01 Plane Iron/Chisel making... Take 2 [Archive] - Sawmill Creek Woodworking Community

Rick Markham

08-13-2010, 4:40 PM

Ok, after many hours of studying hardening and tempering techniques and the "dumbed down" technical explanations I am starting to understand the transformation of austenite to martensite. My head has somewhat stopped spinning a bit.

My question for y'all who have embarked on this journey, I understand "soaking" during the hardening process, how long do you typically "soak" your irons at their maximum temperature? I am going to be using 1/4" stock.

Now since most of what I have been reading is involving knife blades (with different thicknesses) the concerns for warpage during quenching are obviously more profound than with a solid even rectangle will experience (no bevels). So I guess in a round about way, I am asking what quenching oils do you prefer and seem to experience the least amount of warpage?

Have any of you used any of the high temp "salts" to embed the iron in to help control atmosphere and even out the distribution of heat during the hardening process? (I am assuming this would be somewhat overkill for a very even shaped plane iron blank just interested)

What do you guys use to remove the scale after all of this? Elbow grease? An Acid bath? (if so, what is your methodology, lol)

Hopefully this week my steel order will show up and I can start building my plane body, hopefully in the time it takes to finish that part, I will be a little more educated on the whole heat treating processes, and will have a controller for the kiln.

Hopefully I haven't put anyone to sleep with this post... If I have WAKE UP! ... and sorry ;)

Will Boulware

08-13-2010, 4:51 PM

I have nothing useful to add to this thread except to say that i'm also very interested in this and am looking forward to any responses. :D

David Weaver

08-13-2010, 5:07 PM

I can only add comments from a much less scientific point of view.

I heat my irons until just to the point they start to raise flux bubbles, sometimes not quite that.

Then, I quench them in a can of peanut oil. If the oil is thick because the shop is cold, I preheat it some.

I carry it up the steps and put it in the oven for an hour. I have not done any really large irons though. The ones I have done have turned out fine (mostly moulding planes, joinery plane irons and chisels).

I get scale off with a brass wheel.

Rick Markham

08-13-2010, 5:15 PM

Ok, nevermind on the salt thing, I did some reading and it is far too much for anything I am interested in.

David, This is why I posted this here. I'm not making high end knives for market, nor am I making or planning to make plane blades for market. However since I am investing my time and money in this passion, a little overkill of knowledge couldn't hurt. At some point some of this becomes borderline ridiculous. I need y'all to help me sort through the good ideas, and leave the over the top ideas behind.

Harry, George, and you, as well as everyone else who replied in the last thread have been extremely helpful and I am truly appreciative of it!

David Weaver

08-13-2010, 5:19 PM

I certainly don't think there's anything wrong with doing it as well as possible. You may find out you want to make knives.

A well done smoother iron is important - more so, I think, than an iron for a H&R or an iron for a bullnose plane or whatever.

I just have a lot of them laying around (irons), so each time I do a plane, I already have an iron for it. I have a backlog of 5 good quality irons (steve knight, etc) and maybe twice that many old double irons waiting to go in wood planes as soon as I find a few cheap billets of quartersawn beech :( I'll probably get tired of making planes before I get to them all.

If i had the inclination, I'd take the same steps you're taking to try to have more control over what's going on - i'm sort of guessing and testing afterward.

Rick Markham

08-13-2010, 5:34 PM

Well I haven't made it to the finding the wood part yet, I figure I will save that frustration a little farther down the road ;) In the meantime I have a whole lot of metal work and lots of learning to do.

Sounds like you have some plane irons you need to get busy on homes for :D I have two 2" x 18" precision ground billets of O1 coming, so I think I will be set on plane irons for awhile... That's assuming I don't ruin it while figuring this all out :o I am reasonably confident that it will be in my grasp when that time comes though.

