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Fix the warp or not?


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Hello everybody

 

I've got a situation that I'm not sure how to fix, or if I should really try to fix at all. I'm an amateur with all this, and I just finished the heat treatment on my first real knife, and I plan on selling this one (or another one just like it). It's made out of a file, worked at above critical except for the last few heats. I ground and stamped it before normalizing three times, though I'm not sure I got it hot enough during this stage. I tried to quench it in used motor oil (I know... I know...) but I got away with myself and took it out before it reached critical. No surprise here: it didn't harden. I put it back in, brought it slowly to critical, and quenched in room temp water. It hardened this time. I cleaned it up a little and tempered it on a block of red hot steel to a dark straw going into brown. It's ready to be sharpened, but it was at this point that I noticed it was warped.

 

So, my question is, can I get away with heating it up, forging it flat, re-normalizing a couple times at critical, followed by a quench at critical in oil and re-tempering? Will it just warp again? Could I straighten it without re-heating? Should I leave it as is? Would anyone buy it as is (in other words, is it sell-able once it has a handle and sheath)?

 

Let me know what you think, here are links to pictures of the blade.

 

Side

 

Other side

 

The edge

 

The spine

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Hello everybody

 

I've got a situation that I'm not sure how to fix, or if I should really try to fix at all. I'm an amateur with all this, and I just finished the heat treatment on my first real knife, and I plan on selling this one (or another one just like it). It's made out of a file, worked at above critical except for the last few heats. I ground and stamped it before normalizing three times, though I'm not sure I got it hot enough during this stage. I tried to quench it in used motor oil (I know... I know...) but I got away with myself and took it out before it reached critical. No surprise here: it didn't harden. I put it back in, brought it slowly to critical, and quenched in room temp water. It hardened this time. I cleaned it up a little and tempered it on a block of red hot steel to a dark straw going into brown. It's ready to be sharpened, but it was at this point that I noticed it was warped.

 

So, my question is, can I get away with heating it up, forging it flat, re-normalizing a couple times at critical, followed by a quench at critical in oil and re-tempering? Will it just warp again? Could I straighten it without re-heating? Should I leave it as is? Would anyone buy it as is (in other words, is it sell-able once it has a handle and sheath)?

 

Let me know what you think, here are links to pictures of the blade.

 

Side

 

Other side

 

The edge

 

The spine

 

 

See if you can stone it out on a flat water stone NOT OIL this will thin the blade out on the heel and tip but bring it out flat , but the ammount of warp i can see in the pic.s i would say go ahead and finnish it , its not that bad then sell it i have seen worse in very expensive Japanese swords and tanto

 

hope this helps you. tell

Edited by tell

Terence.........(today started off perfect now --- watch sombody come and stuff it up ]

 

if it aint broke dont fix it

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See if you can stone it out on a flat water stone NOT OIL this will thin the blade out on the heel and tip but bring it out flat , but the ammount of warp i can see in the pic.s i would say go ahead and finnish it , its not that bad then sell it i have seen worse in very expensive Japanese swords and tanto

 

hope this helps you. tell

So you're talking about taking metal off with the stone on the top of the arch so to speak? I'm not sure I want to do that since it's the thickness I wanted. I think I'd rather leave it be than go that route.

 

So it's sell-able? What would a knife like this go for? (That's with a stacked birch bark and silver or brass handle and a veg tan leather sheath)

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If that happened to one of mine, I'd heat it to the temperature I want to temper it at, then just use a very small hammer to beat it back into shape. The warp is one single arch, or so it looks, so it could be easily done. However, I'm not sure if file steel will behave similarly to 1080 or 1095, which are the two I work with, so I'd recommend doing some research on the steel to prevent any bad surprises.

 

If the edge is warped more than once (i.e. wavy as opposed to a single arch) you could grind it down, similar to what Tell mentioned. I've never used stones in that way before, though. I usually either sand or file after a heat treat on a thin blade.

 

Oh, and about the price: I'd pick a flat wage for your hourly work, factor in materials (don't forget disposables such as grinding belts, fuel, etc.), then see what the price comes to. The price also depends on whether you have a buyer already (commission) or if it's going to be sold online or something. When I sell something online, I set the price on the high side then drop the price every so often, but never below what I want it to sell for.

