Hand Sanding a Blade

Hand Sanding a Blade

Hand sanding is an effective, if slow, way to finish a forged knife blade. While it can be done with power tools, they are not essential to do the job. I recommend beginners approach sanders and buffers carefully, as they are among the most dangerous tools in the shop.  It’s easy to make a mistake, and compound it so fast as to ruin a piece because of it. Working by hand is slower, true, but the end result is likely to be better, especially if you’re willing to put even a modicum of care into the work.

Step one is to get some paint stirring sticks from your neighborhood box store. Usually, they’ll give you a handfull for free.  Barring that, small bundles of them are inexpensive in the box store paint departments.

Wet/dry sandpaper

Different brands of wet/dry sandpaper will be available in different areas, but they all do the same job.

Step two is to go to the auto parts store and get a selection of wet-or-dry abrasive paper. These can often be bought in sample packs with a variety of grits in one pack for around $10-$15.  An 80 grit paper is coarse, and for surface rust you probably won’t need it, but for deep pitting it could come in handy. You need a variety of progressively finer grits; 120-150, 220, 320, 400, 600, and if you really like mirror finish, you might go to 800 and 1000 grit. I like a satin finish, myself, and don’t really like anything over 600 grit. But it’s a personal decision.  If you’re really into the mirror polish, sandpaper is available up to 2000 grit fine paper.

The sandpaper in these variety packs comes in a strip or a sheet. It’s acceptable to tear these into more manageable sizes, if the full size is awkward to use. If you fold the paper where you want to tear it, it’s easier to get a straight tear along the fold line than if you simply tear without pre-folding. You can also cut with scissors, but it’s hard on the scissors.

You want to select the finest grit of paper that will get the job done. Only experience will inform you how to make that decision. If you start with too fine a grit, it takes too long and uses too much sandpaper to get the job done. If you start with too coarse a grit, you’ll spend too much time and finer paper removing the scratches from the coarse paper.

Sandpaper and sanding stick

This shows 80 grit sandpaper wrapped around a sanding stick.

Wrap a piece of sandpaper around your paint stick so you can hold it securely to the stick and keep it flat against the stick as you sand. I usually start along one edge of a flat side of the stick, lay the paper across that flat side, roll it around and across the other side of the stick, then back around and over the first layer, tearing it off on the opposite edge of the stick from the first edge of the paper. You should have a stick wrapped with sandpaper all the way around, with a single layer on one side and two overlapping layers on the other. When one of the overlapping layers gets dull, you can swap the overlap and use the other. Even the paper on the edges of the sanding stick have tooth, and you can use them, as well.

Now, place your blade where you can work on it. If you can dismount the furniture (guard, handle, pommel) to work on it, so much the better. If not, you’ll have a hard time cleaning the blade right up to the edge of the guard without doing any sanding damage to the guard. You can put masking tape over the guard to protect it from the sandpaper if you can’t remove it from the blade.

You want your blade to be secure while you work on it. I use a clamp to hold the blade to a narrow board (a 1″x2″ lath from the box store is a good choice), so that the blade is supported by the board when I push down with the sanding stick. If your board is long enough, you can also clamp it to a table, etc., so the blade is sticking out where you can get all around it. Some clamps from the hardware store that have rubber jaws that won’t mar your blades would be a good choice to use.

Blade clamped to sanding support

Support most or all of the blade, so it doesn’t flex while sanding. This will help keep the planes of the blade flat and true.

When your blade is ready to work on, squirt a few drops of light oil on it to use with the wet-or-dry sandpaper. The oil is the ‘wet’ that the name refers to. Now use the sandpaper wrapped stick like a file over the surfaces of the blade that need rust removed. Do your best to keep the stick flat and parallel to the flat surfaces of the blade to keep the blade geometry crisp. If you ‘wallow’ the sandpaper around carelessly, you’ll round over edges of planes on the blade that should remain crisp. If there are special shapes on your blades, like fullers, you can grind the end of a paint stick to custom fit in the shape, and tear narrower strips of sandpaper to sand inside those special shapes.
(ADDENDUM: Since initially writing this, I have found that Windex is a suitable substitute for light oil in this process, and considerably easier to clean up when you’re finished.)

