Sharpening Woodturning Tools - Doug Thompson

[Music] my name is Doug Thompson and we're gonna make this video today to show you the basics of grinding we're gonna show the house and more importantly the whys of grinding let me tell you about my background if you don't know me I worked at Ford Motor Company for 36 and a half years I was a machine repairman by trade I was in management most of the time and I took care of the maintenance of one-sixth of the plant that was three hundred and thirty thousand square feet of machines most of the time I was a flat wood worker and I used the lathe whenever I absolutely had to I started wood turning by chance I went to wood hat comm and saw Johannes Michaelson turn a hat you know like I couldn't believe that you could make one and what I did was call him up took his class and fell in love with wood turning okay.what turning was my life I'd go to work I turn wood I'd go to sleep and I'd wake up do the same thing again about eight years ago I was tired of the high cost of tools and decided to make my own tools why not I had a background in manufacturing so in my garage I have started making my own tools they worked out fine made out of good steel good heat treatment I was set for life I had tools for the rest of my life the only problem was I gave him away told my friends look look what I made so I gave them all away and all of a sudden I had to make more tools and my friends asked for different shapes different flutes and I said why not I could do it so I started manufacturing different tools I always used a bowl gouge but all of a sudden I was making spindle gouges and detail gouges and what started in my garage eight years ago for fun ended up being a business it hit the internet the internet with all the forums people all over the world reading them we started selling tools I didn't know if I wanted to make a business back then but I said yeah why not I'm ready to retire it'd be fun what I didn't know is how large it would get and the reason for doing this video is so you can learn how to sharpen buy sharpen every single tool that comes out of the Thompson lade tools I think it's real important and a sharp tool is a good tool to use [Music] okay now we're going to talk about grinders we use a standard 8 inch grinder that fits most of our jigs and everything like that I use a high speed grinder but I suggest use in a slow speed grinder it works just as well you'll remove less steel and it takes you longer to get in trouble let's face it the wheels I like to use our Norton 3 X K grade it's a 46 grit for roughing and then 80 grips for your finishing so when you're touching up your tools you're going to be using the 80 grit all the time when you're changing the grind you can use the 46 grit okay on wheels we have to dress the wheels let's face it the wheels clogged up with steel all the black marks you see in a wheel that's still embedded in the grain okay basically the way we do it most common way is a cluster diamond cluster diamond is just a bunch of little small diamonds held in a little holder here we turn the grinder on and we run it across the wheel the whole idea is to expose new grain all that steel that's embedded in the wheel don't worry about it just expose new grain to dress the wheel and make it look pretty again doesn't do any good it wastes money that you spent okay let me show you the two different ways we have a cluster diamond come across and just touch it and that's enough to expose the grain okay the other way is the Geiger single point diamond dresser I really like this comes with a single point diamond comes with a shoulder arrest against your platform and an adjustment knob to run this diamond in and out way it's done put your platform up here lock her down and you come up to the wheel and you're going to take this adjusting knob you put the shoulder against the platform and you run that diamond in till it just touches okay what happens here is you have a consistent distance between your platform and the end of the diamond the reason why you want to use a single point diamond dresser is you could make that wheel concentric to the spindle shaft so you have two spindle shaft here here's the outside of the wheel and that dimension between the spindle shaft and the outside will be the same between all these points okay if the wheel is concentric you will not have a grinder the vibrates there's no reason for it to vibrate you could balance the wheels everything else that's all you need is that single point diamond dresser and your grinder will run great ok grades a wheel let's talk about that if you start out at the letter A and go to the letter Z letter a is soft letter Z is very hard our range is between an eye and a K eyes are soft okay what happens is when you start grinding the tools the wheels gonna groove you know it's it's gonna fall apart easier you know we're a hard wheel resist set of grooving okay and it lasts a long time and that's what I suggest that's what I enjoy using [Music] well we sharpen the most misunderstood tool to get round right is the bowl gouge okay I'm going to show you a very easy way and the principles behind grinding a bowl gouge if you look at it we have a nose angle we have the convex curve we have the wing and we have the bottom of the flute okay we're going to start off with the