Becker K&T: BK7 & BK11 ... odd observations

[rhino]

I have BK7 from when they were first made available. I also have a BK11 from spring of last year.

I've noticed that after I sharpen the BK11, if I don't use it and it just sits around for a few weeks, the edge is noticably less sharp. I assume this is because of oxidation on the exposed edge.

The weird thing is, this doesn't seem to happen to my BK7.

Any ideas why? Did Camillus/BK&T use a different allow a few years ago? Is there a significantly different heat treatment between the two?

Or is it just one of those weird things without a good explanation?

 

[bigbcustom]

I have both, and I don't experience the problem you are describing. After any use or sharpening session, I treat them with a marine tuff cloth before putting them away. As for why you are seeing your bk11 dull more than the 7, I don't know for sure, but I would guess that you maybe put a finer edge on your 11 which equates to a finer cross section at the very edge which would be effected more quickly by any oxidation that did occur. FWIW I sharpen my BK7 @ 30 degrees with a 40 degree micro bevel, and my BK11 with a 20 degree primary bevel with a 30 degree micro bevel. Of course, at least in the case of the 11, it sees use weekly, and I sharpen it whenever it gets to the point it won't easily shave hair. The BK7 is in my round robin hiking knife pool which means it will only see use anywhere from bi weekly to bi monthly depending on the time of year. It gets much rougher use, so it usually gets sharpened right after it's last use.

 

[Phil Gibbs]

Good thoughts bigb!

As far as I know the steel & Heat Treatments have not changed at all.

Using a Tuff Cloth is ALWAYS a good idea!

 

[rhino]

Thanks for the feedback, guys. A silicone cloth is a great idea.

I reprofiled the edges on both to get them as thin as I could given the overall thickness of the respective blades, so I'm not sure what exact angles they are (I do it by hand).

My BK7 rides in the truck for emergency use. My Necker is a "sometimes carry," but rarely used. I probably should carry it all the time as it's one of the most potentially useful tools I own.

Thanks again!