Hi, I sharpen ALOT of 'VICTORY' brand fish filleting knives made in New Zealand. Mostly with thin 25cm blades. I was having fair results with the standard SG wheel, however since changing over to CBN wheels I am having trouble raising a bur. The steel is quite hard, or so it seems. Does anybody have any thoughts on maybe changing my technique or any other suggestions? The new CBN wheels work great on all the other knives I do for people. I am far from being an expert or a beginner,[ been sharpening for nearly 3 years now] so my technique is pretty well sorted.
Any help would be greatly appreciated.
Dan, Norfolk Island, South Pacific
Quote from: dankeelz on April 27, 2024, 02:02:47 AMHi, I sharpen ALOT of 'VICTORY' brand fish filleting knives made in New Zealand. Mostly with thin 25cm blades. I was having fair results with the standard SG wheel, however since changing over to CBN wheels I am having trouble raising a bur. The steel is quite hard, or so it seems. Does anybody have any thoughts on maybe changing my technique or any other suggestions? The new CBN wheels work great on all the other knives I do for people. I am far from being an expert or a beginner,[ been sharpening for nearly 3 years now] so my technique is pretty well sorted.
Any help would be greatly appreciated.
Dan, Norfolk Island, South Pacific
I think it may be the opposite of "quite hard"... their Catalogue says "The stainless steel blade hardness is 54-55 HRC" (https://victoryknives.co.nz/content/VK_2020_Catalogue_2021_Web.pdf). CBN wheels reportedly don't work well on softer steels. For example:
Quote from: https://info.eaglesuperabrasives.com/blog/why-cbn-is-the-superior-choice-for-grinding-steelLimited Application: While excellent for hard materials, CBN may not be the best choice for softer materials, where conventional abrasives might suffice.
(It's also mentioned on Rich Colvin's website (https://www.sharpeninghandbook.info/Grindstones.html).)
Thanks for your comment. I will just go back to using my SG wheels and try that. I thought someone would be able to help. Cheers regards
Dan
Dan,
I did an online srarch on how hard are Victory knives:
"People also ask
What steel does Victory knives use?
Victory contines to thrive by maintaining the highest standards in manufacture and materials, building on its reputation for unsurpassed quality. The stainless steel blade is made from German Krup steel, hardened to a hardness of 54-55 HRC.
https://www.huntgathergrow.com.au › ...
Victory Knives - Hunt Gather Grow"
I am no metalurgist, however, most kitchen knives seem to be in the 58 to 60 range. That would indicate to me that the steel in Victory knives is softer than typical and better suited to non superabrasive knives, meaning not CBN or diamond wheels.
I consider the Tormek online classes the most reliable source on Tormek. A frequent question in several of the classes is asking for a recommended wheel of choice for knives and chisels. The Tormek instructors have access to any of the Tormek wheels. They consistently recommend the SG-250.
I am also aware of extensive direct and indirect marketing of CBN wheels. CBN and diamond wheels have their place with the Tormek, but not especially with kitchen knives. I would suggest sorting your knives to be sorted. Use the SG-250 for the knives with softer steel. Make sure your SG-250 is well tuned with the TT-50 and stone grader, Then, switch to your superabrasive wheel for the knives with harder steel.
Ken
Second that.
First task in sharpening is knowing what you are dealing with.
If you can't identify the steel on a kitchen knife then assume it's of low hardness and progress from there.
At least you won't risk damaging expensive CBN or diamond wheels.
If you're not making progress on an unidentified steel you can always switch to super abrasives later.
Thank you both Ken S and Sir Amwell. That is EXACTLY what I am about to do with a new batch I just got today to sharpen. That is why this forum is such a great thing to utilize.
Regards
Dan
Quote from: Ken S on April 28, 2024, 09:07:44 PM...
I did an online srarch on how hard are Victory knives:
...
You could have just read my post (https://forum.tormek.com/index.php?msg=40286). ::) :D :D
(But at least we agreed.) ;D
I did read your post and replied to you with thanks. I have just re-done some of them just using and OLD/WORN [205mm] sg 250 for the rough cut and then used a newer sg250 [248mm] for the smooth cut. WOW! So much better and easier! So thank you again, cbwx34, Ken S, and Sir Amwell for all the help and advice.
Regards
Dan
Quote from: dankeelz on April 29, 2024, 04:32:34 AMI did read your post and replied to you with thanks. I have just re-done some of them just using and OLD/WORN [205mm] sg 250 for the rough cut and then used a newer sg250 [248mm] for the smooth cut. WOW! So much better and easier! So thank you again, cbwx34, Ken S, and Sir Amwell for all the help and advice.
Regards
Dan
Thanks... I was actually just razzin' Ken. :)
This does raise some questions though.
It is fairly well known I think that sharpening softer steels on CBN is inadvisable due to clogging effect.
Could the same be said of diamond?
If no then what are the properties of the two that gives rise to this?
Quote from: Sir Amwell on April 29, 2024, 08:34:17 PMIt is fairly well known I think that sharpening softer steels on CBN is inadvisable due to clogging effect.
I remember learning this when I was selling engineering supplies in about 1980. This is because the softer materials tend to "rub" off and clog the wheel. The softer grinding materials such as aluminium oxide does the same but because it is softer it will wear away more quickly preventing clogging. It can clog but can be dressed.
A question arises. Why do the Victory brand fish filleting knives use a softer steel? Is it to make sharpening on-the-go easier? Do they sacrifice hardness so they can get improved ease of sharpening, improved ability to stay sharp, improved ability to resist staining?
Quote from: Herman Trivilino on May 05, 2024, 08:26:05 AMA question arises. Why do the Victory brand fish filleting knives use a softer steel? Is it to make sharpening on-the-go easier? Do they sacrifice hardness so they can get improved ease of sharpening, improved ability to stay sharp, improved ability to resist staining?
I'm gonna go with co$t.
Quote from: Herman Trivilino on May 05, 2024, 08:26:05 AMA question arises. Why do the Victory brand fish filleting knives use a softer steel? Is it to make sharpening on-the-go easier? Do they sacrifice hardness so they can get improved ease of sharpening, improved ability to stay sharp, improved ability to resist staining?
Maybe more flexibility?