nose angle the nose angle is 60 degrees why is it 60 degrees you know 60 degrees is not very sharp we sharpen an axe to 30 degrees but 60 degrees allows us to start at the rim of the bowl and follow through and one cut to the bottom of the bowl it's all clearance it's not sharp but for woodturning it works out just fine okay there's two different ways of sharpening you could do it freehand or you could use a jig the system I like is the one way Wolverine and the barek right this includes the two base units a V arm and a platform to the other thing you need with it is the bearer grind the bear grind can open it up gives us some instructions not very much you end up with this jig it's got a leg on it now what do you do I'm going to show you an easy way of setting this up so it's very repeatable it's very simple system to use very versatile ok so what I found out is you have to set the leg angle the leg angle is the most important thing okay and that sets the wing angle of a bowl gouge if the wings are too far in it doesn't cut well if the wings are too far out they don't hold up well I have a setting here that works out perfect okay it's very easy to use what you do is take your barrel grind put it right on the picture and set the leg angle now let me move down here set the leg angle you lock it down and never ever move it again this sets the wing angle of a bowl gouge and spindle gouges don't have wings so why move it doesn't matter where the legs at okay once we lock it down to make it repeatable we put the tool in now we have to set how much the tool extends out from the jig the whole idea with this is to make it consistent so we have the consistent leg angle and how much it extends out one way says an inch and 3/4 and that's what I use an inch and 3/4 from the end of the jig to the end of the tool I have a block here set at an inch and 3/4 I tighten it down and there we're all set to grind on the grinder you have this B arm that slides in and out and this such a nose angle now 60 degrees would be lower on the wheel your 40 degrees would be higher okay so we're looking for 60 degrees and that's going to be somewhere around there I'm going to lock it down turn the grinder on [Applause] make a little flat and we're going to check it okay I use a combination square okay the angle that we're actually checking is down the Fluke and across the nose so if you look at the board here it's down the flute down the flute and across the nose and this is going to be sixty degrees okay okay I can't see it there because I don't know if everything's right but I could come up here and I could put that nose angle against the stray edge and you can see that we're pretty doggone close I think I do this all the time okay so we have the nose angle [Applause] we're going to grind that to the very bottom of the flutes the next thing I'm going to show you is the secret to grinding bowl gouges okay any bowl gouge it doesn't matter if there's B shape you say parabolic this will show you how to grind the tool if I make a convex curve from the bottom of the flute to the top of the flute I'll show you how this works [Applause] [Music] [Applause] I created a convex curve from the top of the flute to the bottom of the flute this is going to give me an intersection from what I grow to the flutes if I grind the wings up to that intersection this bowl gouge will be grown properly okay do notice on this tube this is a V shaped bowl gouge and notice that intersection is parabolic okay that's what you want you want a very slight curve in your cutting edge some manufacturers line a parabolic flute which will give you more of a curve okay most of the professionals like this they want a very very slight parabolic line okay I'm going to grind the wing [Applause] they're like round one of the wings you could see how you're following that shape so they convex curved across the top of the tool will show you exactly how to grind it okay if you look at other tools we have our V shaped bowl gouge we have au shaped bowl gouge we actually have a spindle gouge all with that convex curve okay so the pattern that that curve creates is how you have to climb the tool the tool will be properly ground you can see the B shape it's got that slight parabolic you can see the U shape is get a very large radius at the nose and you can see the spindle gouge is also a large radius okay that's the secret with grinding bowl gouges spindle gouges it all works off that convex curve okay and now we're going to face up the grind so we have the rough line down there now okay so the next time you use the bowl gouge it starts to get dull all you have to do is barely cut it once across the grinder and you're set to continue on one thing I have to say is how much pressure do you use when you touch it up the edge and all you're doing is just take it a little bit of steel off one finger oppressors that's it one finger that's all you need and that's how to grind a bowl gouge [Music] okay right now we're going to describe the differences between a spindle gouge and a detail gouge the physical difference is you take a piece of steel and you cut a radius in it and say you cut a radius that's pretty deep say 50 percent what's going to happen on the edges it's gonna be as wide as the piece of steel that's a spindle gouge okay a detail gouge is got a