Thread: Chromium questions

Originally Posted by gaucho

Hi there,

good to see people from Brazil here. Where did you get the chromium oxide?
Take care, since they are not all the same.

Best,
Felipe

In Brazil you can get chromium oxide very easyly in any arts and crafts store that has suplies for porcelain painting. Chromiun oxide (in powder) is used to "paint" porcelain. You should get a bottle of copaíba oil also, as it is what people use around here to "dissolve" or "dilute" the chromoum oxide.

Oh, and the chromium oxide is called "Verde do óxido de Cromo" in those stores. Other thing: the copaíba oil will leave a really nice "woody" smell on your strop. I use Chromium oxide on a old leather belt to keep my kitchen knifes scary sharp.

Yes, but there is a difference in the size of the particle. You can find powder that is 320 mesh, 400 mesh, etc. from the chemical industry. What you should get is a good quality micronized chromium. With particles of a single size. Pure, and with very low retention.

Of course, if you get powder you must put into a suspension. Water based, oil based it´s your choice.

The information I found in this forum gives me the idea that all chromium is 0.5 micron, what to my knowledge is not correct. I use two sizes 1 micron and 0.5 micron.

Chromium is used to manufacture polishing compounds at different levels of technical demand. You can find some compounds refered as green chrome (usually they look like a gold bar) that are a mix of abrasive particles of different sizes and types. I think the finest thing you can find are pastes for sample preparation for laboratory analysis. This is probably the application that will demand the most.

You can also use diamonds that comes at different particle sizes, uniformity, suspension, quality, etc. Or even micronized aluminium (a white powder, not green), that can go down to 0.3 micron if I´m not wrong. Of course, they all look different at microscopic. I only use chromium.


Best,
Felipe

Felipe---Felipe here--LOL Phillip that is. Is the oil you mentioned the same as the standard mineral oil we use here? Fairly thick and clear etc.

Originally Posted by Gunner777

Felipe---Felipe here--LOL Phillip that is. Is the oil you mentioned the same as the standard mineral oil we use here? Fairly thick and clear etc.

Mineral oil is just like that around here.

Gotcha I thought it would be just a different name.

Originally Posted by gaucho

The information I found in this forum gives me the idea that all chromium is 0.5 micron, what to my knowledge is not correct. I use two sizes 1 micron and 0.5 micron.

I thought any chromium powder would be 0.5 micron (like it was the particle size of chromium oxide).

Well, the powder I use in my kitchen knifes leaves a mirror (not near mirror, real mirror) finish on the edge, so it should be fine.

Anyway, the kit Gunner has sent me has some 0.5 Crox in it, I'll test booth my "painting" crox and the stroping crox to see if they have any sensible diference. I'll post my findings here.

Originally Posted by cegadede

I thought any chromium powder would be 0.5 micron (like it was the particle size of chromium oxide).

Well, the powder I use in my kitchen knifes leaves a mirror (not near mirror, real mirror) finish on the edge, so it should be fine.

Anyway, the kit Gunner has sent me has some 0.5 Crox in it, I'll test booth my "painting" crox and the stroping crox to see if they have any sensible diference. I'll post my findings here.

A mirror finish is something that depends only on the scale of observation.
A norton 8k gives you a "mirror finish", as probably would stones with grits like 6k, 5k. With a bad chromium, makes no sense using it after a good stone like the norton 8k.

Best,
Felipe

Originally Posted by gaucho

A mirror finish is something that depends only on the scale of observation.
A norton 8k gives you a "mirror finish", as probably would stones with grits like 6k, 5k. With a bad chromium, makes no sense using it after a good stone like the norton 8k.

Best,
Felipe

As I said, I'll test booth and let you know my impressions, after all, if "porcelain painting" crox have satisfatory results (on par with "stroping crox", that is) it will be great news, as we, Brazilians, won't have to import the stuff, just use the readly avaiable (and really cheap) product.