Thread: First edges -difficult for you?

Once again, Charlie, thanks for your advice.

Does this mean that you take the side of the blade (like the wedge surface) to the belt grinder to set the bevel, and then grind out the hollow? That could certainly speed things up, but could be a bit finicky to hold just right. Will try it out.

I had ground the edge to within say 1/64 while grinding the hollows but then on the diamond hone I had to sweat through a lot of steel at the spine and bevel on the way to a cutting edge.

I'll experiment some.

If you got carbide banding the steel wouldnt really harden...and that would explain the burr easily. but that requires disasterous overheating during forging and or heat treat... on hypefreeblades there is a thread on carbide banding... with images...

If you get to the blue or brown range with heat treat, the steel will be more brittle relative to the hardness you get... its called the blue brittle zone... it is not very dramatic, so it is just that you dont gain much toughness for the loss in hardness... this occurs above 400f. It may explain at 15deg the burr and difficulty sharpening... it is not THAT noticable in thick and less acute edges...

Do you normalise after forging? At what temps do you austenitize and do the rest of the treatment... "matherton forge" has some very nice and basic 01 heat treatment advice... and others... for blade smiths.

Is your forge set up to burn rich?

I was forging at bright orange, stopping at dull red, and not likely getting up into the yellows, but I am still pretty new to forging and had new green lenses on.

I left the work in my forge and closed the doors and let it cool as slowly as possible, but I'm not sure if it normalized properly.

For heat treat, I heated to orange and then quenched in warmed canola oil.

For tempering I used the kitchen oven set at 400*F for two hours and likely overshot a bit again. My best results have come from heat treating on a hard fire brick in that oven; I'll have to go back to that, I think.

The banding looks cool but doesn't help much!

And thanks for the feedback and resources!

O1 is actually quite a complex steel to heat treat optimally...my own efforts in it was met with mixed success, as O1 is very sensitive to overheating. I also see orange the moment the shadows disapear and it stays that way for me... even though the digital camera might graduate the colours and even show some yellow...

The best results were when i just barely saw the shadows disapear then quenched it. This is not optimal from a carbon solution point of view, but it avoids overheating and grain growth... If i left it to become orange as i see it, it overheated and made large grains...

But in practice i am a noob in ht... higly read, but still a noob in practice so take what i am saying with a pinch of salt.

1084 or 1080+ or 1075 is probably a safer bet with the tools you have.

P.s. i dont go higher than 350deg on the kitchen oven and only for 30mim twice and i quench in water between heats... we are dealing with thin sections... they dont need two hour tempering cycles...

Forgot about the atmosphere. I can make my forge billow yellow flames but even at its leanest, I always have flame coming out, which heats the forge body, so I don't overdo the fuel-rich mix for any longer than necessary.

I'll shorten the kitchen science experiments as well!

It is fun... i am envious of the forge you have... but first i want an oven...

Originally Posted by spazola

A) set the bevel as part of the grinding process

I used to do this, but these days only for razors that need etching, because I don't want to risk having to re-etch.

Originally Posted by spazola

B) leave enough metal width wise so that I can grind away the width of the blade a little bit.

Charlie

Yes. After HT I touch the edge full on to the grinder. It gets rid of the decarb layer, as well as make the edge shiny so it is easier to judge thickness during grinding. And during grinding I grind until the edge just about starts to foil. This can be slightly risky, but has the advantage that the geometry of the blade will be correct, the bevel will be very small and even, and honing becomes easy.

Originally Posted by Bruno

Yes. After HT I touch the edge full on to the grinder. It gets rid of the decarb layer, as well as make the edge shiny so it is easier to judge thickness during grinding. And during grinding I grind until the edge just about starts to foil. This can be slightly risky, but has the advantage that the geometry of the blade will be correct, the bevel will be very small and even, and honing becomes easy.

Yes, sometimes i will grind down to a thin edge .003 or so. There are lots of ways to skin a cat.

Charlie