Removing some relatively fresh patina?

[Thpp9]

Hello,

Some weeks ago I grabbed a Takada gyuto and I've used it some fair amount. It has developed some patina that has started becoming brownish. I would like to remove it without scratching the knife. I would use some metal polishing but I find that the knife loses the contrast between hagane and jigane, at least on wide bevel knives. I considered baking soda slurry but I don't know how abrasive it is.

Finally, I've got some suita natural powder laying around. The patina is kinda fresh so I think it would be able to remove it. Would it be a good solution for polishing the knife without altering the original finish?

 

[M1k3]

Baking soda slurry, lemon juice or vinegar would be good to use instead of water, will be the least abrasive. Flitz or autosol would be some other options, although mildly abrasive.

 

[daveb]

Starting from the least abrasive, Semichrome, then Flitz, then fine rust eraser and at last Barkeepers Friend. Or go full geek and do it with stones.

 

[Fynbo]

Bar Keepers Friend is very good for getting rid of patina.

 

[mikeeyS]

Another avenue if you have a bench grinder is a fine scotch brite wheel on Amazon. I use a fine wheel to rehab old old chisels, removes just the surface patina. I bought mine years ago but I think they run $40.

 

[tally-ho]

A scotch-brite wheel can be used to make a brushed finish on steel and even with hand, a sponge with scotch-brite will leave scratches on a blade, it will ruin the original finish. It also scratches glass and pirex utensils.

 

[M1k3]

Seems much to.... violent, for just removing patina. Now if they did want to redo the finish on it, sure, scotchbrite is an option.

 

[mikeeyS]

A scotch-brite wheel can be used to make a brushed finish on steel and even with hand, a sponge with scotch-brite will leave scratches on a blade, it will ruin the original finish. It also scratches glass and pirex utensils.

Have you ever used a FINE Scotch wheel ? My guess is no, there are many grades of scotch brite wheels. The finish on old chisels and plane irons that I rehab are done down to a mirror finish. I have no experience with Japanese steels and none with knives so my reply pertained to a different craft.

 

[tally-ho]

Only once so it doesn't count. It was about 15 years ago at my cousin's jeweller workshop where I restored some of my straight razors, before I own more dedicated tools, but I confess that I didn't know that there were different grades and I don't remember which grade I used.
Scratches were visible on razors that were originally mirror polished but not as obviously on razors with scratches pattern from the original grinding wheel, except when used perpendicularly.
Since then I changed completely my way of restoring straight razors, keeping most of the marks if there are not rust pittings.
But I did ban scotch-brite from my kitchen sink since it leaves marks on knives, particularly with soft san-mai.
Most people not having polishing wheel but more frequently kitchen grade scotch-brite pad or sponge, I would be cautious recommending it, but this is just personal preference.
I'm curious though as to which grade someone should be looking for ?