How To Radiusing the sides of a ceramic or steel platen

Robert Erickson

Robert Erickson

Knifemaker / Craftsman / Service Provider
Joined
Feb 2, 2014
Messages
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I didn't want to hijack the current carbide platen thread with this question. I may end up going with a carbide platen if it turns out to be feasible, better and cost effective but for now I use ceramic glass.
I'm wondering what is the best way to radius a platen. The edges are straight on my ceramic glass platen which I don't love. I don't think I'd want a huge radius just a little softening of the edge. I like a little radius to the plunge line and it's harder for me to get it symmetrical with the straight edge.
I'd appreciate hearing what you all do to get a good consistent rounded edge. And, for those that have radiused their platens, how much?
 
I made a post in the other thread, but on my steel platens I machined a 1/8" radius on them, and using them is what made me decide to radius my glass platen. I find it preferable because belts of different weight react differently to being hung in empty space, and having that radius behind them has made plunge geometry more predictable for me from heavy weight ceramics through flexible finishing belts.

I rounded the corners on my glass platen with a diamond file like olymon suggested. I started with a 1/16 or so radius but ended up taking it a little further than that. I'm not at an 1/8" radius only because it would take quite a while by hand.
 
Would the black SC belts from Supergrit be able to radius a platen? A 60 grit SC belt for $4 doesn't seem like a huge sacrifice. What about those diamond lapidry disks from amazon?

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The diamond disc would work. The SC belt really won't from what I tried. A cheap diamond disc would be a quick way to do it.
 
SirSpice said:
Would the black SC belts from Supergrit be able to radius a platen? A 60 grit SC belt for $4 doesn't seem like a huge sacrifice. What about those diamond lapidry disks from amazon?

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Click to expand...

Here, those who work with glass use SIC belt to radius the edges of the glass .....
 
I asked the glass guy to have my little slab radioused when i bought the platen...the extra for radiousing was 6$
Be careful, use coolant if you attempt alone
 
I used a 60 grit ceramic belt to radius the edges of my pyroceramic liner. I just took breaks when it started to glow. I was worried this would weaken or break it, but many months later, no issues.
 
Well, I'll give that a try then. Wet maybe. Years of machining has conditioned me that when the work is glowing something is wrong :p
 
I put a radius on one of the platens I got from Nathan. I used my 2x72 and did it freehand. It is close enough to even I cant tell a difference in the sides.

I have been making some knives from 3/32 steel lately and I dont have to move the belt left or right to do the plunge, just keep the belt centered and the jflex belt forms right to it . Thicker steel you would still have to move the belt over

The cubitron belts dont bend much.

Would I do it again ?? Yep But there are also times when I want a square edge on it so 2 platens live in my shop
 
For glass or ceramic stezann has the right solution. The business that can cut the glass will have the right tools to do the radius work quickly and safely. When you grind glass or ceramic you create free silica which is quite hazardous to breathe. You can do the work safely if you keep the dust wet, but cleaning up completely so there's no leftover dust to dry out and float around the shop is the trick...
 
Your grinding belts produce similar dust as they fracture when you grind. G10 is just as bad.

Everything we do is hazardous. I would hope that if someone is making knives, they've got a respirator on that protects them from stuff like this... that's not to say the idea of the shop that cut it doing it is a bad idea, btw. Quite the contrary!! It's just that we already contend with stuff like this. Doing it smart is up to the operator.:thumbsup:



Mahoney said:
For glass or ceramic stezann has the right solution. The business that can cut the glass will have the right tools to do the radius work quickly and safely. When you grind glass or ceramic you create free silica which is quite hazardous to breathe. You can do the work safely if you keep the dust wet, but cleaning up completely so there's no leftover dust to dry out and float around the shop is the trick...
Click to expand...
 
Matthew Gregory said:
Your grinding belts produce similar dust as they fracture when you grind. G10 is just as bad.

Everything we do is hazardous. I would hope that if someone is making knives, they've got a respirator on that protects them from stuff like this... that's not to say the idea of the shop that cut it doing it is a bad idea, btw. Quite the contrary!! It's just that we already contend with stuff like this. Doing it smart is up to the operator.:thumbsup:
Click to expand...
AO belts get dull , but ceramic belts are self sharpening which mean that they produce fine dust . Why I think that exactly that dust is what EAT platen ? Not friction of clean belt with plate ? Most likely they stuck in the fabric and we have double sided grinding belt :D There MUST be difference in how long will last plate if someone use only AO belts with someone who use most ceramic belts? And if all this is true maybe it is possible to take that dust away from plate ?
 
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