Most people would be bored reading all of this information on steel... I actually find it pretty fascinating.:eek:

Mike Siemsen

08-13-2010, 6:47 PM

Rick,
I found the O-1 to be pretty forgiving. Heat it to the Curie point (magnet doesn't stick) quench in peanut oil. bake at 325 for 1 hour to temper. We heated the blanks in a Mapp gas 2 brick forge. All very basic. Work the back and edge up on coarse sandpaper ala scary sharp.
Mike

Roger Newby

08-13-2010, 7:18 PM

FWIW, I just retired after 30+ years as a tool and die maker and did some heat treating of tool steels, but most of it was sent out to the big kids because of the requirements and tight standards for production tools.

As a hobbiest, I found a book by Mike Burton titled Make Your Own Woodworking Tools, you can get it at Amazon. While it deals more with carving tools, it still has a bucket load of good tips for heat treating in a home/shop environment. It's a good read IMO and a great reference for the beginner as well as experienced.

george wilson

08-13-2010, 7:27 PM

The general rule is 1 hour per 1/4" of thickness. You shouldn't have to wait an hour for 1/8". Waiting too long just invites more scale and worse,surface decarb.

I got lucky and just bought a whole roll of stainless steel heat treating foil for about half price. It is the best insurance about avoiding surface decarb,or excessive scaling that is a job to clean off. Trouble with the foil is it isn't cheap,nor reusuable.

For a plane iron size envelope of foil-which should be as close fitting as possible,with double folded edges to not leak air- I put in a piece of brown paper bag about 2/3 the size of a stamp. Too big,and it will burst the envelope open. Just right,and it burns up the oxygen inside it,helping your tool stay clean and decarb free.

Usually,decarb isn't a problem with 01 unless you overheat it. If you decide to get into A2,you will have to get a roll of foil. That is a MUST,or you'll have a layer of soft skin on your A2 parts.

Roger Newby

08-13-2010, 7:37 PM

+1 on what George said about the stainless foil. I meant to mention that as well.

george wilson

08-13-2010, 8:04 PM

I hope you are copying down all this info. It will save you buying a book!! Really!!

Leigh Betsch

08-13-2010, 8:05 PM

When you quench in oil you want to stir it around as is quenches, makes for more uniform cooling. And use enough oil so the oil doesn't heat up. We used to have a 30 gallon tank but I would think one gallon would be enough for one blade at a time.

Tony Shea

08-13-2010, 8:22 PM

I also find all this information fascinating. It really is a must know if one wants to make any of his own shop tools, which is often the case with us woodworkers.

Ron Hock

08-13-2010, 8:23 PM

For O1, the soak time is 5 minutes per inch of the smallest cross section once the color of the part matches the color of the furnace (this according to Bill Bryson's Heat Treatment, Selection, And Application of Tool Steels ISBN 9781569902387). You don't want to leave the part at temperature longer than necessary unless you have an atmosphere-controlled furnace or you'll burn out too much carbon and form a soft, low-carbon skin. For 1/4", just soak it a minute or so and you'll be good to quench.

I've used peanut oil for its high flash point but there are official quench oils that cool the part at a desired rate. Don't worry. P'nut oil will work fine and it smells better. Keep a fire extinguisher handy.

I suspect the high-temp salts you refer to are the ones used in salt-bath heat treating where the part is immersed in molten salt (they used to use lead in the day) so it has no contact with atmosphere. Probably outside your reach -- go with the oven. I used to throw a charcoal briquette in to scavenge oxygen but I honestly don't know if it did any good. You'll need foil for A2 but O1 shouldn't pose any problems if you don't leave it at red-heat too long. There are occlusive coatings -- I had some ceramic/copper paint but it was a long time ago. Look at Rosemill.com for more info. Get your chops down without it but you may want some as your skills improve. I don't think I'd recommend foil unless you're willing to strip it off very quickly between the oven and the quench. I think the foil would interfere with the oil's ability to pull heat out of the part quickly enough if left on.

Yes, it'll be a scaley mess when it emerges from the oil. I used to sand-blast but you can wire-wheel or whatever to clean it up. The surface that will be the flat back of the blade will need to be ground down past the de-carbed layer to expose the properly hardened steel under the scale. A few thou should suffice but if the blade doesn't hold an edge as desired try re-flattening the back and re-test.

