Lansky Multisharpener

E

EduardoA

Joined
Nov 17, 2016
Messages
11
I´ve got a Lansky Multisharpener, similar to the Spyder sharpener, a 4 inches triangular shaped bar.
After very little use it seems to be losing the ceramic layer. There are some bright metal streaks appearing which I tried to remove and they increased instead. I thought it was a solid ceramic bar that would last forever!
So I measured it and calculated the approximate volume and with the density of aluminum I checked the weight. The real weight of the bar is very near the one calculated for the aluminum, so I guess it really is not a solid piece of ceramic.
Aluminum is 2.720 g/cm3 and ceramic seems to be around 3.4 g/cm3.
Does anyone know the truth?
 
EduardoA said:
I´ve got a Lansky Multisharpener, similar to the Spyder sharpener, a 4 inches triangular shaped bar.
After very little use it seems to be losing the ceramic layer. There are some bright metal streaks appearing which I tried to remove and they increased instead. I thought it was a solid ceramic bar that would last forever!
So I measured it and calculated the approximate volume and with the density of aluminum I checked the weight. The real weight of the bar is very near the one calculated for the aluminum, so I guess it really is not a solid piece of ceramic.
Aluminum is 2.720 g/cm3 and ceramic seems to be around 3.4 g/cm3.
Does anyone know the truth?
Click to expand...
Hi,
Do you have a picture?
how did you try to remove the bright metal streaks?
What is the volume you approximated and the weight you measured?
 
It IS a solid ceramic bar. You won't remove 100% of the particles from the surface, but you can use an eraser to lift most of it off the surface. For a deep clean you can use a green abrasive pad and Bar Keeper's Friend powdered cleanser.
 
I´ve uploaded a picture to Google Drive:
https://drive.google.com/file/d/0B3BtkRi-p-addzlFY0RaeE9hS1E/view?usp=sharing
It´s difficult to evaluate with a loupe, moreso in a picture...
The volume in cm is: 10.1 x 1.23 x 1.12 /2 which multiplied by the aluminum density 2.7 g/cm3 equal app to 19 g. The real weight is 22 g, very near. The density of alumina ceramic seems to be around 3.4 g/cm3.
I´ve tried to clean it, but looking trough a loupe the bright area seems lower than the surface.
These things aren´t sold here. I have 2, one cost 30 dollars and the other was brought by a friend.
Thanks for the help.
 
Providing I don't have the model totally wrong, that's solid alumina ceramic. What I see in the photo is glazing from sharpening, and most of it should scrub off. As noted already, it's pretty much impossible to completely remove all of the steel particles from the surface, but it doesn't really impact the performance in any meaningful way.
 
EduardoA said:
I´ve uploaded a picture to Google Drive:
https://drive.google.com/file/d/0B3BtkRi-p-addzlFY0RaeE9hS1E/view?usp=sharing
It´s difficult to evaluate with a loupe, moreso in a picture...
The volume in cm is: 10.1 x 1.23 x 1.12 /2 which multiplied by the aluminum density 2.7 g/cm3 equal app to 19 g. The real weight is 22 g, very near. The density of alumina ceramic seems to be around 3.4 g/cm3.
I´ve tried to clean it, but looking trough a loupe the bright area seems lower than the surface.
These things aren´t sold here. I have 2, one cost 30 dollars and the other was brought by a friend.
Thanks for the help.
Click to expand...

Hi, ok thats some good math there
6.96 cubic centimeters
of aluminum is 18.8grams
but 27.49 grams -28.54 grams Alumina (aluminum oxide)

does that include the fish hook groove?

If you call that 2mm * 2mm * 10.1 mm,
now the volume is 6.556 cubic centimeters,
and you're down to 25.9 grams - 26.88 grams

The difference between 22 grams and ~26 grams is ~15 percent
Doesn't seem like a huge difference, and 15% porosity doesn't sound like too much for solid ceramic :)

but wait, you quoted 3.4 grams ...
it seems i've been using white fused alumina density range,

brown fused alumina is listed a 3.6 grams, that makes it
23.6 grams
or if the hook sharpener groove is 3mm
weight is 21.8 grams

So yeah, that loading does look shiny, but its probably just that, loading :)
 
Yes, thanks to all.
I´ve tried to clean it with rubber and with scotchbrite + barkeepers friend.
I´ll keep using it. I use to reserve it for small folding knives I care more, these sharpening stones are expensive and rare here. The Smith ceramic stone sold in USA for 3 dollars cost around 10 dollars here.
 
It's a very good ceramic sharpening tool that's small in size. I have many. One I cut 1/2" off of it with a diamond saw so it would fit into a mini-kit I have for the woods. It is definitely all ceramic. I have also sanded/rounded off all the sharp end corners off of mine ( doesn't affect use of the rod) so they wouldn't wear holes in the sheath pouches. They are very hard. I also ditched all the rubber end caps. They are pretty much useless as a guide , and prohibit full use of the triangular rod.
 
Hiwa, thanks for the clarification. I also find it very good and was sad thinking it was not solid. Hurrah, I can like them again.
I also remove the end caps for use and then replace after use.
Thanks very much.
 
You must log in or register to reply here.
Back
Top