felt on platten, grind angles

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Starchaser426

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Jun 8, 2013
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I've searched for .25 or thicker felt to attach to my 2" platten, to no avail. I've tried hobby stores, and fabric stores. I can only find it about tagboard thick. Is this thick enough, can I somehow double/or more thicknesses somehow? I've found a "batting" for oven mitts, hot pads, but am unsure of its' suitability. Any thoughts?
Also, what angles are favorable for flat grinding with a convex mico bevel? How about kitchen knives, beveled both sides? Is 52100 suitable? What do you prefer?
This Noob thanks you in advance for sharing your knowledge and experience.
Regards, Mark
 
Normally one would consider putting a hardened ceramic backing on a platten rather than something soft. I can't visualize how felt, regardless of how thick, would hold up to thousands of feet of sanding belt running over it. What is the purpose of putting felt on the patten?

I can't speak to your other questions.

- Paul Meske
 
My pal Raymond Richards sent me a couple of pieces of some kind of 1/2" thick industrial felt a few years ago. I glued (3-M #77) it to my platen and gave it a try.

It smells like a wet dog after a bit, but gives the ability to do a somewhat "convex" grind without using the slack-belt method or a rotary platen.

It works pretty well, but isn't long-lasting, and is easier to achieve a smoother finish on your blades with the grinder (cushioning effect).

Since the majority of my blades are flat-ground, I haven't used it in several years.

Robert
 
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Mike Stewart (of Bark River fame and a strong proponent of convex grinds) once suggested PVC foam on the platen to get a convex grind.
 
If you're really set on it, the hardware store should have some furniture sliders that come in at .18" thick. Self adhesive too!
 
Thanks for the quick initial responses. I've done some flat grinding and some slack belt grinding already. I'm looking for a couple of alternatives and better ways to do things. The ceramic platen attachment is in my near future. As far as the grind angles, I recall seeing, some time ago, and I don't remember where, a chart with angle/width of bevel, and perhaps other info on it. The Japanese Nakiri vegetable knife, and the Chinese cleaver intrigue me. I was able to obtain a Japanese made Chinese cleaver at a thrift store for about $1.00 and have been impressed with its' kitchen usefulness. It has a hollow ground blade, which is a negative mark, imo, and would like make my own interpretation of one. Hence the questions concerning 52100. Speaking of which, I've seen Youtube videos of people heating and quenching it 3 times. Is this treatment adequate? I'm skeptical, but have never used it. I've been experimenting with 1075, but we all know how it likes to corrode.
 
What kind of equipment do you have to HT 52100 properly? It takes a soak time at a controlled temp to get the most from it. A triple quench is never necessary in my opinion if the blade is properly normalized prior to the final HT. You can use a quench in the normalization though. 52100 only has 2% chrome and is not that big of step up in the anti corrosion ladder over 1075. Many very high end kitchen knives have been made from plain high carbon steels for years. The famous Japanese white and blue paper steels that have a great rep in the kitchen knife community are high carbon with no chrome. The secret is how is the knife cared for. For a cleaver type blade I would buy into a convex grind because it is more of a chopper and the extra metal behind the edge would help support it. On a slicer for things like veggies I would want flat or a small hollow. There I want the edge to cut and the rest of the blade to follow it without pushing the material away any more than necessary. I am not a big kitchen knife guy, but, I don't think I have ever seen one with any kind of a convex. Good Luck what ever you do.
 
I've seen leather glued to platens for cushioned grinding, seemed to work OK. I make kitchen knives, and use very slightly convex grinds often. It was described to me once as "convexity that you have to look for to detect." Basically, to me that's a full flat grind taken to .040 at the edge, heat treated, and then the bottom third of the blade ground slightly convex until the edge is at .010-.005" before sharpening.

Thinness makes for good slicing, and fully flat ground blades achieve this very well, but there is a property called "food release" that kitchen knife connoisseurs like a knife to have, as well. If you cut a potato or zuke up, and have chunks of it sticking to the blade and getting in the way, it can be irritating and even slow you down. The little scallops known as "grantons" that are found ground into the sides of some chef knives and santokus are an attempt to reduce this, but mostly ineffective. A better way is this slight convexity. The idea is that its curve breaks the suction of food slices being cut. I've never used a knife where no food at all stuck to the blade though...

I don't use a soft platen at all, just full flat grind, then round it out with many light side to side and rolling passes. Many times I finish rough grind and finish grind the edge with the blade held vertically on the platen, giving evenness and good blending ability. I hand sand everything, so this also helps me to blend, but I can get a good belt finish on convex grinds too, with Gator belts and a slight rolling of the blade when finish grinding it. Scotchbrite belts can help here, too.

That's my $.02 as it applies to convex kitchen grinds, anyway. Good luck to you.
 
I've seen Youtube videos of people heating and quenching it 3 times. Is this treatment adequate?
Click to expand...

Thought I'd address that real quick too. There is so much more to blade heat treatment than just "heating and quenching." Especially with more complex steels like 52100. I will say that with the right care taken, a triple quench is a very good way to treat 52100 for blades, but that it's not necessarily the best way, and that even the implication that there is a "best way" would be misleading. 52100 is a great example in fact, of a steel over which some actual controversy exists concerning heat treatment for knives.

You've got a lot of reading to do! Use the search function for instance, if you want to form your own well educated opinion about 52100. I'd stick to 1070 right now though, there's nothing wrong with it at all.
 
Hi All, I think this is my first post here,
you can find a good range of felts on McMaster.com. (1ft square for ~$15) my favorite place for hard to find shop supplies.
I was just looking around for how people make their felt faced platens. I've been learning from a guy who never takes it off his second grinder.
good for finishing not really any point for hogging out.
It is very nice to grind on, especially if your grinder is home made and/or has a little vibration to it.
I would start with firm grey. This is a guess since I've not made myself one yet.
 
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