Author Topic: Rock hard felt wheel  (Read 5433 times)

Offline bgtklbx

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Rock hard felt wheel
« on: June 20, 2020, 01:07:29 am »
I’m using a T8 with the standard stone and a half speed 8 inch grinder with 2 ten inch slotted paper wheels. Every time I get a knife really nice and sharp (105-150) on a BESS tester and then get the idea to finish up with a rock hard felt wheel used on the Tormek at slow speed with 1micron diamond spray my edge goes south really bad.  (280) BESS.
So I’m done with that thing forever.  Done finished.
I can bring the numbers back with the paper wheels. Anyone have an idea why the felt wheel dulls the edge? I like to know if possible what happens, even if I’ll never use it again. I’ve tried exact angle and higher and lower.  Btw I use the knife grinders software with angle supports on the paper wheels and the frontal vertical base for the felt.
To add insult to injury the felt polished a “tiger stripe” into the mirror finish which the paper polished back out.

Offline cbwx34

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Re: Rock hard felt wheel
« Reply #1 on: June 20, 2020, 01:36:31 am »
I’m using a T8 with the standard stone and a half speed 8 inch grinder with 2 ten inch slotted paper wheels. Every time I get a knife really nice and sharp (105-150) on a BESS tester and then get the idea to finish up with a rock hard felt wheel used on the Tormek at slow speed with 1micron diamond spray my edge goes south really bad.  (280) BESS.
So I’m done with that thing forever.  Done finished.
I can bring the numbers back with the paper wheels. Anyone have an idea why the felt wheel dulls the edge? I like to know if possible what happens, even if I’ll never use it again. I’ve tried exact angle and higher and lower.  Btw I use the knife grinders software with angle supports on the paper wheels and the frontal vertical base for the felt.
To add insult to injury the felt polished a “tiger stripe” into the mirror finish which the paper polished back out.

Haven't used the felt wheels... so I'll just give you a couple of ideas...

Pressure can be an edge killer on a wheel that has give to it... so try as light a pressure as possible.  And even though you're using the software to set the angle... mark the edge with a Sharpie between steps, and be sure you're hitting where you want.  (Never hurts to double check).

You sound frustrated (and don't blame you), so taking a break is a good idea.  You're getting knives sharp, and as I've said before... there are many paths. :) 
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Offline Jan

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Re: Rock hard felt wheel
« Reply #2 on: June 20, 2020, 09:17:54 am »
I agree with CB. I would look for an error in setting the angle for the felt wheel. You can also try to use an alternative sw, e.g. TormekCalc2. Good luck.

Jan

Offline cbwx34

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Re: Rock hard felt wheel
« Reply #3 on: June 20, 2020, 02:01:10 pm »
I agree with CB. I would look for an error in setting the angle for the felt wheel. You can also try to use an alternative sw, e.g. TormekCalc2. Good luck.

Jan

Thanks... but I'm thinking Sharpie marker to physically see what is going on... not using another calculator (which can affect consistency...).

For example, Gilles recent post comes to mind... although software was being used to set the angle, different sized wheels resulted in the wheel not contacting where it was doing any good.

I will often mark an edge when I don't get the results I expect (regardless of how I'm sharpening)... it usually quickly tells me what's going on (wrong).
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Offline Hannsi1957

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Re: Rock hard felt wheel
« Reply #4 on: July 09, 2020, 10:26:14 pm »
I’m using a T8 with the standard stone and a half speed 8 inch grinder with 2 ten inch slotted paper wheels. Every time I get a knife really nice and sharp (105-150) on a BESS tester and then get the idea to finish up with a rock hard felt wheel used on the Tormek at slow speed with 1micron diamond spray my edge goes south really bad.  (280) BESS.
So I’m done with that thing forever.  Done finished.
I can bring the numbers back with the paper wheels. Anyone have an idea why the felt wheel dulls the edge? I like to know if possible what happens, even if I’ll never use it again. I’ve tried exact angle and higher and lower.  Btw I use the knife grinders software with angle supports on the paper wheels and the frontal vertical base for the felt.
To add insult to injury the felt polished a “tiger stripe” into the mirror finish which the paper polished back out.



you give up too easily :)
the rockhard felt wheel with a specific weight of 90 (i have seen offers here that are called rock hard but have only 70 specific weight, which is maximum hard) has the excellent property to deburr your knife perfectly. just set 1 degree more grinding angle than you used to grind on japan stone. go over your felt wheel with 1 micron diamond spray (no paste) without pressure 3-4 times in each direction. after each pull, change from front to back. then pull over the leather with your original angle as normal, also 3-4 times in each direction. it is very important to always sharpen in one direction only, never pull back and forth. with a good middle class knife with HRC of approx. 56-58 you will have razor sharp results. My Bess values for such knives are always under 100. even without the use of the paper wheels
cheers Hanns

Offline wootz

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Re: Rock hard felt wheel
« Reply #5 on: July 11, 2020, 04:19:31 am »
German high-density 0.9 g/cm3 felt wheels are made by laying and using adhesives (glue) between the layers - this gives them the abnormally high density.
United Kingdom makes them the same way.

There is a technological limit for natural felt, and high density felt not using any glue can be reached on 1" thick wheels, but this becomes increasingly more difficult with wheels nearing 2" thickness.

Effect of the glued felt on deburring is different from the deburring protocols that we published are for natural felt wheels.
I explain all this and more in the YouTube video https://youtu.be/5iqnvD8_M2k
« Last Edit: November 26, 2020, 01:08:41 am by wootz »

Offline Hannsi1957

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Re: Rock hard felt wheel
« Reply #6 on: July 11, 2020, 07:39:12 am »
That may be Vadim. I'm sure that's reflected in the price. A 3cm thick rockhard here costs a little over 100 € and that is not cheap. But the advantage is obvious. Your cutting edge is not rounded by sinking into the felt. Of course a wider rest is better than a narrow one, but with a little practice you can handle it well, because, as you always say, you shouldn't exert pressure on the felt wheel. And finally I learned everything I know from you. :)

Offline dec11ad

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Re: Rock hard felt wheel
« Reply #7 on: April 17, 2022, 08:26:49 pm »
Where can one source rock hard wheels for a t4 these days?

Offline RickKrung

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Re: Rock hard felt wheel
« Reply #8 on: April 18, 2022, 01:17:43 am »
Where can one source rock hard wheels for a t4 these days?

DuroFelt is one source.

Rick
Quality is like buying oats.  If you want nice, clean, fresh oats, you must pay a fair price. However, if you can be satisfied with oats that have already been through the horse, that comes at a lower price.