Electrolysis & Stainless a Bad Mix?

T

The Mighty Ginsu

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Aug 11, 2016
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I am still working on my first knife, using 440C steel. I decided to save money by getting steel that still had the mill scale on it. Now I'm having fun dealing with the scale. I would kill to have a surface grinder right now.

Soaking the blade in vinegar for 18 hours didn't get me anywhere, so I decided to try electrolysis. It sort of worked, but the steel still has a lot of pits in it, and the electrolysis water is green, which makes me wonder if it's full of chromium.

Is it a bad idea to use electrolysis on stainless? I just assumed it would leave the metal alone while eating the oxides.

I have another unrelated question: is it realistic to hope to make enough money selling knives to pay for the hobby? I don't mean house payments and grocery bills; just tools, steel, and so on.
 
Knife making is a labor of love. You can get into it inexpensively using only files and other simple tools but you will start to want the bigger toys that cost money. For now I would not look to trying to create knives for sale. Instead, focus on making one knife at a time and learning from mistakes. Further down the road, yes it is possible for it to pay for itself but you need to have the quality and craftsmanship to do that. Do a bunch of research and more research to get a good foundation of knowledge to build on. As for the scale, as you file down the knife bevels etc. you should be able to get rid of it. Though for my first knife I would ditch the 440 and go with a high carbon steel (more forgiving).
 
Hi there Mighty Ginsu.
Did you read the stickies at the top of this page? There is lots of information up there to help.
I would suggest this for your "reaching out"or "research and development" don't push it too hard but ask here first, maybe.If the vinegar didn't change the surface of the steel then there wasn't any scale to be removed and it was ready for your shaping.
Knife making can get you the necessary tools to work with but the learning curve to do the work for many of us can be very steep and a long slow journey is needed.
Frank
 
Thanks for the help.

I am now thinking the smart move would be to dissolve the scale, which I can do with acid, and then superglue the blade to a piece of metal big enough to mount in a mill vise. Then I should be able to skim off enough metal to get rid of the pits, and because the hard scale would be dissolved, I shouldn't have to worry about the damaging an end mill.

I was thinking about gluing it to a flat piece of metal and turning it on the lathe, but if it came loose things would get interesting.

I have been making ample use of the stickies, and I will keep referring to them.
 
Wouldn't it be easier to just buy another piece of steel?
 
The google query "pickling agent for stainless steel" will get you going in the right direction for question #1. Example result: "Our pickling solutions for stainless steel are mixtures of nitric acid and hydrofluoric acid."
 
When purchased new, does 440C stainless (or any other stainless) really have all "that" much scale? I don't remember any heavy scale on any SS I've purchased and I'm not talking about ground SS, just run of the mill type SS. Now, after HT'ing if it's not in foil there sure will be a LOTS of scale, but I'm talking steel from supplier.
 
Ken H> said:
When purchased new, does 440C stainless (or any other stainless) really have all "that" much scale? I don't remember any heavy scale on any SS I've purchased and I'm not talking about ground SS, just run of the mill type SS. Now, after HT'ing if it's not in foil there sure will be a LOTS of scale, but I'm talking steel from supplier.
Click to expand...

If it appeared clean but not surface-ground, it was pickled.

EDIT: or it was cleaned via shot-blasting or similar means
 
Someone is trying to tell me stainless steel never has mill scale. Is that true? This steel was dark grey when it arrived, and whatever is on the outer surface doesn't shine up when you use abrasives. It also left a layer of green stuff (along with some rust) in the solution when I tried electrolysis, which suggests to me that some kind of chromium oxide came off of it.
 
Stainless can have quite a lot of scale at times... I never see any on AEB-L but have seen really scaled up pieces of CPM-154.

Try some slightly used rough grit ceramic belts and grind that stuff off... you should be done in a few minutes. No fun but not bad at all. I like to leave the scale on if it looks cool, just be sure to grind it away anywhere the knife will have an edge.
 
Thanks.

I considered using a belt to get the crud off the blade I'm making, but I was concerned that it would round off the edges so there would be a gap between the handle scales and the metal. Maybe I should make blades oversized, cut the scale off, and then grind off the rounded parts?

I guess I'm stuck with a diamond stone for the blade I'm working on now, but I'll try to do something more intelligent next time.
 
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