Overheating is as bad as underheating. Overheating causes large crystals to grow and the piece will seem hard to a file test but will be very brittle. You may want to acquire some small pieces of O1 to test with (1/16 x 1/4 for instance). Get to know the colors and the drill and when you have a couple of pieces hardened, break one and look closely at the insides. Properly hardened steel will look like gray primer inside -- uniform gray with very fine texture -- just like primer. Overheated steel will distinctly show sparkly crystals. Underheated steel won't be hard and will bend instead of breaking.

Temper as soon as the part has cooled just enough to handle -- don't wait. Tempering is easy by comparison. If you have an oven with temp control that you trust you can just toss in the piece (325F for Rc62) and leave it until you're sure it's come fully to temp then a few minutes more (Bryson says 2 hours per inch so 30 minutes for your 1/4" blade.) No need to quench from the tempering oven, just let it cool or quench if you're in a hurry. You're done. Clean it up, sharpen it and tell us how you did!

Good luck. And be careful.

Rick Markham

08-13-2010, 9:19 PM

Thanks Fellas, that's exactly the advice I am looking for! George, I am definitely taking notes on this, after seeing how much the industry books are, they are out of my reach at this moment. Besides between y'all and the knife forums I have found a wealth of information.

Ron, yes I was talking of the molten salt, after reading the intricacies of it and the dangers, it isn't worth my time or safety for my uses. Maybe if I was setting up a production system it would be of interest to me.

Elbow grease it is, that's pretty much what I had assumed :D

george wilson

08-13-2010, 9:22 PM

Ron has said about the same thing as I did. Don't let the blade stay in TOO long. Personally,I haven't had trouble with 01 decarbing,but I know how to NOT overheat it.

Your oil probably will catch fire when you quench the blade. Just use LONG tongs,and keep your head low. It will go right out. However,make sure you are working where some soot accumulation isn't a problem.

You need a quench LARGE ENOUGH that a blade doesn't heat it up. I used a 5 gallon bucket with probably 4 gallons of automatic transmission fluid in it at work.

ALSO had a gallon gan with a tall wire handle that stuck up out of the quench. There was wire mesh on the bottom of the bottomless can. It was handy for dropping in small things,then lifting the can out to get them. You don't really have to have that,but It is useful to know about.

P.S.: It is best to cut the bottom off of the stainless envelope. Let the blade drop out onto some DRY bricks. Grab it ASAP!!! and quench it. The metal cools fast. A GOOD FAST assistant would help!! Otherwise,your metal might not harden,because in a jiffy,the edge goes black. Some say that A2 will harden in the envelope,but I take it out.

Just don't worry about the foil wrap with 01. You have enough to learn anyway,and it was YEARS before I started to use the foil. Just clean the blade. You'll be fine. Save the foil info for when you decide to get fancy and go to A2.

ALL the planes I posted pictures of,now in FAQ section,have 01 blades.

Wes Grass

08-13-2010, 9:44 PM

"I think the foil would interfere with the oil's ability to pull heat out of the part quickly enough if left on."

You'll *never* get it out of the bag fast enough for an oil/water quench. At least for something that thin. A 1"+ block is another matter.

PBC anti-scaling compound can be run right into the quench if you want the parts clean. But probably not worth the expense for a couple pieces.

And at the quench, there should be no hesitation at all. Get it in there, take the plunge. Dawdling will get you a fire. And you want to go in 'on edge' ... which is really the only way practical if it's in tongs ... but still ... in like you're slicing the oil with it. Not sideways like a stirring paddle. The leading side will cool quicker and it's more likely to warp.

Ideally the quench oil is warm, but I don't think it's critical for something like this.

george wilson

08-13-2010, 11:06 PM

I have gotten 01 irons out of the foil fast enough,BUT I've had lots of practice. As said, he doesn't really need the foil anyway for 01.

If you want an inexpensive coating for your blades,mix up a THICK batter of wheat flour,about 1/2 cup. Add 1 teaspoon of yeast,and a pinch of salt. Mix in water to make a THICK batter. Paint,or dip your iron in this. When you heat the iron up,it will burn up,leaving a thick layer of carbon on the blade. The carbon will protect the blade from getting scale,but it will smell like burnt bread,and be a bit messy to get off after the quench. However,your blade will look about like a new file. Recipes like this were used in past years to protect tool steel surfaces. In the 18th.C.,Peter Stubbs' files were dipped in 'beer leavings" to protect the teeth from the fire.