 

 

Hope that helps!

 

-Dan

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If that happened to one of mine, I'd heat it to the temperature I want to temper it at, then just use a very small hammer to beat it back into shape.

 

Hope that helps!

 

-Dan

 

Ok, so bring it back to the temper color, and use a light hammer to straighten it. Sounds good. One question though, will bringing it back up to that heat make it lose too much hardness?

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hi there ..

i think this is something of a more personal question.

 

would it sell?

yes, im sure it would .. for every blade has a buyer.

 

can you reforge it straight and re heat treat it?

im sure you can.

if you quench in water, you have a chance of ending back here with a warp ..

especially if you do not heat the blade evenly .. or if you dont quench the blade straight into your quenching medium etc etc ..

 

you could try straightening it cold ... but you do run the risk of cracking the blade.

this would depend on what steel you have used and how it has been treated.

there is always a risk.

 

but all in all .. you mention that this is your first blade ..

sometimes these things happen and we just need to treat them as learning experiences.

and most of the time when something like this comes up .. i Personally try to remind myself that the attention to detail and the level of my work are all reasons as to why people would want to come and purchase a blade from me rather than going to a department store and purchasing a knife there.

 

so, i thats why i say it might be more of a personal question.

 

i certainly didnt sell most of my early blades.

:)

 

just an opinion.

deeDWF4.jpg

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hi there ..

i think this is something of a more personal question.

 

would it sell?

yes, im sure it would .. for every blade has a buyer.

 

can you reforge it straight and re heat treat it?

im sure you can.

if you quench in water, you have a chance of ending back here with a warp ..

especially if you do not heat the blade evenly .. or if you dont quench the blade straight into your quenching medium etc etc ..

 

you could try straightening it cold ... but you do run the risk of cracking the blade.

this would depend on what steel you have used and how it has been treated.

there is always a risk.

 

but all in all .. you mention that this is your first blade ..

sometimes these things happen and we just need to treat them as learning experiences.

and most of the time when something like this comes up .. i Personally try to remind myself that the attention to detail and the level of my work are all reasons as to why people would want to come and purchase a blade from me rather than going to a department store and purchasing a knife there.

 

so, i thats why i say it might be more of a personal question.

 

i certainly didnt sell most of my early blades.

:)

 

just an opinion.

Thanks Dee!

 

I've already realized this knife has several mistakes, and I'm probably going to end up hanging onto this one (And if I'm keeping it, I want that warp out for sure!). But I do want to make and sell another similar one, if for nothing else to pay for making more knives! :D Thanks for your input!

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That's a good looking blade. Personally, I use a bending fork in my hardy hole to straighten blades. You could possibly get by with taking it up to tempering temperature and straightening it but I can't guarantee that that won't snap it. I usually just end up reheating it until it's a dull red and then straighten the blade. I didn't have a good eye for straightness at first so I used a straight edge to check for warping. When you are satisfied with the straightness normalize it a couple of times. Turn your forge down so that you don't overheat the blade and make sure that it reaches non-magnetic, let it soak for about a minute and then let it air cool. Moving the blade around in the forge a bit helps reduce hot spots. Then re-austinize and soak it again and move quickly to the quenchant and stick the blade straight into the tank whether you full or edge quench. Some recommend agitation or an interupted quench but I just get the blade into the quenchant staight and hold it still until it's had enough time to come down to the temperature of the oil, or whatever you're using. Learning to straighten blades is just part of the process.

 

Doug Lester

HELP...I'm a twenty year old trapped in the body of an old man!!!

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Ok my first question is, is the entire blade hardened? Or is the edge only hardened?, but anyway, if the whole thing is, remove the treatment and fix the warp and try again.

