Epic Knife Sharpening Fail!

[darita]

 ...So I've sharpened chisels and planes and those come out great.  I can get the edge so nice, I can barely see any grind marks, under magnification. 
Now for the fail part...I went to Walmart and picked up a couple of practice kitchen knives, as for some reason, the wife does not like sharp knives. I haven't sharpened any of her knives in 10 years. Anyhow, I got all the jig stuff right, only I had a hard time getting a burr, but I did finally get it.  Thing is, I had a hard time getting the grind surface even on both sides of the blade.  Taking the same number of strokes on both sides didn't work for me. 
So now for honing...my angle was either too much or too little...too much or too little...too much or too little...  Also, I never could get the grind mark out to get that super nice polish.  Under mag, I could only get about 20% of the marks out.  Yes, the knife cut paper fairly easy, but nowhere near the planes or chisels that I've done. 
Right now, I'm kinda lost and feel like, if I don't have someone to hold my hand thru the process, I don't know what to correct and or how to correct it.   

[jeffs55]

If your blade is more than 1/8 inch thick across the spine and maybe a little less, you cannot get the grind even on both sides of the blade. It is a Tormek design flaw. I suppose you could if you did one side and removed the knife and then refastened it opposite the original way but who is going to do that?

[darita]

If your blade is more than 1/8 inch thick across the spine and maybe a little less, you cannot get the grind even on both sides of the blade. It is a Tormek design flaw. I suppose you could if you did one side and removed the knife and then refastened it opposite the original way but who is going to do that?

Ah, Ha!!!  Ok...that's one for me, not that it matters to have them even...does it?

[Ken S]

Your Walmart knives should fall within the very acceptable thickness range. Most kitchen knives are flat now, even quality knives. Flat knives are easier (less expensive) to manufacture. Also, thinner flat knives cut more easily, a plus.

I would concentrate on getting your knives sharp and not be concerned at this point about matching bevels. Work on one knife at a time, making sure you raise a burr. Spend enough time with your first knife to get it sharp. Speed will follow as you get more experience.

Your wife's fear of sharp knives is a common misconception. The problem with using dull knives is that more force is required to cut with them. If a dull knife slips, there is more force behind the slip. A sharp knife cuts easily with less force. A sharp knife really is safer to use.

Ken

[darita]

Thanks Ken.  Good advice.  Is it normal to have some grind marks showing, even after honing? 

[jeffs55]

In my experience, grinding with a finely graded grindstone sufficiently long enough followed by a good stropping will only leave barely perceptible scratches if any. Load your honing wheel with compound not so much that it sloughs off but real good coverage. If the compound falls off too easily, put a couple or three drops, not squirts more oil on it. Space the drops around the wheel. Sneak up on the edge when honing. Start from the spine and go toward the edge never exceeding the angle used to sharpen the edge in the first place. IE, if the edge was sharpened at 25 degrees, then the honing should not be done at 26 degrees. You will roll the edge which means dull it.

[darita]

I think I might try grinding on the other side of the wheel, with the wheel rotating away from the blade.  I feel that way I can lighten up on the down pressure and maybe finish with lighter cuts.  With the blade rotating toward the blade, I have to keep significant pressure on the edge, to keep the edge from catching.

[jeffs55]

It is not the pressure on the blade that catches it, it is the angle of sharpening. Of course, there is such a thing as enough pressure to make it catch but if you are pressing that hard and the angle is not too steep, you are going to stop the wheel. Sharpening with rotation towards you is more aggressive, just do not make the angle too steep. The lighter the pressure the less the grind the longer it takes. All you need is a finely graded wheel that is properly dressed, that is; it has been trued before becoming too glazed over. A finely graded stone is not going to gouge your knife and the honing wheel will make it shine.

[Ken S]

Derek,

Grind one of your practice chisels. Set it aside. Set up a second practice chisel in the exact same way and grind as you did with the first chisel, with the only change being using a noticeably lighter grinding pressure, especially at the end. Compare the scratch pattern in the two chisels.

Grinding pressure is one of the great versatility variables of the Tormek.

Ken

[darita]

Ken, I may try that next.  I just tried grinding a knife on the trailing side.  I found it to be a lot more controllable and I was able to grind with much less pressure.  That said, I'm still finding it difficult to strop away the grind marks.  I've tried to dress the stone fine, but maybe I"m not giving that dressing stone enough pressure or not doing it long enough.  I'll keep at it.
Just for comparison, I sharpened the same knife with traditional stones.  So far, the results are close, but I think because of the presents of grind marks, sharpening with the Tormek is still behind the traditional.  I'm still working it though, so I hope I can improve things with the Tormek.  I'm sure I'm not doing something right...I just can't find what it is.

[timpaulgeorge]

Maybe upload a video of you going through the steps on youtube or something and link it? Might help to diagnose the issue.

[Pastor_Zatx]

Part of the issue may be the cheap knife itself. Some of the "steels" used in the ultra-cheap cutlery sold in big-box discount stores barely qualify as pot metal. Their tempering process can be so incredibly inconsistent that producing good results with your sharpener may just end up producing frustration rather than sharp edges.

It's kind of like learning to play the guitar; most people that are given (or purchase) a cheap starter guitar never end up learning to play it.  The quality is so low that it won't hold its tune and they get frustrated, thinking they can't learn the proper techniques when all they really needed was a nicer mid-level instrument.

I'm not saying you should practice on a $1,000 custom folder, but maybe pick out one of your wife's better kitchen knives that she uses less than the others and practice on it. If you ruin it (though I don't see how), then you'll have an excuse to buy new knives!

Also, there may be two other factors. Someone already mentioned the limitations of the Tormek clamp/jig. This characteristic is due to the knife not being perfectly centered in the clamp. You can check and adjust this by using tape or some other media on the blade to even it up. The second factor is getting the knife in the exact same spot on the stone when you go side to side. You can use a flat plate jig, laser line, or some other contraption to assist your aim.