thinning knives

So I have accumulated a lot of knives and stones over the last year or so in the name of experimenting. I enjoy sharpening and continue to improve but thinning is something that seems to take me a really long time. I have primarily been using diamond plates to do this but they feel like they are wearing out rather quickly and feel as though they arent working as effectively as they were brand new. I guess with such a large surface area to grind its not a big surprise. I also own a beston 500, a pink brick and sigma power 2 400 grit. The sigma and pink brick seem to dish fairly quickly which can be frustrating and the beston feels like it's working fairly slowly with some knives.

Im assuming this is a normal experience but I was wondering what everyone else uses to thin out their blades? Does anyone have any recommendations short of a belt sander (Which I spontaneously bought and have had issues with)? I'm trying to be efficient and get this done quickly and im growing weary of cutting up my hands pretty frequently trying to get it done. What's the best approach to doing this? Should I use a shitload of pressure on the beston and try to smile about it? Maybe I should just stop trying to thin my knives to much.

Are these the knives you're trying to thin?
Suisin inox honyaki 270mm wagyuto
watanabe blue 2 270mm wagyuto
masamoto ks white 2 270mm wagyuto
sugimoto cm 240mm wagyuto
tanaka ginsanko 210mm wagyuto
sakai yusuke white 2 270mm sujihiki
tanaka ginsanko 150mm petty
suisin inox honyaki 210mm petty
jck nashiji white 1 130mm petty
dojo blue super 90mm petty
masamoto ks white 2 330mm yanagi
tojiro white 2 150mm yanagi

If serious steal removal is needed I would start lower then 400. Something like 220grit for a waterstone. I am not sure there are any lower grit water stones.
Lately, I really like the Norton Coarse India (http://www.sharpeningsupplies.com/Norton-India-Bench-Stone-8-x-3-P23C25.aspx ) for the time I need to remove metal. It is quite fast (~grit 130) and dishes veeeery slow. You do not need to use oil, with just water or nothing at all it works great. When it clogs, pop it in the dishwasher and the stone cuts again.

Some of those knives, yes but ive got some additional knives and sold off some of them. At the moment im thinning a yoshikane skd (finished one side), the masamoto ks, tanaka petty, the watanabe (almost finished- just need to even out the right side) , a few carbonext gyutos, the yusuke suji plus the suisin and a kono hd. I originally just wanted to polish up the suisin, yusuke and kono about a 1/3 up the blade face but eventually went coarser and coarser. Scratched up the kono and watanabe annoyingly. Im finding that the stainless and semi stainless knives take a lot longer than the carbons. The clad knives seem to get more difficult the closer I get to the core steel or maybe it just feels like my stones arent working as quickly as the surface area gets larger where im thinning if that makes sense. Trying to polish out scratches is annoying at times too. Im guessing im trying to rush through the grits too fast

Just curious what problems are you having with the belt sander? A 220 belt should cut pretty fast and not get you into any trouble too easy, and I should think it would leave you with something you can finish up quick on the stones and buffing wheel. Though admittedly I've never done a cosmetic job on a knife myself.

Rick

I use a 220 grit belt also. Set up the grinder at 10 degrees vertically so that as long as i hold the blade perpendicular to ground, I shld be grinding at 10 degrees. There are times that i try to get it closer. You can try taping the spine if so desired and setting the angle of the grinder vertically at a lower angle say at 7 degrees if desired.

For grinding anything wider than 3mm from the edge, I have always preferred sandpaper 150 grit on a block with a soft leather for a start. Bringing the abrasive to the steel is easier than steel to abrasives as it allows you granular control. For the latter, it is normally over a few sessions.

Good luck.

rgds d

The belt sander needs some maintenance.. it's been jamming up on me and been rather loud. I did get some use out of it before which made things a lot easier. Seeing as I had never used one before I don't really know how to go about fixing it. I guess I should just get it serviced or something. Thanks for the suggestions! I might try out this norton stone whilst I figure out how to get the sander working again

zitangy said:

I use a 220 grit belt also. Set up the grinder at 10 degrees vertically so that as long as i hold the blade perpendicular to ground, I shld be grinding at 10 degrees. There are times that i try to get it closer. You can try taping the spine if so desired and setting the angle of the grinder vertically at a lower angle say at 7 degrees if desired.

For grinding anything wider than 3mm from the edge, I have always preferred sandpaper 150 grit on a block with a soft leather for a start. Bringing the abrasive to the steel is easier than steel to abrasives as it allows you granular control. For the latter, it is normally over a few sessions.

Good luck.

rgds d

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I have used a belt sander mainly for 0 to maybe as high as 5deg angles, mainly were you are working the upper 90% of the profile to do serious all-around thinning. I wouldn't trust myself much past 5deg unless it was a 1200 belt.


Rick

masibu said:

The belt sander needs some maintenance.. it's been jamming up on me and been rather loud. I did get some use out of it before which made things a lot easier. Seeing as I had never used one before I don't really know how to go about fixing it. I guess I should just get it serviced or something. Thanks for the suggestions! I might try out this norton stone whilst I figure out how to get the sander working again

Click to expand...

If the belt tracking ok I'd guess you have a junk bearing or 2.


Rick

Either of those wouldn't surprise me. As long as it's cheap to get fixed up I'll probably get onto it soon. It certainly makes life easier. I estimate that im going for about 2-5 degrees or so on my knives for thinning, depending on the knife. Im not exactly a protractor though, I'm relying on visuals.

I use a shapton pro 120 - leaves a uniform pattern that is easily removed step by step onwards.
I stopped using diamomdplates on knives; it leaves a very rough finish and uneavenly scratchpattern plus deep scratches.
So the diamond is only for flattening the stones in my house
And oh yes,the impatience is much harder to deal with than just buying new stones...

Cheers...

For serious thinning you need to drop lower than a 400. The sigma is a great stone designed to bridge the gap from your lower grits to a medium grit.

In my experience diamond stones do loose their effectiveness after a few uses. Once you shave/cut off the first layer if abrassives they usually jump up in grit. For example I bought a #120 grit high end diamond plate for around $100 but after a few knives it feels more like a #300 grit when I use it.