Crox seems common here but anyone using iron oxide 0.1 micron paste?

[RayClem]

Thanks, that's a really detailed explanation.
Given that iron oxide appears to be finer and softer than CrOx, is it possible to use it for daily stropping? Daily stropping with CrOx weakens the edge (I think?) so is the risk the same with iron oxide assuming 50 laps or so in between shaves?
Since iron oxide is softer and finer, is it wise to put the paste on the other side of one's regular strop, since contamination would not -in theory- be as detrimental than if CrOx was the contaminant?

Any abrasive at 0.5 micron is going to remove more metal than you want if used daily. I think some people are maintaining their razors nearly indefinitely using 0.1 micron abrasives. You might need more laps using iron oxide than CBN or diamond, but it should work without removing an excessive amount of metal unless you are really going overboard with the laps.

 

[Darth Scandalous]

Ferric oxide has been used as a rouge or polishing compound for a long, long time. As @RayClem said, it's pretty gentle. I would question the 0.1 micron particle size though. Most vendors don't call out the particle size and the ones that do usually have it around 1 micron. I saw one selling it for polishing optics that claimed 0.7 micron.

I also wonder how friable it is, that could enhance the polishing effect.

 

[nicepatina]

There are several forms of iron oxide, but I presume the abrasive is Fe2O3, also known as hematite. It has a Mhos hardness around 6, which is around the same level as hardened steel in a razor. Thus, this is an "iron sharpens iron" type of sharpening. It is like sharpening your chef knife on on a knife steel rather than on a whetstone or ceramic rod. In contrast, chromium oxide is much harder, around 8 on the Mohs scale as is cerium oxide, frequently used to polish glass. Harder yet are aluminum oxide (corundum), silicon carbide, cubic boron nitride, and finally diamond, which is the hardest mineral known to man at this time.

Thus, using iron oxide is a very gentile way of improving the edge of your razor. Cerium oxide and chromium oxide will be slightly more aggressive. Aluminum oxide, Silicon carbide, cubic boron nitride and diamond need to be used with care.

I use cubic boron nitride in particle sizes of 0.5 micron, 0.25 micron, and 0.1 micron to polish the edges of my straight razors.

There is certainly nothing wrong with using 0.1 micron iron oxide (sometimes called jeweler's rouge). The abrasive works quickly to polish softer metals like gold, silver, copper, and tin often used in jewelry. It will work far less quickly on hardened steel, especially if you have one made of super hard steel like Thiers Issard C135 "Carbonsong" steel or Japanese steel blades Because iron oxide is so gentile, you need to use other abrasives such as chromium oxide to be sure the razor's edge is sharp enough. Then the iron oxide can provide the final polish. If you try to take an edge directly from a 10-12K hone and finish it with iron oxide, you are likely to become frustrated at how slowly the abrasive works.

An explanation like this is why I created this thread. Amazing and informative! It gives me a better understanding of the pastes I have for sure. I think I may experiment with being more liberal in my strop count on the iron oxide and see how it goes.

 

[nicepatina]

Ferric oxide has been used as a rouge or polishing compound for a long, long time. As @RayClem said, it's pretty gentle. I would question the 0.1 micron particle size though. Most vendors don't call out the particle size and the ones that do usually have it around 1 micron. I saw one selling it for polishing optics that claimed 0.7 micron.

I also wonder how friable it is, that could enhance the polishing effect.

The iron oxide paste that I got was from Maggardrazors. They seem to be trustworthy for the most part in this community it seems. They listed it as 0.1 micron and their crox at 0.5 micron, which I also got from them. It would be really weird if the iron oxide they advertise is not finer than their 0.5 micron crox. Maybe the crox is not really 0.5 micron either, but as long as the iron oxide is finer than their crox I guess its all good with me.

 

[Darth Scandalous]

The iron oxide paste that I got was from Maggardrazors. They seem to be trustworthy for the most part in this community it seems. They listed it as 0.1 micron and their crox at 0.5 micron, which I also got from them. It would be really weird if the iron oxide they advertise is not finer than their 0.5 micron crox. Maybe the crox is not really 0.5 micron either, but as long as the iron oxide is finer than their crox I guess its all good with me.

Yeah, I don't think there's any question that the CrOx to FeOx progression works pretty well. And Brad Maggard seems to be a stand up guy.