All my knives are breaking!

[Tanner]

I just started and don't understand. I get to where I'm almond at done with my blade and I'm just doing dome finishing, I hit it while it's hot and it breaks in half. What am I doing wrong?

[LastRonin]

Right now... not giving the experts who might be able to help enough info... e.g. what steel, what kind of forge, what color heat you are considering hot, did you cool it with anything between heats.... etcetera

[ThomasPowers]

Depending on the alloy you may be hitting it too hot.

Depending on the alloy you may be hitting it too cold.

not telling us the temperature and the alloy gets answers like this.

[Tanner]

I used a drill bit and a rat tail file. I got it pretty hot, like almost yellow heat and I cooled it in sand and water. Should I have annealed it again?

[Steve Sells]

sand AND water??????

[ThomasPowers]

If the drill bit was high speed steel it can "cottage cheese" if over heated; also  What do you mean by "cooled it in sand and water"  A high carbon steel can shatter if quenched in water.  

What blacksmithing books have you checked out of the local public library and read?.

[Dogsoldat]

Better have a good read though the heat treat stickies in the knife section.  then read them again...   depends a little on steel but yellow is going to be on the hot side and then being put in wet sand?  will harden the steel.  depending on what steel is being used this may be a too aggressive cooling.  best get back to basics and read everything you can for a while.  then it will all make a little more sense. 

[Frosty]

In part you're trying to teach yourself blacksmithing by forging knives. This isn't a recipe for success. Drill bits aren't beginner level bladestock by a long shot.

Iforge has a pretty extensive bladesmithing section including I don't know how many hundreds of pages in the heat treat sub section.

For instance, cooling the stock in sand AND WATER is a HUGE mistake, virtually guaranteeing failure. Even if it were a water quench steel the sand would prevent the water from circulating creating hot spots on the blade, it'd come out really stressed.

It's good to build a fire and beat steel but you need to know more about the material before attempting blades. Don't give up, just take the right steps in the trip. We'll help.

Frosty The Lucky.

[Tanner]

What is beginner level material?

[ThomasPowers]

Generally one starts by using cheap easily available mild steel/A36 to make small objects while their skills with a hammer and forge ramp up.  Once you have good control of both you start making larger/more complex projects.  When they become easy to succeed at you start working higher carbon steels generally making tools for the smithy.  When you get comfortable working higher carbon steels (control of forging temperatures, heat treat, etc) then you move into small knives, then larger ones, then finally swords if that is in your game plan.  Finding a local blacksmithing group can save months over trying to learn it on your own---shoot I say one Saturday afternoon with a good smith will save you 6 months of failing and flailing around.

Edited July 3, 2015 by ThomasPowers

[Frosty]

Mild steel to develop blacksmithing skills. 5160 coil spring is a good material to start making blades with as it's more forgiving in the heat treat. However, coil spring is salvage and can be flawed or stressed causing failures. Buying known steel has the benefit of known properties, working temperature ranges, heat treatment and finished characteristics.

Forging blades being a sub set of blacksmithing I recommend a person learn to forge steel before venturing into the more precision demanding craft of blades. There's little to gain making beginner blacksmithing mistakes with expensive materials that you have invested a lot of time and effort in.

For example. Forging leaves is essentially the same process as forging double edged blades with similar problems and techniques but the material is more malleable and less demanding. Once you can crank out long narrow leaves it's an easy step to upgrading the steel and altering the leaf a little.

Before you get to blades you'll have made a number of tool steel tools to blacksmith with, punches, chisels, drifts, hacks, etc. and once you get started folk will just appear that want a wood chisel, etc. soon you'll have heat treatment in hand.

Then one day you'll realize you know how to do all the steps and processes required to make blades. Viola! You're ready to start a whole new learning curve. What will make it better is you'll have flattened the learning curve significantly. You won't have to learn a new craft, just a new material and a couple steps, by then it's a piece of cake. . . Sort of.

Frosty The Lucky.

[ThomasPowers]

I teach a lot of beginners and tell them "everything you do to forge a simple S hook is something you need to do to make a knife"  Far easier to learn it on a more forgiving steel making things that *succeed* than to throw away days and weeks of time failing.

[BIGGUNDOCTOR]

We are starting to see some spillover from the Facebook page Blacksmithing for beginners. They had over 15,000 join in the first year, and are adding hundreds a week more at the moment.  One pattern I have seen developing is "I found such and such item ( Bobcat track, brush hog blade, etc) ,will it make a good blade?". Also with the TV show about bladesmiths they have seen an uptick in likes. I have recognized a couple of names from IFI, and YouTube on there, but it appears to be mostly newbies with ideas of being an instant bladesmith, since the experts , and editing, make it look so easy to do.  

 

As for Tanner, it may be a problem with terminology. Tanner did you mean to say you annealed it in sand to make it soft, then quenched it in water later to make it hard?

I agree about the drill bit if it is HSS. That is not a beginner level material to work with.

The file should be fine, but it sounds like it is hard enough that when you hit the heated area the vibrations/shock snaps the blade in a cooler/hard area. The other problem may be that with files if you just heat and beat , all of the teeth become cold shuts, and stress risers-especially if quenched. I talked with the materials guy at Nicholson files, and he told me that treating their files like W1 tool steel for heat treating would be a good choice. 