I have used this mix many times. Last week I told another guy about it. He tried it,and was delighted.

It isn't quite as good as PBC No Scale compound. It is cheap and easily made at home,though.

I agree with Wes's advice on quenching.

Jamie Bacon

08-13-2010, 11:31 PM

The only thing I've ever heat treated is some striking knives I made from 1/8" thick W1 steel. I heated them with a MAPP gas torch with the knife blank on a bed of charcoal. I heated the steal until a magnet would no longer hold the steel. Then quenched in a can of peanut oil and put it in a toaster oven at 425º for about 45 minutes which brought the steel to a nice straw color. Finished the final tuning of the bevel after the tempering. Not sure if all this is right, but the knives turned out great and hold their edge well.

Jamie Bacon

Rick Markham

08-14-2010, 2:24 AM

George, I will definitely save the foil method for A2 if I ever decide to go that route. That sounds like an interesting recipe, I will have to give it a try. I will start out without it to see what kind of scaling I am getting. The burning bread smell isn't an issue, the kiln and the quenching tank will be in a open (but covered) carport. I was planning on using about 3 to 4 gallons of oil (probably will be peanut but ATF isn't out of the question either) I have a fire extinguisher, and plan on having a "lid" to toss on the container should it catch on fire. The can with a mesh bottom is an excellent idea that I had not considered definitely a worthy investment.

Wes, yeah, I read a great deal about preventing warpage when quenching, making sure that the surfaces get as even flow of oil around them as possible. Slicing it rather than using it as a paddle. I understand the concepts of the vapor layer forming, then the collapse of the vapor layer, and then the subsequent "violent" reaction of the liquid reaching the bare metal. (sounds exciting) My understanding is that heating the oil above 100F is generally just to decrease the viscosity and help with the convective motion of the oil exposing the blade to as large a volume of the quenching oil as possible, also helping to prevent the vapor layer from insulating the steel for longer than it should. I also understand some of the specific quench oils have "working temperatures" so their cooling curve is accurate.

A few people had discussed using a small pump to help circulate the oil in the tank. (I have some submersible aquarium pumps that are expendable, I wonder how long it would take to cook them LOL :D) Honestly it seems that it would be hard to make sure there was uniform oil movement over the blade with that.

Thinking about the situation, I would think that a tall skinny quenching tank would lend itself best to natural movement of the oil due to convective action, or it might simply over heat a small region of the oil if the viscocity it too high and be completely counter productive. What are y'all's thoughts on an ideal shape for a quench tank? You have the experience, I only have ideas at this point.

Edited to add: Yes I have a good set of blacksmith tongs (13" handles) and a heat/ fire resistant sleeve. I also do not plan on having any portion of my body anywhere above the oil ;)

george wilson

08-14-2010, 10:32 AM

We just used a 5 gallon pail. You can't cover the lid when you are holding a blade in the quench. The oil will catch fire around the blade,not all over. Just get the blade fully submerged and the fire will go right out.

I never heated the oil and did fine. Just don't let the oil get cold. Keep it at room temperature. You could get in trouble trying to heat the oil,and have the whole thing go up in a huge fire,burning your house down. The insurance co. won't pay for it,either. In fact,if they knew you had a furnace,you might get your insurance cancelled.

My journeyman Jon had his insurance cancelled because he had a small forge 100 YARDS from his house. Ridiculous as it seems,he had to find another insurance co. that was more sensible,so be very careful.

Bob Strawn

08-14-2010, 3:15 PM

Stainless foil is great stuff, I am too cheap to use it, so I use the very next best protection. I mix a touch of iron oxide into boric acid crystals. I make a thin paste by adding water and then I paint it onto the steel. This becomes a soft glass coating on the steel when it heats up. Boron is great stuff for preventing oxidation, this is why welding rods are coated with the stuff.

