Salmon knife? - long and thin blade

[BradGE]

Hi All,

A new one for me...  This is a salmon knife brought to me for sharpening and I've never done something so narrow before...  The blade looks to have been sharpened extensively to the point where it's now very thin, and combined with its length makes this tricky to set up...  The only way I can think to get a grip on it is with the SVM-00 as per my photo... But it is probably going to flex when I get out towards the tip.  I could possibly grip directly on the blade if I went for a very high angle (>25 dps) but I don't think that edge would suit its intended use...  And with the curved heel I'm wishing I already had my PPC.  Any ideas on how to tackle this would be greatly appreciated!

Thanks and all the best,

Brad

[micha]

Brad,

wow, that thing looks really narrow. As for the bending, the first thought is using the SVM-140. But then I'm not sure if you could clamp it at all because it's so narrow, and it's difficult to tell the real width from the picture. If you don't have the long knife jig, doing it freehand on a platform could be an alternative. A small knife rest like Herman's would help here even more. There are several ideas for building one around here.

In any case you will have to round the corners of your wheel to get the heel properly done, if your wheel has sharp corners you'll probably end up with some notches in that area. (been there, done that...)

Mike

[BradGE]

Thank you Mike... I do actually have the long knife jig, and if I just clamp the very edge (See photo) I can manage about 24dps without grinding the jig too...  I'll try that and see how it goes sharpness-wise.

I plan to round the corners off on my SG250 since I mainly use diamond stones these days... But looking forward to when I get my PPC.

Best,

Brad

[micha]

Now that doesn't look so bad. I think you could even gain a little more protrusion if you clamp it so that the straight portion of the edge is more parallel to edge of the jig. Does that make any sense?
In your picture that would mean putting the knife's tip closer to the ruler.

Just because I referred to the small knife rest before, here's some information from the Oldies but Goldies series

Hermans knife rest: https://forum.tormek.com/index.php?topic=1592.0
and a related Video: https://www.youtube.com/watch?v=AcWAkQmoU8c

[cbwx34]

Herman's Knife Rest is probably the best solution for an angle guide in this case.

Another option is to turn the machine around, (so the wheel is turning away from you), and freehand it.  You can "set the angle" by using the technique Steve Bottorff demonstrates on the paper wheels HERE.  This would allow you to work the knife near the heel, and also keep pressure on the blade with your fingers as you slide it across so it won't flex, and also sharpen at a lower angle than you can with the Tormek jig.  (Takes a bit of practice, so maybe for future reference... but give it a try).

Edit:  This shows it a bit....  https://www.youtube.com/watch?v=KrhZULmd18g

[BradGE]

I love that knife rest by Herman - will have to make myself one soon. 

I tried with the long knife jig and managed 24.7dps... Wide for a slicer but created a decent edge - 170 BESS. 

Thank you cbwx34 - I'm going to try that freehand technique on another knife and if my hands are steady enough then I'll try it on this salmon knife.  I'd like to get it down around 15dps and sub-100 BESS, though I only have the standard Tormek honing paste for now so I don't hold hope of getting to silly BESS levels.

[micha]

I'm not good a freehand grinding, at least the results don't match my self-imposed standards.

But something inbetween came to my mind, and it works pretty well. I use shims and clamp the thin knife between these.
(Please ignore the tip being covered by the shims, that knife is just an example for a narrow blade.)
The principle is simple, you'll still have to pay attention to not changing the angle, as this kind of clamping allows for some twist, but still gives basic control of the USB/wheel-distance.

Adding an additional shim as thick as the knife's spine should even allow to clamp it quite firmly and sturdy.

[Welkcar]

I think that 'salmon' knife has been sharpened way too many times, or too aggresively. Does not look like ant salmon knife pic I can find. I would reccomend that your customer get a new one and pitch that dagger.