatment. Is sand blasting the way to go? The goal is to blacken them with a ferric chloride patina....and maybe stonewash them, I am not sure.

It’s probably too much of a pain to do on these but the best effect I have ever seen on steel to create an obsidian like finish is actually polished DLC.

I have seen some outstanding knives with this finish and it creates a very polished hematite kind of look.

Like this and it reflects like a mirror.

 

[weo]

Hope that helps

Yes, thanks. I thought it was going to be much more complicated than that.

... the best effect I have ever seen on steel to create an obsidian like finish is actually polished DLC.

Did a quick google search as I've never heard of this and I'm curious if this is something one can do in their shop or do you have to send the blade to a place that does this (which is what it looks like to me so far....)?

 

[Lapedog]

Yes, thanks. I thought it was going to be much more complicated than that.



Did a quick google search as I've never heard of this and I'm curious if this is something one can do in their shop or do you have to send the blade to a place that does this (which is what it looks like to me so far....)?

I’m not sure how you would do it. I think you would have to send the knives to get dlc coated and then polish it yourself.

 

[weo]

Gotcha, thanks Lapedog !

 

[Laredian]

It’s probably too much of a pain to do on these but the best effect I have ever seen on steel to create an obsidian like finish is actually polished DLC.

I have seen some outstanding knives with this finish and it creates a very polished hematite kind of look.

Like this and it reflects like a mirror.

Yes, thanks. I thought it was going to be much more complicated than that.



Did a quick google search as I've never heard of this and I'm curious if this is something one can do in their shop or do you have to send the blade to a place that does this (which is what it looks like to me so far....)?

The principle of the stonewash is not complicated, the devil lies within the details, as with most things in knifemaking. Regarding the Rockstead knife: u are right that finish looks more like obsidian.
I am also curious how they do it. Because if they polish it after it was coated, I don't understand how they get that surface without a single scratch on it. Or they polish up the blade to a mirror finish before dlc coating and then just give it a very light, thin coat....
But I dare say that a stonewashed or acidwashed finish will look better when the knife is actually used, because any scratch on the rockstead blade will be immediately noticable.

 

[Laredian]

I had to fix the pictures again because I had some problems with the image hosting site that I use. While I am at it I was looking for advice. I am not sure where to put my makers mark on these. Usually I put it one the spine of the knife like this:

(one of the first professional pictures I had taken btw, because I am really bad at it)

However I can't really do that on these because one they are etched and stonewashed, so there is not a blank spot on the spine. And second, because of the rock pattern handle there is no flat surface on the spine.
I could try to etch it on the blade, but I am not sure whether it would look good. Also I don't know what the result would look like if you try to etch your mark on a surface that has already been etched.
I stamped my mark on the leather sheaths I made for these (pictures coming), so they are kinda marked, but I'd like to have it somewhere on the knife aswell.

I'd be thankful for any advice.

Edit: pics with sheaths added