I heat my quenching oil to boiling and test with a drop of water to make sure that all water is out of the oil. Oil can take up quite a bit of water from the air, and that water will make the quench splatters more violent and can give you an uneven quench.

Over heating oil will denature it and cause oil to become lacquer. Oil and lacquer have different quenching properties, so old oil and overheated oil can cause uneven quenches due to the separated mixes.

I let the oil cool down to the point where it is no longer too hot to maintain skin contact with. Warm oil is less viscous, and the curve for quench speed is more influenced by viscosity than temperature. As a result warm oil will quench faster. Since the thermal shock is lower, the steel is also less likely to deform in warm oil.

Before I quench, I stir the oil so there is a nice spin in my quenching solution. This is how I maintain circulation when quenching.

My favorite oil for quench is grapeseed oil. For me, it never flames up. It does not keep as well as a lot of other oils, but a flame up can quickly heat oil to the point where temper can be ruined. I hate emergency issues while working with hot steel.

Don't use too little oil in contrast to the amount of steel being quenched. There needs to be enough oil to even out the heat from the steel, without being raised to too high a temperature.

Bob

Rick Markham

08-14-2010, 4:38 PM

George, yeah I hadn't thought of the insurance aspect of this. I wasn't planning on heating the oil, here in florida all I have to do is leave it outside LOL. Ok, I understand now that you hold onto the blade through the whole process, that makes sense (major detail not mentioned anywhere else, probably common sense as well ;)) 5 gallon bucket it is, the price is right too.

Bob, I had thought about the stirring the tank before quenching, I am glad to see that someone uses this idea, it seems the most sensible. Where does someone get grapeseed oil? What's its smoke point? Flash point?

I will only be quenching one iron at a time as this is a learning experience at this point, and probably 3 or 4 gallons of oil (depending on how big of a steel bucket I can find)

george wilson

08-14-2010, 6:29 PM

I haven't used grapeseed oil,but it is known that grapeseed does have a higher temperature resistance than other COOKING oils. You could probably get it in a high class supermarket. I haven't looked for it myself. That said,I don't know how the cooking oils compare to other oils like automatic transmission fluid. You could google everything and probably get some temperature data.

Sorry,I didn't mention keeping hold of the iron with some long blacksmith type tongs.

Insurance can be a real pain. They also don't like dust collectors. They probably would scream if they knew anyone had any of the woodworking machines,in case someone hurts himself in your shop and wants to sue you for the deep pocket insurance.

Rick Markham

08-14-2010, 6:44 PM

It's funny that you mention that George, because after I replied to your post I thought about that very fact. If my home owners insurance saw my front porch (my shop area) and saw all of the "dangerous" machinery and sharp objects in there, they probably would cancel my insurance anyway LOL.

In all likelyhood I will end up using ATF, I think on a cost basis it is going to be the most affordable for me. If I am going to spend a wad of cash on quenching oil I would invest in one of the commercially available quenching products.

Don't worry about not mentioning holding the iron with tongs, no one else even on the blade forums mentioned either. I think it is an piece of info that most consider common knowledge... I just ain't common :D

Wes Grass

08-14-2010, 7:54 PM

Somebody once told me a story about a Swiss file maker they toured, or saw a movie ...

They didn't hold onto the files with the tongs. They threw them into the quench (water) which was running in a sluice. This was not a random throw either, they were very skilled at tossing them from the tongs so they entered the water end on like a dolphin.

Just a possibly interesting anecdote. Don't try this at home ;-)

Andrew Recher

08-14-2010, 7:55 PM

Peanut oil works well too. Back in my amateur knife making days, I asked a local place if I could dip a few gallons out of their used barrel and they said no problem. It smells like french fries when you quench and I think it has less chance of having toxic junk in the smoke than say...ATF or motor oil. Peanut oil also has a fairly high flash point for a vegetable oil.

george wilson

08-14-2010, 8:43 PM

I guess I should be dead from using ATF fluid for years,but somehow have survived by making it a point to keep my head out of the smoke.:)

Bob Strawn

08-14-2010, 11:37 PM

I get my grapeseed oil at an Oriental Grocery. Peanut oil works quite well, but it is the messiest to clean up of any of the edible oils I have used. Caster oil is worse, but I don't consider that stuff edible. I have mixed oils, and have not liked the result. As long as I can continue to get grapeseed at a reasonable price, I will keep using it.

