I have a knife that i made a while back that I made out of SS. Not sure what grade, but I have a guess that it's 318. I have soaked it in some partially muriatic acid, and it didn't take the scale off of it. I know a grinder will take the scale off, but I don't want to use one b/c of the twisting that I have in it. What can I put this in to remove the scale? :confused: Any and all info will be greatly appreciated.

Thank You All,
-Tony

If its 300 series stainless, then the steel is not going to harden. If its for decorative purposes fine, but it will never be useful as a using blade. Getting the scale off is going to be a matter of elbow grease. I do not know of any solution that will take the scale off 300 series stainless. Your best bet is a wire wheel, and a lot of elbow grease.

I am not a bladesmith but have forged a lot of stainless. I have always used a progresion of sandpaper, I always wish to contrast the stainless shine with the fresh from the fire look. Passivating would be one answer. Citric acid for longer period? scotch brite the highlights?
beadblast and sandpaper. Several gallons of elbow grease.

Acid is used to remove scale by forming hydrogen bubbles under the scale and popping it off. If the steel, such as an austenitic grade is non-reactive in acid, no hydrogen will form and the scale remains in place. Now where is that can of elbow grease?.........

What of electro polishing? I rigged a small unit in my garage to clean up some 316 SS parts I had made. I used some metal prep (main ingredient phosphoric acid) for the solution. This particular stuff also had detergent in it and it foamed like the washing machine in an old sitcom. just call me Lucy. There are some write ups of the base procedure on the web.

What I describe won't make it really shiny but it does remove crud where you won't need as much elbow grease to get real shiny.

The use of acid in a galvanic cell, such as in a sufuric or hydrochloric acid bath, generates hydrogen as a result of the reduction/oxidation reaction taking place and it also generates a small current. This is, in effect, a battery. If you apply the current, you are forcing the current to flow to run the redox reaction, and this liberates the hydrogen that breaks up the scale. Same action taking place, current flow is reversed.

try wire brushing it or use a finise but works her designed for wood finishing for the end of a drill it will take a long time but it works nice

knifesmith13
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