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I Forge Iron

drawknife in progress


bobasaurus

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few questions.. Are you working by pattern or drawing?   Are you copying or recreating and existing one? 

 

A few minutes at the forge  can take hours off of grinding.. 

 

What are the final plans as to how it will be used..  Reason I'm asking is this determines how the edge both in thickness, shape and handles are decided.. 

 

Looking forwards to the finished product.. 

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Thanks stockmaker, never forged one of these before.  There are a few problems, but it came out okay.  After some grinding it will be a decent tool.  

1 minute ago, jlpservicesinc said:

few questions.. Are you working by pattern or drawing?   Are you copying or recreating and existing one? 

 

A few minutes at the forge  can take hours off of grinding.. 

 

What are the final plans as to how it will be used..  Reason I'm asking is this determines how the edge both in thickness, shape and handles are decided.. 

 

Looking forwards to the finished product.. 

Basically just winging it, though I have two commercial drawknifes I looked at beforehand as a rough reference.  I splayed out the handles on this one to give more clearance, as the blade is pretty small.  The blade curved when forging in the bevel, so I left it.  I'm going to grind a flat on one side and a bevel on the other, and use it for all kinds of smaller woodworking tasks.  The handles are angled more for bevel-down use than bevel-up.  

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You can avoid the curve if you want. It is possible to hit on the side that is going to become the edge to straighten it. Do this as soon as you see it bend.  It will not become very much blunter in the process and the little that you get disappears in the next heat. This of course means that you must have an anvil with some length. A sledghammer head is too small.

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11 minutes ago, gote said:

You can avoid the curve if you want. It is possible to hit on the side that is going to become the edge to straighten it. Do this as soon as you see it bend.  It will not become very much blunter in the process and the little that you get disappears in the next heat. This of course means that you must have an anvil with some length. A sledghammer head is too small.

I find a pre bend works very well also.. Bend it the opposite way of what you think it will need before forming of the edge..  Then form the edge.. this will curve it back and eliminate the straightening and save hitting the cutting edge against it.. 

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23 hours ago, stockmaker said:

Thanks for posting.  Forging a draw knife is on my list of things to-do, if possible keep the progress pictures coming.  The transition between handles and blade is nice, have you done many of these?

Draw knife is on my list too, I bought a couple of Axe Heads that need handles made.

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I'm not sure what kind of handle you intend, but I usually like to forge tapered tangs long enough to extend through the handles and be riveted.  Blind tangs with a few barbs to prevent backing out work pretty well too.  IMO you have done right to orient your handles for working bevel down... I find that to be much more versatile for most of my work... where needed I don't hesitate to flip the knife though.  

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3 hours ago, bigfootnampa said:

I'm not sure what kind of handle you intend, but I usually like to forge tapered tangs long enough to extend through the handles and be riveted.  Blind tangs with a few barbs to prevent backing out work pretty well too.  IMO you have done right to orient your handles for working bevel down... I find that to be much more versatile for most of my work... where needed I don't hesitate to flip the knife though.  

When you say riveted, are you inserting a rivet through both the handle and tang like a knife, or are you treating the tang like a large rivet and peening the end?  I'm not sure what to do for the handles yet, honestly.  I have a wood lathe, so I can turn them.  Attaching will be tricky.  

14 hours ago, ausfire said:

And what stock did you use? Looks a bit like a shaft from a gas lift or light hydraulic ram??  A bit long though.

I started with 1/2" diameter O1 drill rod.  

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Did you make that drawknife?  It looks very clean compared to mine.  

If I had thought to forge shoulders into the handles then peening would work great... not sure what would keep the handles from riding up with my current forging.  Maybe I'll try to get a tight fit and glue, then peen or thread on caps of some kind.  Peening might be hard, since I made the whole thing from O1 and heat treated it all.  I softened the handles with a torch some, we'll see if it was enough.  

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9 hours ago, bobasaurus said:

Did you make that drawknife?  It looks very clean compared to mine.  

If I had thought to forge shoulders into the handles then peening would work great... not sure what would keep the handles from riding up with my current forging.  Maybe I'll try to get a tight fit and glue, then peen or thread on caps of some kind.  Peening might be hard, since I made the whole thing from O1 and heat treated it all.  I softened the handles with a torch some, we'll see if it was enough.  