Bob

Rick Markham

08-15-2010, 2:35 AM

I agree Tony, that is exactly why I am embarking on this. I have enjoyed fettling old planes and tweaking new ones almost as much as I do woodworking. I have always had an interest in tool making, and honestly have had a great deal of fun, just researching and studying all of this. I am excited to get started on making some of my own planes and chisels, blades and all ;)

george wilson

08-15-2010, 9:37 AM

Wes,I'm not surprised about the file tossing story. It is also true that often files have to be straightened after hardening. In fact,I once bought a large bunch of NOS files,and found that the long angle lathe files were twisted like a propeller,but somehow sold that way.

They have 2 uprights that the files are straightened between. These uprights are made of some material that won't hurt the file teeth. Maybe wood,or lead. The files are heated up to the tempering temp,then caught between the 2 uprights and bent till straight. As long as they are hot,they can be bent without breaking. When they are straight,they are left to cool.

I have used this technique myself many times. For example,a flat sided reamer for lute pegs. Being half round,and about 6" long in the half round area,it warped like crazy when hardened.. I just made a block of wood with 2 dowels about 1/2" apart in it The dowels were 3/4" dia.. The block was held in a vise. I was able to bend the reamer like it was rubber till straight. When cool,it would snap in half if you tried to bend it.

Ron Petley

08-15-2010, 10:50 AM

Coll Project!
I have done a few O1 and it was fun and they came out well.
You will need something to heat the steel evenly, I heated mine from the back of the blade as to not over heat the cutting edge, then the heat can creep into the cutting edge. Check with a magnet when you are at temp. If you can hold it their for a min or two good on Ya, just so the heat gets to the inner part of the steel.
With mine I started the bevel on the blade and left some to do later so the point would not overheat and I had some outer steel to remove after heat treating. The point was a little thicker than a quarter (coin).
I quenched mine in Canola oil, I do not think the oil is all that important unless you have Parks. I heat mine to 135 F. I have 8 liters of oil, but I do not do a lot of blades at once.
Quench it as fast as you can and leave it in until the oil has removed the heat from the inside of the steel. Remove it when it it about 400F, just hot enough to touch it quickly and the oil is not smoking.
Watch your oven, regular ovens have big temp swings. So pre heat and put your blades in sand to even out the temp. I go 2 hours at 350-375is depending on how hard you want the bade, lower temp harder, but chippier.
I do not think you will be able to heat 1/4" with a brick forge, but worth a try.
Are you going to do the final edge by hand?
Skip the salt bath, way to dangerous.
Got a few repeat photos in their but that is my set up anyways, you can see in one photo a round can of oil, in the next I have replaced it with a bigger can, a ammo can that has a lid, spilling that stuff is a mess. .
I think if I can do it so can you it is not all that hard once you get set up, As you can see I built a forge out of a Bar-B-Q tank and the burner is a venturi made out of a pipe, about all I needed to build it was a pipe some plumbing parts and a drill press.
Cheers Ron.

http://i50.photobucket.com/albums/f333/mookie098/P1012268.jpg
http://i50.photobucket.com/albums/f333/mookie098/P1012786.jpg
http://i50.photobucket.com/albums/f333/mookie098/P1012838.jpg
http://i50.photobucket.com/albums/f333/mookie098/P1012842.jpg
http://i50.photobucket.com/albums/f333/mookie098/P1012840.jpg
http://i50.photobucket.com/albums/f333/mookie098/P1012268.jpg
http://i50.photobucket.com/albums/f333/mookie098/P1012786.jpg