The process for sanding with progressively finer papers is to pick a direction (for instance, either the length or the width of the blade) and sand in that direction until all pitting or surface rust has disappeared. Then, select the next finer grit of sandpaper and sand at a 45 degree angle to the first pass, remembering to use the oil. The scratches from the previous grit of sandpaper will show because they are at a different angle to the ones you are currently making. Keep sanding with the new paper until all marks from the first paper have disappeared.

When you have achieved that, again select the NEXT finer sandpaper and while remembering to use your wetting agent, sand at the OPPOSITE 45 degree angle to your original longitudinal sanding stroke, which will be 90 degrees to your previous pass. Again, sand until all marks from the previous sandpaper have disappeared.

It’s okay to use a rag and wipe the blade frequently to check your progress. Then, just reapply wetting agent and keep going if there’s more to do.

Your final pass will probably look best if it is longitudinal to the blade, simply because that’s the easiest way to take long, smooth sanding strokes. But in the end, finish with strokes going in whatever direction will give you the appearance you like best, whether it’s along the blade or across the blade, or any angle in between.

It helps if you can approach the work with a kind of zen attitude, or if you get as much pleasure from the process as you do from the product, like I do. Otherwise, this will likely be tedious for you. Power tools can make this go quicker, but they can also ruin things MUCH quicker, which is why I discourage their use in this application for new smiths.

Knife hand sanded to 600 grit finish

Knife hand sanded to 600 grit finish

How High Should My Anvil Be?

How High Should My Anvil Be?

There’s a lot of debate about what the correct height to set your anvil should be. Some ‘rules’ about anvil height stem from folkloric rules of thumb, like “at the height of your knuckles when your arm is relaxed at your side and you make a fist.” That will work well for some people, but will be too low for most.

What you want is an anvil height where when you work you stand upright and not hunched over, and your hammer lands flat and parallel to the anvil when you use your natural swing while forging the thickness of stock you use most often. That is usually around wrist height, but your mileage may vary.

Here are a couple of sketches gleaned from the interwebz that illustrate what happens if your anvil is too high or too low, as well as an excellent method of testing to determine whether your anvil is too high or too low.

Illustration of an anvil too low for the user

Illustration of an anvil too high for the user

Photo of a board with hammer marks

If you’re struggling to find the best anvil height for you, or if you share an anvil with people of different heights, consider making an Adjustable Height Anvil Stand.

 

A Broad Overview of Heat Treating

A Broad Overview of Heat Treating

Heat treating is a multi-step operation, though not every step is necessary for every heat treatment. The four steps of heat treatment are:

ANNEALING – heating to just above ‘critical’, or phase change temperature, the point at which the steel becomes non-magnetic, then putting the steel in an insulating material like hardwood ashes or vermiculite so that it cools slowly. This will make the steel as soft as it is possible for it to be when it cools.

It is not necessary to anneal a steel before forging, as being at forging temperatures makes all steels soft and removes all previous heat treatment. You anneal so the steel will be as soft as possible while you do cold work on it, like drilling holes or filing.

NORMALIZING – heating steel to a temperature about 100 to 150 degrees above ‘critical’ temperature and cooling in air to black heat, that is, until it loses all incandescent color. This allows the carbides to evenly distribute throughout the steel and normalize (make uniform) the grain size.

Since most smiths have no accurate way to measure temps to ‘100 to 150 degrees above critical’, it is typically heated to just above non-magnetic for normalization, usually to good effect.

Normalizing is only one cycle, done once, and is followed by grain refinement cycles, which are a slightly lower temp each succeeding cycle. People refer to this whole process as normalizing, but normalizing actually grows grain slightly while evenly distributing carbides. It’s then followed by 2-4 grain refinement cycles.

Chart showing five levels of normalized steel

HARDENING – In order for a steel to be hardened, it must have enough carbon. How much is “enough” depends on what you want a tool made of that steel to do. The lower the amount of carbon in the steel, the less hard it can be made.

You achieve hardness by heating the steel to just above ‘critical’, or phase change temperature, then cooling it suddenly in an appropriate quench medium, which may be different from one type of steel to the next, or one cross section (shape) to the next. This causes the steel to be as hard as it can be, but for most steels it introduces a certain amount of brittleness. How much brittleness depends on the amount of carbon in the steel, the cross section of the steel, and what alloying elements are in it. Carbon is the dominant factor in deciding how hard a certain steel can get. Different cross sections of steel can have hardenability dramatically affected by other alloying elements.

