There was a question on old steels and surface. There is no problem that there is much patina on them or that there are some minor pitting. There is also no problem that the surface is a bit more
worn some places. The old types with fine surface works very well when worn. The only problem is if you got notches in the surface that would cause the edge to hit during the motion. I recommend testing it out because it is very effective as said. The reason
for why carbon steel and similar gets patina is because it reacts to substances and food stuffs over time. It is not stainless so it will rust and corrode. Carbon steels will get a patina from age no matter what as well. That the fine surface is a bit in chaos
with micro notches, lines and structures is only a big advantage.
It is also my impression that sharpening steels that are traditional is bare minimum maintenance and because it is not like
the honing rod that are abrasive. These removes much more metal and it is very different.
about the steeling i would like to mention what’s been my topic for a long time about the pressure you apply during maintenance. I am not a fan of round diamond coated sharpening rods on a flat edge. They are great on serrated and wavy edge knives. When
you use traditional sharpening steels with fine-lines along the design or similar structures it will cause positive advantages on blades. It is round and therefor it will cause very high pressure if you are hard handed during the motion. Moderate pressure
is what you need and sliding the edge along the design. If you use extra abrasive diamond coated rods then you need to practice a bit before perfect. This removes much more metal and cannot be used as frequent as traditional ones because you will wear the
knife to fast. There are ceramic rods or diamond coated ones with extra fine surface and these can be used with good results. It will maintain, correct and sharpen all the same. That is very effective. However it is not as carefully as flat stones because
of the difference in contact area. From experience it is because the traditional steels are bare minimum that you do not have to sharpen the knives so often and you save the edge for a longer time. From time to time it is unavoidable that you have to sharpen
further with flat stones. I recommend fine 600 grit for most tasks. If you use fully polished surface sharpening steels then these will correct the edge but they are not as effective removing metal, burr and substances.