Edited by WmHorus

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just use common sense.......dude your boned

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That's a good looking blade. Personally, I use a bending fork in my hardy hole to straighten blades. You could possibly get by with taking it up to tempering temperature and straightening it but I can't guarantee that that won't snap it. I usually just end up reheating it until it's a dull red and then straighten the blade. I didn't have a good eye for straightness at first so I used a straight edge to check for warping. When you are satisfied with the straightness normalize it a couple of times. Turn your forge down so that you don't overheat the blade and make sure that it reaches non-magnetic, let it soak for about a minute and then let it air cool. Moving the blade around in the forge a bit helps reduce hot spots. Then re-austinize and soak it again and move quickly to the quenchant and stick the blade straight into the tank whether you full or edge quench. Some recommend agitation or an interupted quench but I just get the blade into the quenchant staight and hold it still until it's had enough time to come down to the temperature of the oil, or whatever you're using. Learning to straighten blades is just part of the process.

 

Doug Lester

 

 

Ok my first question is, is the entire blade hardened? Or is the edge only hardened?, but anyway, if the whole thing is, remove the treatment and fix the warp and try again.

Doug, thanks for the forge along, and for the compliment! Very helpful, and probably better to retry the whole heat treatment than to break an otherwise decent blade.

 

Horus, The whole blade was hardened, but the back and sides were placed directly on the heat source during tempering, so they are probably a little softer than the edge is. Regardless, I guess it's for the best to retry the heat treatment.

 

 

Thanks to everybody who helped out on this topic. You all helped me out tremendously in figuring out where to go from here, and you did it in so little time! I'm going to try to re-normalize a max of 2 more times, and re-quench it in oil. I'll be ready this time!

Edited by Myles Mulkey
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to me it looks like you could take the warp out over your knee, or by sticking the point into a bench and using the heel of your hand. that said, if this was forged, and you're not sure of your normslising temps, then don't sell. try again. if you haven't refined the grain, it will break in use, and you'll never sell another knife. steel is cheap - know what you're doing before you trust someone else's life to your work.

 

that said. the shaping is gorgeous. finish and use it for yourself. see if the edge bends or chips out, if it does what you want from a knife like this, if it works, and then if it breaks, post a pic of the grain size, so we know what you've done wrong.

Jake Cleland - Skye Knives

www.knifemaker.co.uk

"We can't solve problems by using the same kind of thinking we used when we created them."

"Everything should be made as simple as possible, but not simpler."

"Two things are infinite: the universe and human stupidity; and I'm not sure about the the universe."

 

Albert Einstein

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I have two comments. I can see from the second picture what looks like alligatoring (a spotty surface like 'gator skin). This tells me that you were 200-300 degrees too hot when you quenched, and likely your normalizing temps are high as well. This can contribute to warping. If you are HT'ing by eye and color, a dark shop helps, even a magnet can fool you, you want the lowest temperature were the piece looses magnetivity.

 

Second, you should consider the fact that every piece you send out of the shop is representing you and your work to people you have never even met. Is this piece (which ever one "this" one is) one that you want other people to judge your skills by?

 

I would re-heat and take the bend out, re-normalize at least once, and re-HT in oil. Make sure that you don't wave the piece side to side as it cools, that is a sure way to warp a blade. If you must move it, straight up and down is what you are after.

 

 

As the Master said to Kwai Chang Kane "sometimes you lose".

 

Geoff

"The worst day smithing is better than the best day working for someone else."

 

I said that.

 

If a thing is worth doing, it is worth doing badly.

- - -G. K. Chesterton

 

So, just for the record: the fact that it does work still should not be taken as definitive proof that you are not crazy.

 

Grant Sarver

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Ok, so bring it back to the temper color, and use a light hammer to straighten it. Sounds good. One question though, will bringing it back up to that heat make it lose too much hardness?

 

 

I know you've already found a solution, but just to answer your question: If you temper right up to the temperature you reached before, you shouldn't lose hardness. If anything, you'll just make the tempering more thorough. Just don't go above the previous temperature. I've done such a thing probably 4 times max, and had no ill effects, but I can't vouch for what will happen if you repeat that process continually, though I'd be interested to experiment...