Things like chrome, nickel, vanadium, etc., increase hardenability, meaning the steel will harden with a slower quench. This is important because thicker steel cools more slowly. Not just the inside, which is obvious, but also the surface because it is receiving heat from the hot interior. A steel that will fully harden in water when it is 1/8″ thick won’t do that if it’s 4″ thick – unless it is alloyed for high hardenability.

‘Quench’ simply means to cool rapidly. In metalwork, each steel has an optimum cooling rate for hardening, and therefore an optimum quenching medium. Oil quenches more slowly than water, water quenches more slowly than brine. Quenching is part of hardening, but the terms are not interchangeable.

Rule of thumb:

Fast oil <10 seconds, for Wx, 10xx, etc

Medium speed oil 10-14 seconds, for 5160, 80CrV2, etc

Slow oil 14-18 seconds, for O1, etc.

You need to use an oil that matches the quench speed of the steel. For example: for 10xx steels you need Parks50 to quench the steel from critical to 800F in 1 second or less, for 5160 you need an oil that does this in 5-6 seconds, and for O1 10 seconds. Too slow and you don’t get maximum martensite conversion. Too fast will get you maximum martensite conversion but you’ll also get either surface cracks or micro fractures in the steel or both.

And lets not forget that certain steels require air quenching, or plate quenching or salt baths, etc.

So when someone asks “what oil should I use for quenching?” you also need to tell us what steel are you quenching.

One thing to point out that might not be obvious or maybe confusing to a new smith is that steels need to be quenched to below the pearlite nose in a specific amount of time. For example:

Wx and 10xx in <1 second

5160 in 5 seconds

O1 in 10 seconds

But quenchants are measured as the time it takes to cool a nickel ball from 1625F to 670F (These numbers I pulled off the web and not all have been verified):

Brine: ~4-6 seconds

Water: ~5-6 seconds

Parks 50: 7-9 seconds

50 Quench Oil: 7-9 seconds

Houghtoquench K: 7-9 seconds

Duratherm 48: 7-9 seconds

Parks AAA: 9-11 seconds

Duratherm Superquench 70: 10 seconds

Chevron Quench 70: 10 seconds

130F canola: ~10-11 seconds

Duratherm G: 10-12 seconds

Houghton Quench G: 10-12 seconds

Gulf Super Quench 70: 10-12 seconds

Gloc Quench A: 10-12 seconds

McMaster Quench Fast: 11 seconds

Citgo Quench Oil 0510: 14.5 seconds

Citgo Quenchol 521: 16.1 seconds

Citgo Quenchol 624: 17.0 seconds

Mcmaster Quenchall: 28 seconds

 

TEMPERING – Tempering takes a hardened piece and reheats it to some specific temperature to reduce brittleness and increase toughness. The necessary temperature is determined by the type of steel and the specific use for the implement made of that steel. A straight razor will have a different tempering temperature than a spring made of the same steel.

Temper pretty much IMMEDIATELY after the quench. Some steels when hardened have internal stresses that will lead to cracking of the hard but brittle steel. Tempering right away reduces that possibility.

Exceptions to this are if the particular steel calls for a period to “rest” prior to redraw. Not likely you will encounter such a steel, but there are some very unusual alloys that have unusual heat treat requirements.

 

Bars of steel colored to depict progressing temperatures

An excellent resource (in North America) for heat treat information on most available steels and steel alloys is Heat Treater’s Guide Companion. It’s a free download for either iPhone or Android platforms. While intended for industrial heat treaters, it has lots of useful information for the blacksmith.

Written by Kirk Sullens

Henry Vila

Shane Stainton

Austin Hillrichs

Andrew Vida

*****************************************************************************************************************************************************

Temper colors are caused by oxidation of clean steel surfaces at specific temperatures. What color you get is dependent on the temperature your steel reaches…IF IT GETS UP TO TEMP QUICKLY. That causes the oxide layer to form and get thicker quickly, so in SOME circumstances the color is a helpful guide to estimating tempering temperatures.

