knife from 2235 - error prevention

[Indianer]

Alright Guys, this is where we are:

 

I finally got it drawn out to the right length. The handle is still ~2-3mm wider than on the paper, it´s just covered in the pic.

I am unclear about how to proceed and wanted to check back with you on that. My idea is to cut away the excess around the tip with an angle grinder.

I wanted to forge the blade bevels, not grind them. So along the edge I wanted to cut away the excess down to ... 1 or 2 mm over what´s printed on the paper? Leaving the blade a bit wider for now should allow me to grind away any decarburized/oxidized material once the bevels are forged down. Although I don´t even know if that happens in a propane tank forge...?

Then it´d be beating it to banana shape over the concave portion of my RR track anvil and then forging the bevels. EDIT: When creating the banana, I assume I shall not try to hammer down any swelling/bulging/thickening of the material along the cutting edge - just let it grow, then make the bevels and correct thickness issues after, right?

Thanks for ideas, suggestions and warnings. So long, Indi

 

[Frosty]

Are we looking at the paper pattern, where's the blade?

If you have it formed to this shape start grinding the final knife from it.

If you haven't started forging yet, you went to WAY too much work cutting or grinding this out.

When you start drawing the cheeks down, "bevels" the blade WILL curve away from that edge, you'll be working a lot harder to keep it from over curving. That curve is called the "Belly" and you don't form it on edge on the anvil. 

A piece of round stock is MUCH easier to control forging the cheeks than flat stock. 

Frosty The Lucky.

[ThomasPowers]

Decarburization and forging: Some propane forges are really really bad about decarburizing and scaling steel; especially if you can't tune them. I like to run mine a bit on the rich side; but then my shop is very very very well ventilated---rich means more CO output.

However even with a perfect atmosphere in the forge---will you be forging it inside that forge or will you be hammering it on an anvil in an oxygen containing atmosphere? If it's being exposed hot to an oxygen containing atmosphere then scaling and decarb will happen---especially on your first blades!  An experience smith will probably take a lot less time and a lot fewer heats to accomplish the forging of a blade and so have less issues with scaling and decarburization.

[Indianer]

Hello again Frosty - thank you for your answer. I did not realize how misleading that pic was, sorry for that. Let me clear this up real quick:

In the above photograph, I placed a printing of the knife-to-be over the metal bar. I had to draw the bar out to get the right length. I used the paper pattern to check if I got there already. The bar now is as long is the blade should be - it runs below the paper pattern from tip to tang. The tang of the bar is narrower already, I had to draw that section out more.

As of yet, I haven´t done any grinding/ cutting. Does this help?

 

EDIT: Thomas, thx - noted. I like to know what I am dealing with, that´s all. Now I do.

[Indianer]

So, learned a few things...feels like learning to cross a street again. I had severe trouble getting the blade simply straight. Ended up buying a 20 inch aluminum ruler to check during the forging. I am satisfied now.

What I wanted to bring up: When forging the bevels along the belly I worked on near and far edge of the anvil alternatingly, always pointing the belly to the edge and laying the spine on the anvil. I seemed to be unable to create an actual bevel on both sides. Only one side had hammer marks and was slanted, the other remained straight. I finally got both sides slanted towards a midline, doing it the way shown in the pic:

Did I do that very wrong? I mean...it worked after all. Thanks!

[Latticino]

Wrong is a relative term.  If I am reading your drawing correctly you are trying to forge in bevels in a way that is almost diametrically opposed to the way I learned to do it and that I have seen any other smiths use (including some very good bladesmiths).  I typically forge with the edge of the blade on the edge of the anvil (or the shelf with a London pattern) and the rest of the blade resting over it, not hanging in space as you have drawn.  That would be the far edge with full faced blows in your sketch, not the near edge using half faced blows.   I keep the bevel angle of the stock with the spine up slightly, to mimic the bevel I"m putting in on the top side.  Check out Nick Rossi forging on the NESM Youtube channel for a look at someone who does this very well.

[Frosty]

Oh yeah, you're addressing the anvil in reverse for what you wish. Lay the blade lengthways on the anvil with it's edge at the anvil's edge and strike half face blows. The hammer's face extending about half way off the anvil's edge.

A half face blow causes more force to be applied on the anvils edge and so causes more deformation of the stock on the edge. This tips the hammer outwards from the anvil's CL forging a taper to the edge.

How you strike will determine which edge, near or far, is more effective for you. Occasionally I address the anvil from the horn and sight down it's edge to strike precise blows. My left eye is wonky (nerve damage) since the accident so my depth perception and eye hand coordination is off. Sighting the center of the hammer down the anvil's edge is pretty easy, almost reflexive.

Frosty The Lucky.

[Indianer]

10 hours ago, Latticino said:

Check out Nick Rossi forging on the NESM Youtube channel

Done that - you´re right, he makes it easy to see how he strikes. Thx!

I think that´s it - I didn´t use half face blows on the far side of the anvil, rather full faced. That´s probably why I couldn´t taper the blade there. Felt a little wonky as well when I attempted that, half faced blows would have been much more stable in terms of hit and miss.

6 hours ago, Frosty said:

Sighting the center of the hammer down the anvil's edge is pretty easy, almost reflexive. 

I will give it a try when I pass by the smithy next time

[Indianer]

Hello guys. I had to heat it up one last time for changes to correct a minute curve along the axis with two hammer strokes. To prevent new scaling I strew soap scrapings over it. Soap baked on tight, but I don´t think it scaled again...which is good. Used these two heats for normalization then.

Now before I heat treat: I want a portion of the spine serrated and a groove in the front third of the blade. I wish to introduce these with files. Should I do that before or after the heat treating? Could imagine it a source of bending, or the teeth to bend themselves, which would be hard to correct.

Thank you!

[Frosty]

Before or it'll be too hard to file.

Frosty The Lucky.

[Indianer]

On 9/19/2019 at 1:32 AM, Frosty said:

Before or it'll be too hard to file.

Frosty The Lucky.

You were right, was strenuous enough as it is! 

Got a few things going on here. I just noticed that, duh, I made a single-edged blade. I intend to quench in canola oil, vertically. Should I precurve it? All the knifes I see hardened on Youtube are not precurved. They seem to come out as inserted, thus I never thought about this. Then again, for longer things like swords it seems to be a thing regardless of a clay-coat (katanas only)...

EDIT: This is the comment that got me thinking - The author does not distinguish between sword or knife:

"My experience with marquenching low alloy, single edged blades of 5160 and O1 is that they lose appoximately 30% of their curvature quenched edge down or vertically, point first."

[Latticino]

I have never pre-curved a knife blade before quenching in oil, nor seen it done by any of the many knife gurus I've studied with.  The only time I've ever experienced any perceptible curvature in the "saber" direction during a quench is when I clay coated the spine of a very thin blade and quenched horizontally in water (in the classic Japanese style).  That isn't to say I haven't had to deal with warps, but that is a whole different issue.  In my opinion, in the relatively short length and typical cross section a forged knife has it is unlikely to be a problem.  This can certainly change for sword lengths that essentially have a pretty similar thickness, but are several times longer.  This is one of the reasons many sword makers don't grind a single edged sword very much prior to their heat treatment, or allow for sori in some other way.

[Indianer]

Thank you so much! Now I can move on untroubled