shallower radius cut into it okay so therefore the flute is narrower and you also see on the sides there's an awful lot of Steel here it's got to be removed on a detail gouge you'll see that's why we put that fingernail on it is to remove all that extra steel on the side so we could create a radius across the nose now to climb them I started out with the beric rind extended out into three quarters come up to the grinder and you can see that the spindle gouge is just a radius okay a very large radius remember what we did with that convex curve okay that convex curve across the top created a very large radius and that's the intersection that we're going to glide to very simple turn the grinder on Macross hair is one sweeping motion we have the spindle gouge to grind the detail gouge because we have all that extra steel on the side we have to remove we have to create that fingernail okay generally a detail gouge is ground to more of a point this tool is made for coves and beads the grind it the fingernail will sweep back farther come back up and that's how the detail gouge is grown [Music] okay now we're gonna talk about scrapers okay scrapers are good they get you out of trouble that's they're easy to use but let's talk about the basic scraper and what it is okay you have a scraper this is a side view okay you have your nose angle is generally about 20 degrees it doesn't really matter get that range the sharper you make that nose angle the Gravier it's going to get so so about 20 degrees is fine what happens on a scraper is when that grinding wheel is coming across that piece of steel all this is ground away but this very top edge there's nothing to support it so what happens as you create a bird okay there's a little burr little piece of steel that rolls up and that's the cutting edge on a scraper okay what I do on my scrapers I'll take a piece of steel this is looking at the top I'll divide it in half the right-hand side I'll keep basically straight across and knock off this corner so it doesn't catch on the left-hand side I'll draw it down here to a little curve so your left-hand side you could do the inside of the bowl the right-hand side you could do that little nub inside of a bowl or the outside it gives you a lot of versatility to the tool okay let me show you how it's done now I have a very coarse wheel I'm going to grind the left-hand side to a radius and the right-hand side straight on this I'm going to push very hard then pull back push okay we come across we have the left hand side ground with a radius and the right hand side that's pretty much straight to grind this tool you're going to start on the left hand side here and come all the way around by doing that you're going to take this entire blind and move it straight down the tool so if you're using the left hand side only you are not going to grind that area you have to grind the whole the whole surface okay what we created here is a burr on that very top edge okay now that burr on this steel is good steel it's only going to last about 45 seconds in each area that you use it and after that you would go back and grind it again okay when you're talking about scrapers if you're parallel to the floor that's called a neutral rate if you raise your handle up it's a negative brake so when you're on the inside of a bowl or something like that raise your handle up a little bit okay it gives you a little better cut and you'll find what works for you okay there's some situations that you need a negative brake rather than raising your handle up you grind that into the tool here's the way it works you're taking that top surface and knocking the corner off okay and that is your negative brake so your burr will be down here now and that's gonna push up and when you grind this bottom section here you'll have a nice little bro that's gonna curl back okay if you're inside of a box or something like that that's when you really need it okay here's what we do now I have my platform and by the way that the platform I like is the Robo rest okay that's made by Reed gray and it's it's it's wonderful it holds the angle it's easy to use and I enjoy it turn the grinder on and notice I'm putting a lot of pressure on it and backing off and that creates your negative break [Music] now I'm going to show you a couple of tips and tricks sharpening it up ouch on this it's a bowl gouge if you look right here there's a dip right before the nose okay that's called a bird speech and what causes that is when you're rolling the tool between that radius at the nose and the wing you're going to hesitate and you're gonna grind too much off that area okay that bowl gouge will not cut well okay so we have to get rid of it and to get rid of it is real simple what I'm going to do is create a flat across the nose and then go through the standard grind I created my flat and now I'm gonna grind the pool like normal and the bird speak is gone the other thing if you ever have a high spot look at this side this has got a high spot right here I don't have to sweep across the entire grind to get rid of that I could just touch the tool in that one area take a little bit of steel off and get rid of it the whole idea with brining a tool is to take as little steel off as possible [Music] if you're ever at your friend's house and your bowl gouge needs to be sharpened