The problem with depending on that is that a number of things affect those tempering colors; any residual oil on the steel surface will change the color of the oxide, as will lengthy heating cycles. Left at a specific temperature for long enough, a steel can run through ALL the ‘tempering’ oxide colors, even though the steel may never reach the temperature associated with a particular tempering color from a short heat cycle, simply because it stayed hot long enough for the oxide layer to thicken. So TEMPERING is about TEMPERATURE, not color.

The other issue is that home cooking ovens DO fluctuate in temperature. On top of that, the temp that your oven dial indicates may not accurately reflect the actual temp your oven reaches. Your oven cycles. It gets up to temp, then cycles off until the temp drops below a certain point, then it heats up again, just like your home furnace in wintertime.

What I do to address the cycling is to buy 3 oven thermometers (usually around $10 each at the grocery store) and put them in the oven and set it for 400 degrees (as an example). When the oven says it has reached 400, I check the thermometers to see if they agree with that temp. If they do, you can be fairly confident that your oven dial is accurate.

Since the oven thermometers can sometimes be inaccurate due to rough handling in the store, I look for any two that agree. If two agree, but are different from the oven dial, then calculate the difference between the dial reading and the thermometer reading so you know where to set the dial to get the actual temp that you want.

Since the oven cycles, but I want a blade, or hammer, or any other tool to remain as close to the desired temp as possible, I bury the steel in a cheap pan full of clean sand and put it in the oven. The sand will heat up with the oven, and your steel, but will cool down more slowly than the oven when it cycles, so it moderates the temperature. So long as the oven doesn’t go OVER the temp it’s set for, you won’t ruin the temper of your steel, no matter how long it’s in there.

 

Beginner’s Guide to Everything

Beginner’s Guide to Everything

WHAT DO YOU NEED TO GET STARTED?

Just about the BEST thing you can do getting started is take a class from an experienced smith. This helps you in a number of ways; first, you get a chance to use someone else’s equipment, which helps you determine what you MUST have, and what you only desire; second, in-person instruction has the nuance that books and videos lack (do it THIS way, not THAT way); and all that on top of the basic lessons you get.

WHAT BASIC EQUIPMENT DO YOU NEED?

You need (in no particular order) 1) something to hold the fire, 2) fuel for the fire, 3) something to deliver air to the fire, 4) something to forge with, 5) something to forge on, 6) and something to forge, and 7) something to hold hot material that you cannot hold with your hands.

SOMETHING TO HOLD THE FIRE, FUEL FOR THE FIRE, AND AIR DELIVERY TO THE FIRE:

Okay, first thing you’ll have to decide is whether you want to use solid fuel or propane.

Solid fuel can be coal, either butuminous or anthracite; metallurgical coke; or charcoal. There are forges that burn fuels like feed corn, wood, or wood pellets, but they are an insignificant percentage of available forges, and are more of a gimmick than a viable strategy.

Propane forges can be divided into two basic types; forced air forges, which require a fan or blower to operate, and atmospheric forges which do not. Forced air forge burners can be further subdivided into regular burners (which probably have a technical name, but not one I’ve heard) and ribbon burners.

Ultimately, if you really get involved in this you’ll want both a solid fuel forge and a propane forge, since each has strengths and weaknesses as compared to the other. Which type you should begin with will be determined by what best meets your needs for the type of work you plan to do.

Solid fuel forges all need an air delivery system to increase the temperature in the forge to heats high enough for forging. Forced air gas forges also need an air delivery system. It’s important to be able to deliver enough air without delivering too much.

You need to decide what type of forge to use, first. A coal/coke/charcoal forge can have either an electric blower, which can be as simple as a cheap hair dryer that has a ‘cool’ setting, or any number of squirrel cage blowers; or you can use a hand cranked blower, which though more labor intensive tends to be more fuel efficient.

For propane forges your choice will be an electric blower on a forced air forge, or an atmospheric burner which doesn’t need a blower.

SOMETHING TO FORGE WITH:

Something to forge with will be a suitable hammer. I recommend that as a beginner you start with a 2 pound hammer. Some will suggest heavier hammers, but that’s not a good idea when you’re first learning. It isn’t a question of whether you’re strong enough to swing it, but of whether you can make the hammer go precisely where you want it without injuring your arm or shoulder.