Yes. This was made in the blacksmith demo trailer doing demos at a show..  5160 blade, pear wood handles.. forge welded ferrules.. Water quench.

all hand made, no drills, grinders or the like..  Just files, and sand paper.. 

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13 minutes ago, Peter Bui said:

When using a draw knife is it more of pulling motion or pushing motion?

 

is 5160 ok for a drawknife/sen? I've always wanted to use one instead of the linisher/grinder. 

Cheers

It's a pulling motion, you draw it towards yourself while the piece is clamped in front of you.  You can use it whatever way works, though.  Sometimes you have to reverse direction on cranky wood grain.  Never used 5160, but I suspect it might not have super edge retention from the somewhat low carbon content.  If you're using it more for bark removal, it wouldn't matter.  

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4 hours ago, Peter Bui said:

Ok thanks. 

Wanted a drawknife/sen for rough filing work.

Thanks

5160 gets plenty hard to act as a Sen..  58Rc-62Rc in the hardened untempered state..   In today's Metallurgy and alloying fields there are so many different steels that are designed (designer) to work better in some situations than others but for the most part O1, W1 or W2, or A1, 4140, 4150. 5160 can be used to good advantage in many different roles as long as the heat treat is appropriate for the job at hand.. 

As a simple demonstration.. S7 is said to make great hot chisels, punches etc, etc, So does H13,, But so does 5160, 4140, 4150, O1.. I have hot and cold chisels and punches with many thousands of hits, hole, cuts, slots etc,etc on them and they will have many, many more before their life is consumed..  Anyhow, the argument comes down to semantics and which someone prefers.. If you are an engineer and have to have exactly the right material then 5160 is probably not your choice..  I would have no problem using it..  

Traditional Japanese Sens are made with a low high carbon (0.07-0.85) cutting edge laminated to a softer core..  These steels are considered water hardening steels. 

A draw knife and a Sen are 2 totally different tools and are designed for the materials they are used with..

 

A draw knife is used on wood  and usually drawn to a peacock or purple which lends itself for the ability to hold a good edge but also be sharpened with a stone or a file..  Has a very thin edge profile with very little back up geometry as the edge has plenty

A Sen is left fully hardened or a light bronze Temper and is used on Normalized, annealed on surfaces of which the Rc is at it's lowest point..  

One could argue the best steel would be a HSS until you look at the forces involved and even with a blue temper on the HSS (depending) it would make a bad Sen.  

Anyhow the argument as to which steel makes the best what ever will never die since everybody has an opinion and the argument of Engineer vs shop floor person doing the work is always an issue.. 

I've made draw knives and Sens out of the same materials from 5160  to 50100, W1 etc, etc.. How you heat treat it will have the largest effect on its use.. 

Anyhow, 5160 would work great as long as you understand the edge geometry and how to create the geometry needed to support the cutting action you want.. this might take some experimenting and the limitations a Sen has in stock removal.. It's great for removing high spots or planing a not to wide blade but once you get to a certain width the amount of strength you would need to make it works becomes astronomical.. I find a sharp file can strip metal pretty fast with less dangers of gouging involved both to the work piece and to myself.  

 

Enjoy..  

 

 

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3 minutes ago, rockstar.esq said:

jlpservices,  That was a very informative post!  Thanks.

 

I thought I'd mention that a drawknife often has a slight bevel on the "flat" side so you can finely control the depth of cut.  That slight modification can make the tool capable of much finer work.

Mine has a slight convex curvature on the flat back towards the edge, letting me rock it a bit to control the cut on the flat.  This was less intentional than from my inability to grind a perfect flat without convexing it a bit.  

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I find that the old draw knives have a blade design not unlike a razor. The stiff, solid back (most are soft, as many old ones that have been abused are mushroomed) a fuller just infront and then the edge bevel. Often if you lay the stone against the back, and use it as angle gauge (like you do a razor) you can get that nice edge you need on it.  

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I prefer mine to be perfectly flat on the back side.. This allows for me to take off just the right amount at a high spot and by running the knife flat I can burnish the wood at the same time..   If I need to take more just change the angle of the draw knife to what ever depth of cut I want.. 

 

In the olden days where everything was done by hand.. They had like 1000's of different kinds of draw knives.. Concave, convex, Round, sweeped. Short, long, wide, narrow.. pivoting handles, blades swept forwards, blades swept backwards.. 

Each had a particular task which it was designed for or more in mind but could also be used for other things..  Some of the concave bladed ones are also designed to be used upside down.. 

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