and he's got his very grind and he says don't move my leg but you have to sharpen your tool what do you do there's a little trick and basically we're taking everything we'll learn before and reversing it okay so let's say is his legs out here okay no problem say we have that into three quarters before with us well like it doesn't matter where it's at okay we're going to set it there now you'll walk up to his grinder and rather than set the nose angle we're gonna set this V arm so the wing is flush with the wheel okay we'll take a little magic marker we're going to mark that bevel I'm gonna put it up here and we're going to slowly turn this wheel by hand can you see that right there okay you could see how that wheel is touching equally that line coming through there that we just ground off it's very straight that's what we're looking for okay so we know that we're we're pretty much on the wheel perfect now we're going to come up here and you can see we ground off all that magic marker we have a sharp tool it's really that simple so what basically we're laying the wings against the wheel rather than the nose against the wheel and that's the reverse ride [Music] now we're going to talk about steals and heat treatment we have different types of steals on the market some are from way back when and some are newer Steel's and let's let's go through them you have the common steal now it's an M - it's got another one it's m4 and let's see you have a 2030 you have a 2060 and you got a CPM 10b and a CPM 15b the difference between all these steals is how much vanadium they have in so you take the m2 that has two percent vanadium the m4 got four percent vanadium 20:30 has got five percent vanadium 2060 has got seven percent vanadium CPM ten B is got ten percent vanadium and 15 B is 15 percent vanadium okay so you can see the difference in them the better the steel the more Bonet diem it has in it except when you start coming up to the 15 B I make one tool out of that and it's a roughing tool it's a bowl gouge basically if you want a rough Bowl after Bowl after bowl it's got fifteen percent been 80 a minute it holds an edge good enough but there's a point where you get too much than 80 a minute where the the really sharp edge starts to break down this steel gets brittle okay so this one basically we're not going to talk about the 10 D it's a 10% all the rest of my tools are made out of this 10% vanadium steel and it's just absolutely wonderful it holds an edge longer than anybody else's because of that wear resistance and let's face it vanadium is in there just for wear resistance okay this steel is actually used in the industrial world for centerless grinders dyes stuck where it's it takes a lot of abuse and it holds up well okay let's talk about these Steel's most of these Steel's you'll see these are all imports you know and this one here the 10 B is made in the USA okay so it's real simple the more vanadium they have the longer the edge is going to hold these tools are made out of powdered metal okay let me explain the way standard steel is made they take all the elements and put it into a pot and they meld it and they pour it okay when you start getting the high percentages of an element the steel needs to be in a powdered form so those elements are dispersed evenly throughout the steel so basically that each element is run up a chute in a molten form the compressed air is blown it turns into little droplets and these little droplets are sifted out and sorted and when you have enough of each component to each element they're put into a mixer just like a mixer at home and then all that material after its next stop is poured into a form that form is heated just enough where the each element bonds together okay after that you'll take that that block of steel and start running it through rollers and that's how you get that powdered metal to a round state like this our tools are hardened tempered once with heat cryogenically treated that's where the steel is brought down to a minus 300 degrees and then tempered two more times with heat they spend about 50 hours in an oven about a half a day being frozen with the cryogenics I get a lot of questions about cryogenics exactly what it does for the steel cryogenics doesn't change the steel it just makes it better when you harden steel the steel becomes very very brittle okay and it you have to change it from a brittle state to a usable state okay and that's done by tempering when you temper a piece of steel with heat it changes the structure these again are tempered three times with heat but that second temper is done with cryogenics which is part of the tempering process with this steel cryogenics is basically working on freezing it's a deep freeze where they start out at room temperature and the steel is dropped down to a minus 300 degrees during this time there's changes inside of the steel the structure is changing okay and it could only be done with the cryogenics [Music] you [Music]

Channel: Thompson Lathe Tools

Views: 207,234

Keywords: Thompson, thompson lathe tools, doug thompson, grinding, gouge, bowl gouges, spindle gouge, scraper, woodturning, woodturning tools, wolverine, ellsworh grind, tormek, cbn wheel, oneway, varigrind, vari grind, robo rest

Id: ttYyulsM7wg

Length: 38min 38sec (2318 seconds)

Published: Fri Jul 24 2015