Thread: Consumer Alert: Chromium oxide bars, or not?

Hey guys, I've had a recent experience that everyone here needs to know about. A few months ago, I was in the market for some chromium oxide, and I couldn't find anywhere that had the Hand American products in stock, so I researched on most of the major woodworking retailers online, and found that many of them sell bars of honing compound.

These bars are green and waxy looking, usually about five inches in length or so. Most of them look pretty much just like this:


They are typically advertised as being "Chromium Oxide" honing compound. I didn't like the fact that most of the places didn't give a particle size in microns, so I shopped around. I ended up with the "Veritas" honing compound sold by Lee Valley Tools, because of this sentence in the description on their website:

"It is primarily chromium oxide admixed with other fine abrasives (0.5 micron particle size) to give the best combination of cutting speed and fine finish."

0.5 micron is what I was shooting for, so I bought it and it was great for my kitchen knives (I got into straights from sharp kitchen knives... just a natural progression, I guess!).

When I started using it for straights, I got good shaves off of it, or so I thought. I would follow my Chinese 12k with the polishing compound on a paddle strop of my own making, and things were ok. After a while, I found myself enjoying my shaves right off of the 12k better than with the compound, and under the microscope, my bevels didn't look as smooth as what I found on the Tim Zowada pictures.

I emailed Lee Valley's customer service department, and asked for the Materials Safety Data Sheet on the compound, and they sent it to me, and it was VERY reavealing. The Veritas compound, which they advertise as "primarily chromium oxide" actually has the following composition as seen in the Green/Red box in the pic below.






The veritas bar is between 50 and 60 percent Aluminum Oxide!!! So, the next question that came to mind was "Is the particle size held to .5 micron?" To find this out, I decided to contact Formax Manufacturing, the company that makes the honing compound (They also make the "Microfine" honing compound like you find at woodcraft.com). I emailed the customer service, and who replied but Andrew Johnston, whose name is on the MSDS sheet. I figured he would be the right guy to ask about the particle size of the abrasive.

Here is our email conversation:

----- Original Message -----
From: ben R.
To: sales@formaxmfg.com
Sent: Friday, November 07, 2008 1:47 AM
Subject: Green rouge - particle size


Hi, I've purchased some of your green rouge sold under the "Veritas" brand at Lee Valley Tools. I understand that this is a special formulation of chromium oxide (20 - 30 percent), aluminum oxide (50 - 60 percent), triglycerides and animal fats (15 - 17 percent) and mineral wax (3 - 5 percent) as reported in the MSDS sheet.

I'd be very appreciative if you could tell me the particle size (in microns, preferably) of the aluminum oxide used in this product. I use this as the final step of honing straight razors and am curious about how fine the abrasive is. I am already aware that chromium oxide is typically 0.5 microns, I'm just wondering about the aluminum oxide.

Thanks for your time,

Benjamin B. Rivenbark
Ben325e@XXXXXX

From: Andrew Johnston <sales@formaxmfg.com>
To: ben R. <ben325e@XXXXXX>
Sent: Friday, November 7, 2008 9:15:47 AM
Subject: Benjamin Rivenbark Re: Green rouge - particle size 11.7.08

DIV { MARGIN:0px;} Benjamin B. Rivenbark
Ben325e@XXXXX.com

The Green Honing compound does contains two different abrasives. One abrasive is a Calcined Alumina and the mesh size would be listed as -300. Actually that’s a trade determination that simply says nothing in the abrasive is coarser than 300 grit. However, that same specification would see fines in that same abrasive going all the way down to .5 micron. The Green compound is also composed of chromium oxide that has a particular affinity for buffing steels, especially stainless.

Andrew
sales@formaxmfg.com

----- Original Message -----
From: ben R.
To: Andrew Johnston
Sent: Friday, November 14, 2008 1:07 PM
Subject: Re: Benjamin Rivenbark Re: Green rouge - particle size 11.7.08


Thanks for your reply, Andrew. Am I correct in understanding then that the Calcined Alumina could contain particles larger than .5 micron? For example, the green honing rouge from Mcmaster-Carr is listed in their catalog as having a 2 micron average particle size, and their bar is also Alumina and Chromium oxide.

-300 mesh indicates that each particle is .003333 inches or smaller, which leaves the largest particle that would pass through a 300 mesh screen 169 times larger than .5 microns.

Basically, I am trying to find out the largest particle contained in the green honing compound as distributed by Lee Valley tools. They advertise that the abrasives in their green bar are 0.5 micron or smaller, and it just doesn't seem correct to me, as I get a much finer finish on straight razors using other compounds. Also, when viewed under a microscope, the scratch pattern left by the Veritas honing compound is more significant than one would expect when compared to other abrasives, such as the Shapton 30000 grit ceramic hone, which has an average particle size of .49 microns.

So, I guess the question I am after is this: Does the Green honing compound contain any abrasives larger than .5 microns?

Thanks for all your help,


Benjamin B. Rivenbark

Dear Sir,

Yes. The product could contain paticles larger than .5 micron.

Andrew

If you have bought the Veritas Honing compound and would like to return it for a full refund including being refunded for your original shipping charge as well as not paying postage to ship it back, click here: http://www.leevalley.com/home/ReturnExchangeFormUS.pdf

A gentleman at Lee Valley has told me he would have the item description looked into and edited for the future.

I assume that most other places that sell "Chromium oxide" bars also have mostly aluminum oxide in them. When I performed a MSDS search on such bars, I found many that contained only 5 to 10 percent chromium oxide.

For example, McMaster-Carr sells a chromium oxide bar that has an average particle size of TWO microns! (Seraphim, did you *ahem* recommend *ahem ahem* this bar to someone on badger and blade? )

Bigbadwulf - I believe you bought the Veritas honing compound on my recommendation a few weeks ago - I'm buying the Hand American chromium oxide, and will gladly send you a good bit for free, as well as a paddle strop made with Hand American leather as an apology! PM me your address, and I'll send it out when my order comes in.

The moral of the Story? Buy the Hand American Chromium oxide. Japaneseknifesharpening.com stocks it. I'm sure Dave Martell will be happy to read my post!!

Cheers,