 

This sounds like a case of maybe the right idea that was applied in the wrong order, and not articulated correctly.

 

Edited July 3, 2015 by BIGGUNDOCTOR

[Charles R. Stevens]

I have had files in thin sections (awl blades) air quench, or more likely "anvil" quench. 

As to coil aprings, one finds less issues with fatige cracks as they break much less in service than leaf springs

[Tanner]

Yes I annealed it on sand and quenched it in water. 

[Frosty]

Good call Guns, a simple misuse of jargon, easy to straighten up.

Tanner: Sand is a really poor media to normalize let alone anneal with. It has much too high a specific heat, commonly called "Thermal Mass" and it draws the temperature down too quickly for the crystal structure to revert to a soft state. Please note I did NOT use the proper metallurgical terms, I am NOT a bladesmith guy and would have to spend hours reading just to pick up the terms. This is why I'm using descriptive phrases and sentences. I can describe what happens physically but not the crystalography of steel alloys.

To the point, to normalize you bring the steel to critical temperature. Judging by color is very subjective depending on the alloy, the light in your shop including time of day if you use daylight and even your eyes. Till you have experience use a magnet. When the stock becomes non-magnetic it is just below it's critical temperature and PROBABLY close enough for simple alloys. Let it cool in still air.

Annealing is similar but it needs to cool much more slowly. An old technique is to bury it in lime. Personally I think lime is too fast a chill but that's just my opinion and could be wrong. Burying it in perlite is pretty good as well, ash is old time traditional and a good insulator. I either let a piece cool down in my forge after I shut it off or wrap it in Kaowool ceramic blanket and put it in a closed container.

High alloys often require special ovens that ramp temperatures up and down at specific rates and are typically out of the working ability of most home shops. I believe high speed steels like drill bits are in this class of alloy. Again I could be wrong.

I recommend coil spring as an entry level tool steel because the stock is round bar making it easier to forge into various shapes than flats like leaf spring. Leaf spring is used in stacks so there is wear where leaves rub as it flexes. This causes micro scratches which in blacksmith jargon are "shuts". Shuts are sharp cuts or marks that serve as initiation points for stress failures. If you've seen glass cut you've seen the effect of a initiation point failure. The scratch in the glass interrupts the smooth conduction of a shock wave and the glass fails (breaks) at that point. A scratch, chisel mark or sharp indentation in steel acts the same way and can have similar effects. We call it a "cold shut". Anyway, wear marks on leaf spring can be shuts increasing the failure % as working stock. Coil spring isn't in contact with anything and where it mounts in the bracket is not in sliding contact so doesn't suffer scratches. Sure rocks or other road debris dings coil springs but it's a LOT more visible and a GOOD reason to feel the stock. You will feel imperfections with your fingers you can't see without a loupe.

We don't speak an exclusionist jargon, it's a "Trade Jargon" a language with specific terms, phrases and nuaunces for precise communication. All that long winded post I just wrote is just a skim of a couple processes covered by understanding two words.

Bladesmithing is the deep end of the pool little brother, we'll help you learn to swim but the job's really yours.

Frosty The Lucky.

[ThomasPowers]

Dry sifted wood ash is a good annealing medium for many alloys---cheap and easily found/made.  When a piece is too small to anneal well by  itself adding in a helper bar---just a chunk of scrap heated to the same temperature that's put in the ashes together with the smaller piece can make the difference.  (Knife blades  being so thin have a lot of special issues)

[T.J.watts]

watch as many videos as you can find and read as much as possible. study, study , study and then study some more. The more you learn the more questions you'll have and the more reading you get to do lol. Don't get to frustrated and just keep at it.

[Charles R. Stevens]

TJ, i have more reading for you

[Frosty]

T.J.: Watching videos is what put him in this mess in the first place. Anybody but ANYBODY with a video camera and Youtube account can post an "expert" how to video. We spend all too much time trying to undo the MISeducation they cause.

Frosty The Lucky.

[Charles R. Stevens]

Lets qualify TJ's statement, as a special proces wellder he knows enugh to weed out the BS. It's like peaple kiving their opinian of a peice of survival/camping gear, if it isn't put threw the wringer, i dont trust them, same with the smithing, if I dont see the finished product, and in my case I can see buy the hammercontrol i dont trust them ither

[T.J.watts]

Just to clarify watching videos on youtube isn't all bad. No not all of them are worth the time, but some of them are. If you've been studying as I also mentioned then over time you will start to realize which ones are worth watching. Just watching videos isn't enough by a long shot, but it give you a starting point. If you are lazy and won't read a book or try what you've learned then your doomed for failure.

[ThomasPowers]

The problem is that some of the high production value videos are the bad ones and some of the terrible videos are the good ones.  Seems like if anything skill in forging is inversely correlated with skill making videos.

[Charles R. Stevens]

TJ,

How many times have you gone to the shop to "ask the steel" only to have it laugh at you? Lol. I know I have, usualy when there is a witness...

[T.J.watts]

All I'm saying is absorb as much as you can, and some people (me included) have a hard time learning without some visual instruction. Charles, yes I've done that too many times.