A 2 pound hammer will move material effectively, while letting you learn good hammer technique with minimal risk of tendonitis. If you’re small, completely unused to manual labor, or have limited endurance, an even lighter hammer might be a good plan. As you gain skill and muscle memory, you’ll be able to scale up to heavier hammers quickly with regular practice.

I recommend a cross pein hammer as being a useful configuration for a blacksmith, but a rounding hammer, a ball pein hammer, or a straight pein hammer will work fine.

When you get the hammer, you will want to ‘dress’ it, that is, smooth out any sharp edges it has so it doesn’t leave stray marks on your work. Marks like that are especially problematic if you’re making knives. Here is an example of a hammer as it comes from the supplier next to a dressed hammer.

 

 

There are several Youtube videos that offer information about good hammer technique. I have not reviewed them all, and can’t recommend for or against any of them. Here is one, however, that I suggest people watch to gain basic information and get ideas to work from. The most important takeaway is that if what you’re doing is hurting your wrist, elbow, or shoulder, STOP DOING IT before you do long term damage. Then study some more to figure out how to hammer without pain.

YOU’LL NEED SOMETHING TO FORGE ON:

Something to forge ON will be an anvil or anvil substitute. What you get will depend on your budget and the availability of suitable anvils in your area. Don’t get the fossilized mindset that your anvil MUST be of the traditional London Pattern (like you see Wiley Coyote dropping on the Roadrunner). A suitable substitute can be as simple as a block of steel from the scrapyard or the head from a sledgehammer, set on end in a stump.

YOU’LL NEED SOMETHING TO FORGE:

You’ll need something to forge, which would be steel or wrought iron. Some other metals are forgeable, but we’ll limit the current discussion to black metal.

Mild steel is readily available. I don’t recommend getting it from a box store like Lowe’s or Home Depot, because it’s hugely overpriced there. For what you pay for a four foot piece of steel at the box store you can buy a twenty foot piece at a steel supply company. But steel supply companies are abundant and widespread, selling to industries like construction, welding, and machine shops. If you have those industries in your area, you know you have a steel supplier that brings material to those shops. If you can’t buy from that supplier direct, maybe you can buy through one of those companies that already orders from them, or you may be able to buy leftover pieces (called ‘drops’) from jobs the welding or machine shop has done.

If you want to buy high carbon steel to make knives, online ordering is your best bet, but be prepared to pay ridiculous shipping costs. Your steel supplier may be able to order you high carbon steels, but will be unlikely to carry anything unless they specifically sell to knifemakers.

Whether your goal is making knives of cannister damascus, pattern welded steel, or mono-steel, keep in mind that not everything in your shop that you can scrounge is going to be good steel for knifemaking. Knives need a specific amount of carbon to be able to take and hold an edge. While you can forge about any steel to a knife shape, and make a sharp edge on it, modern knifemaking is defined by steels that will take a sharp edge and remain sharp for a long time as you work with it. Steels that will take a sharp edge but not hold it are considered inferior. Yes, historically many knives were made of steel or iron that no one would touch now. In their day, those were superior to whatever else was available. But these days are not those days.

There are lots steels that can be repurposed to make knives or tools; coil and leaf springs, various shafting material, etc., that may make serviceable tools. They can be excellent to learn to forge with, and can make durable, dependable tools and knives. The difficulty with using found steels is that you can never be certain what type of steel it is. Many people will say that “all springs are 5160”, but the truth is that “all” springs were never made of 5160. Manufacturers buy steel based on what has the best price and will meet the needs of the product being manufactured. That may mean the springs are made of 5160 for one model year, 1095 for the next model year, and 8630 the year after that, and you have no way of knowing or effectively finding out what it is. Without knowing what you have, you CAN’T know how to heat treat it to get maximum performance from whatever you’re making.

Additionally, if you’re using scavenged parts from automobiles or machinery, the steel has already had a service life that has exposed the steel to numerous stresses, like internal stress fractures, that may not show as you are forging a project, but may cause that project to fail after it’s made. If you are selling a knife made from a truck spring and it breaks, the person who bought it isn’t going to care that the spring had a micro-fracture from when it was on a truck. He’s only going to care that the handmade knife that he paid good money for just broke, and there goes your reputation as a knifemaker! THAT is why people so strongly recommend buying new, known steel to make knives or tools for sale; that way, you KNOW how to properly heat treat them because you KNOW what the steel is, and that it came with no hidden flaws from extended use.