 

-Dan

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Myles

your blade looks good so far except for the bend.... If you would not want to own this blade with a bend why would you SELL it to someone ? That is an excellent way to gain a reputation...If you had it on a table and someone was willing to buy it with the bend after they had seen it , well then buyer be ware I suppose and everyone the buyer shows the blade to will remind him that he bought a bent blade... that kind of a reputation won't bring new people to your table..If you were to send it to someone after they sent you money they would be within bounds to ask you to replace it or give them their money back... If you are not proud of it enough to keep yourself you shouldn't even consider selling it....

Like has been mentioned above don't send out anything that will earn you a bad reputation.... First impressions and all eh?

Go Back and straighten, it is good practice and YOU will be satisfied first and foremost...

Dick

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Myles

your blade looks good so far except for the bend.... If you would not want to own this blade with a bend why would you SELL it to someone ? That is an excellent way to gain a reputation...If you had it on a table and someone was willing to buy it with the bend after they had seen it , well then buyer be ware I suppose and everyone the buyer shows the blade to will remind him that he bought a bent blade... that kind of a reputation won't bring new people to your table..If you were to send it to someone after they sent you money they would be within bounds to ask you to replace it or give them their money back... If you are not proud of it enough to keep yourself you shouldn't even consider selling it....

Like has been mentioned above don't send out anything that will earn you a bad reputation.... First impressions and all eh?

Go Back and straighten, it is good practice and YOU will be satisfied first and foremost...

Dick

I hear you. It was a bad question anyway, and it was meant to see how bad you guys thought the warp was NOT that I was planning on passing it off to somebody and screwing them over (even if that's what it sounds like). I'm going to completely retry the heat treatment, keep it, and make another similar knife later for sale. The fact is, I'm a college student and don't have much spare cash at all to fuel my smithing hobby. I thought I could use some of the resources I already had, make something worthwhile, sell it, and keep going from there. Thanks for your input, and for trying to save me from myself! :o

And Dick, I was very hurt for a second after reading your post, because I forgot that Dick was short for Richard. I thought I must have made you really mad! :lol:

 

Again, thanks to everybody for helping out. I'll post pics of the result.

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we have all been there :)

dont worry.. it wasnt a stupid question.

and anything you learn from is supposedly a success

^_^

(just dont remind me of that theory when im having a bad day in the workshop ;) )

 

oh .. and i think i can say with fairly certain assurance that you dont have to worry about being called silly names around here.

:)

tis all about the learning in these parts.

all on the same side, afterall.

-_-

 

ill look forward to your next blade.

deeDWF4.jpg

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we have all been there :)

dont worry.. it wasnt a stupid question.

and anything you learn from is supposedly a success

^_^

(just dont remind me of that theory when im having a bad day in the workshop ;) )

 

oh .. and i think i can say with fairly certain assurance that you dont have to worry about being called silly names around here.

:)

tis all about the learning in these parts.

all on the same side, afterall.

-_-

 

ill look forward to your next blade.

Thanks Dee! I hope I don't let you down, haha :D

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In the end your going to need to know how to straighten out blades. As far as I know everyone I have worked with uses pressure not impact to straighten blades. You can do it in a vise with two pieces of wood on one side and one on the other or you can do it Asian style by using two long handles with blade slots. Just be careful while you figure it out, wear safety glasses in case you have a snap.

 

I fixed a knife the other day by sliding it in between the walls of a log cabin, then adding a bit of pressure by pulling it down, worked great.

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I've a damascus blade I did that was to the point I was gonna give it one last chance before tossing it.

it'd curved pretty good first quench, and still a bit in the second, I should have left it beefier when doign the first grind.

 

I don't think I'll sell it as it has a small flaw at the heel of the edge, but it'll be sent to kitchen duty, I don't see a reason to waste it =P

 

Anyway on my last heat treat attempt it still had a bit of curve, so I have a bench vise with a flat area on the back, that's sort of a small anvil. Laid it on it and just gave it a few good smacks with a blade (this was after tempering). Trying to flex the blade straight, it just wouldn't take a set, just was bendy.

 

but smacking it set it straight, so we'll see how it holds up and if it did any damage once I throw a handle on it.

Beau Erwin

www.ErwinKnives.com

Custom knives

Bcarta Composites

Stabilized Woods

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