Ron Petley

08-15-2010, 11:05 AM

I put up a post, but it seems to have gone AWAL, so here are the photos anyways:mad:
Cheers Ron.
http://i50.photobucket.com/albums/f333/mookie098/P1012838.jpg
http://i50.photobucket.com/albums/f333/mookie098/P1012842.jpg
http://i50.photobucket.com/albums/f333/mookie098/P1012840.jpg
http://i50.photobucket.com/albums/f333/mookie098/P1012268.jpg
http://i50.photobucket.com/albums/f333/mookie098/P1012786.jpg

Bob Strawn

08-15-2010, 1:30 PM

I had a few blades warp a bit during tempering, so I changed my methods. I use a frydaddy now. because the tools are immersed in oil, there are few sudden shocks to the temperature, and the temperature range is more even. I use an immersion thermometer to be sure. It does not seem to be a problem when the temperature dips a touch, what you don don't want is the temp to go over your desired setting.

The only real downside is the size limitation.

Bob

Rick Markham

08-15-2010, 4:11 PM

Ron that is a pretty slick set up! What substance do you have the irons stuck in during tempering? (looks like crushed coral)

Rick Markham

08-15-2010, 4:22 PM

Ron, it is still there. It's farther up in the thread under "more replies below" It's on the other "branch" of this thread. Sometimes these threads get increasingly hard to follow, it's easier to scroll through the tree in top of the thread to figure out where the new posts are, they appear as colored folders next to the names ;)

Bob, that's an interesting idea that I haven't heard of yet. Guess ya probably wouldn't want to make french fries in it after tempering :D

Ron Petley

08-15-2010, 7:43 PM

Thank you Rick.
Here is a forum that might have some info for you:
http://knifedogs.com/forumdisplay.php?124-Heat-Treating-Forum-on-KnifeDogs

Nothing exciting just sand in a old chicken roaster, also I have a oven thermometer as our oven is not even close, which is not all that rare.
The sand will help smooth out the swings as the element comes on and off.
The great thing with 01 is you can do it over again if it does not work out for you. I ended up leaving the scale on my blade, it was black and this has kept it from rusting, 01 will rust if you just look at it. With hind sight, the next try I will round the corners of the non cutting end of the blade just a little.
I can see your oven from your other thread it will be a piece of cake for you and you will be making blades for all your friends and then some.
The other high carbon steel like 1095 is a lot cheaper, I have one on the make to see how it holds up.
Something I forgot to mention, if you heat your blade to non magnetic and then take it out and let it air cool. Do this twice and you should not have any warping. This is done before quenching and is called normalizing, since I have started doing this I have never had a blade crack or warp.
A little piece of wood in with the blade will consume some of the oxygen and reduce the scale.
Keep us posted. Cheers Ron.

Kevin Lucas

08-17-2010, 12:09 AM

Dang Ron you just got me in the dog house. She came up behuind me and "what is that?" I explained heating, quenching and tempering. "NOT IN MY OVEN YOU DONT!!!" oh well...

Rick Markham

08-17-2010, 12:48 AM

Dang Ron you just got me in the dog house. She came up behuind me and "what is that?" I explained heating, quenching and tempering. "NOT IN MY OVEN YOU DONT!!!" oh well...

Just get your own oven :D

Ron Petley

08-17-2010, 1:11 AM

Get a cheap toaster oven, or a garage sale one, and wrap it in insulation and you will be good to go. Or will the oven you bought go down to low temps?
My wife never said anything, course she is at work when I am cooking steel, sometimes I make ribs when I got the oven on. I keep the roaster in my workshop, far as she knows she chucked it out long ago.
Well gotta go with the flow, keep her happy and blame it on me, I live far away so I am safe. :D
Cheers Ron.

Derek Cohen

08-17-2010, 2:30 AM

OK, I would like some comments on the most low tech method I know of heat treating a blade. Let's call this a learning experience and I will takes the lumps and criticism.

Here is the situation ...

I made a chisel yesterday for a woodworking friend. The basis of the chisel was the blade out of a black, plastic handled Stanley I have had for 10 or more years. The steel is reasonable, a bit on the soft side to hold an edge for long, and the black handle is just plain Horrible.