YOU’LL NEED SOMETHING TO HOLD HOT STUFF THAT’S TOO SHORT TO HOLD WITH YOUR HANDS:

The last thing you’ll need is something to hold hot stuff that’s too short to have a cool end you can hang on to. For that you need tongs. Vise-grips and channel-lock pliers are a POOR substitute for real tongs. It’s easy for hot metal to slip out of vise grips or pliers and go flying. And trust me, few things can ruin your day like hot iron flying through the air.

Here are some good sources for blacksmithing supplies.

BLACKSMITH SUPPLY COMPANIES

In USA:

www.blacksmithsupply.com
www.quickanddirtytools.com
www.centaurforge.com
www.blacksmithsdepot.com
www.piehtoolco.com
www.kensironstore.com
www.gstongs.com
www.blacksmithed.com
www.texasfarriersupply.com
www.hammersource.com/blacksmithing-hammers/
www.farriersdepot.com/tongs.aspx
www.watersidemetalart.org/shop/
www.cloverdaleforge.com/blacksmith-tools-and-equipment-for-sale/

In CANADA:

www.pritchellandhardy.com/
www.canadianforge.com/
www.front-step-forge.myshopify.com/

In AUSTRALIA and NEW ZEALAND:

www.artisansupplies.com.au/?fbclid=IwAR1-xoKvDJ24-Kj0bqfKC4uKfZnqD45QxY3qLhFrWUraZXJllYAgx1fOAcY

In UNITED KINGDOM:

www.ebay.co.uk/usr/fishchipsandpeas?_trksid=p2047675.l2559&fbclid=IwAR1K7MHOtJyOXIp_UHJ4tEhelUYVa60aHqU1Qw6vQII6ueZTy4zPPseOrQM

FORGE BUILDING SUPPLIERS

IN THE USA:

Zoeller Forge
www.ZoellerForge.com

Iron Dungeon Forge
https://www.irondungeonforge.com/?fbclid=IwAR25V7CyNq0a7fZGdvFBzUP2Shu4hh4TDVrWxbmMXz6mF-XpEiuG5wvZC1c

High Temp Tools and Refractory
http://www.hightemptools.com/

Wayne Coe Artist Blacksmith
www.waynecoeartistblacksmith.com

Black Mutt Forge
https://www.instagram.com/Blackmuttforge

Hard Luck Forge and Supply
https://hard-luck-forge-supply.myshopify.com/

IN CANADA:

https://canadianforge.com/

IN THE UK:

VITCAS
https://www.vitcas.com/

IN AUSTRALIA AND NEW ZEALAND:

Gameco
https://www.artisansupplies.com.au/

 

One of the most important things for a beginner to understand

One of the most important things for a beginner to understand

One of the most important things for a beginner to understand is that blacksmithing is not an ‘instant gratification’ activity. It takes time and a lot of effort to become competent, and an incredibly large amount of practice to become skilled. But don’t despair! I am living proof that someone with no practical experience working with their hands can, given enough practice, become skilled at blacksmithing.

When I first began learning, my teacher Bob Patrick was kind and encouraging and gave me a solid foundation on which to build skills. That is probably the most important thing you should seek out when you’re first starting out. Books and videos are valuable resources to a beginner, but they are not ideal teaching tools because they lack nuance (do it THIS way, not THAT way…). As a beginner, you are not able to see subtle differences between the way a teacher, say, swings a hammer or angles a tool in a video, and the way you do it. But the teacher can give you that nuanced input. One of my role models for blacksmithing, Doug Hendrickson, once wrote me, “You’ll learn more in a week with a good teacher than you will in a year with a hammer in one hand and a book in the other.” Though a video may show a little more than a book, the same thing applies to them.

So get involved with the blacksmith association in your area. Almost every place in the USA and the more heavily populated parts of Canada has these organizations. Find good teachers, and soak them shamelessly for information. You’ll find them a sharing group of people.

“There is more than one right way to live.”
~ Daniel Quinn, author of Ishmael

“And if you don’t believe that, you’ll never find any of them.”
~ Walt Hull, artist-blacksmith