I wanted to turn this into a nice looking chisel that could be used for paring dovetails. First thing I did was to wack off the handle (easily done with a hammer), and then ground the shoulder of the blade until they were narrow (there is a pictorial on my website). This was the result. You can see the interesting tang ...

http://i13.photobucket.com/albums/a262/Derek50/Chisels/Making%20a%20chisel%20blade/1a.jpg

Incidentally, the Marples/Irwin blue handle chisels look the same.

The heat treating was done with two butane torches ...

http://i13.photobucket.com/albums/a262/Derek50/Chisels/Making%20a%20chisel%20blade/1.jpg

Alongside is a tin of peanut oil for part-quenching. Why "part-quenching"? Because I have no idea what the steel is. I suspect it is a O1 type rather than a W1 type. So I plan to quench in oil (which can be too slow for W1) and then re-quench in water. I have done this before successfully - any comments?

I do not heat the steel to cherry with the lights on. It is difficult to judge colour in the light, so the lights go off and I am left with a gloom.

http://i13.photobucket.com/albums/a262/Derek50/Chisels/Making%20a%20chisel%20blade/2.jpg

I did not think to take a picture of the cherry (partly because it was difficult, but mainly because I only thought of pictures after this stage!). So just imagine cherry red for the first 2" of the blade. Then dunked in peanut oil until still warm, and then under cool water.

A file slides off the steel (i.e. the steel is harder than the file), so I consider it ready for the next stage.

First I clean off the blackened steel with fine sandpaper, getting back to a bright surface (all the better to see the colours in the next stage). So it is time for tempering.

Back to the torch - this is what I meant by low tech. I start about 2" back, get the steel hot and watch the colour changing as it moves along the blade towards the bevel end. As it get the palest of yellow I immediately quench it in the oil and again the water.

Here is a picture. The flash has made the yellow a little whiter than it actually was, but the steel was a faint yellow ("straw") at the tip.

http://i13.photobucket.com/albums/a262/Derek50/Chisels/Making%20a%20chisel%20blade/3.jpg

The blade is now cleaned, lapped on 400 grit diamond stone, 1000/5000/12000 Shaptons - however I must point out that only the last 1" behind the bevel was lapped to 12000.

http://i13.photobucket.com/albums/a262/Derek50/Chisels/Making%20a%20chisel%20blade/Backofblade.jpg

The final chilsel looks like so ..

http://i13.photobucket.com/albums/a262/Derek50/Chisels/Making%20a%20chisel%20blade/5.jpg

http://i13.photobucket.com/albums/a262/Derek50/Chisels/Making%20a%20chisel%20blade/4.jpg

The proof of the pudding lies in the eating. Paring endgrain Radiata Pine (Truly Horrible Stuff) ...

http://i13.photobucket.com/albums/a262/Derek50/Chisels/Making%20a%20chisel%20blade/6.jpg

It held up well in very hard wood as well. This is Wandoo endgrain - one of the hardest woods in the world. I kid you not.

http://i13.photobucket.com/albums/a262/Derek50/Chisels/Making%20a%20chisel%20blade/Wandoo.jpg

Comments?

Regards from Perth

Derek

Rick Markham

08-17-2010, 5:26 AM

Derek, My comment is that I like it! :D My favorite part is the description of how you removed the handle.

Rick Markham

08-17-2010, 7:29 PM

My Tool steel showed up today :D

http://img.photobucket.com/albums/v295/Rick357/008-4.jpg

Derek, ya inspired me to try my hand at "fixing" one of my black handled Stanley's today... I spent some time free handing the bevels on the Tormek, Then I looked at your set up on your webpage... I know... I do things bassackwards sometimes. I think my black handled Stanley's are a "crappier" version of what you had. Mine are only 8 or 9 years old, and have never been worth a dang. It actually works pretty decently now. Still need to fix the handle though... now I need a lathe...LOL

http://img.photobucket.com/albums/v295/Rick357/006-3.jpg

http://img.photobucket.com/albums/v295/Rick357/005-5.jpg

Sorry for the gratuitous bench top shots, I just reflattened/finished the top, I managed to get most of the battle scars out. I put tung oil on it (since that is my most used finish) I figure I can schlep a coat on every now and then.