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Question about Thompson tools

Tony, I have several of Doug Thompson's tools; 6 bowl gouges which are the HannesTools - (Doug supplies JoHannes Michelsen with the steel for his tools) detail gouges and skews. I've had some of them for quite awhile now, and I have never lost the temper of any of his tools from sharpening.

You simply can't find a better tool, in my opinion, than what Doug Thompson makes.
 
I think it would be impossible to remove the temper using a grinder. You might get them red hot but the heat treating temperature for these tools is way above that. I have almost quit using my other tools since I got the Thompson tools. I just like the way they cut and handle.
 
Thompson Tools - Grinding Abuse

A word of caution.

While HSS and other highly alloyed tool steels like CPM 10V (A11) resist abusive grinding, compared to High Carbon tool steels, they still can be damaged quickly and easily.

Two temperatures are important to consider when grinding tools made from HSS as well as CPM 10V (A11) - the critical temperature (approx. 1550F): above which the steel will begin to reharden and become briittle; and the tempering temperature (about 1025F) above which the fully heat treated steel will soften or "temper back".

At 1025F the steel is barely showing a very dull red color in a darkened room. In your shop, you can easily exceed it and not see it with the lights on. If you see deep blue/gray color around the ground edge - you have exceeded it!

In excess of 1550F, the edge will be medium to bright orange during grinding. If you see a bright edge while grinding, you are way too aggressive. As most are aware, you can very quickly achieve very bright colors on the edge, if not careful.

It is very easy to damage tools made from the highest alloy highspeed and tool steels by grinding. If you take the time and care to grind them properly, they wear for a long time. This why I am a proponent of grind a little, hone a lot.

For detailed information on specific grades as well as advice on grinding wheels, etc. look up www.crucibleservice.com/eselector


Jerry Wright
 
Over the last 10-12 years, I have sharpened most every brand of tool on the market at one time or another on a lot of different wheels. I've never been "easy" on the grind and not once have I ever had a problem with the steel no matter what kind it was. IMHO, this whole grinding thing is nothing more than a distraction from turning. If your tool is dull, sharpen it and get back to turning. You'll learn what works best for you over time.
 
I keep a plastic coffee can full of H2o beside the grinder, and when I need to grind continually on any portion of a tool surface.....I use it. Likewise, grinding has the same rules that apply to sanding.......keep it moving! 😀

I don't believe I've ever had HSS lose it's temper, but I've got some older carbon steel tools that I watch very carefully when I grind. I suppose if I ever had lost temper, I'd know for sure......and since I don't, that's a good sign! :cool2: In all things grinding, paying attention, and not allowing "tunnel vision" to cloud the overall picture is key.

Question: Can the temper be lost without the telltale discoloration?

OOC
 
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Three additional comments:

If you see no discoloration, you probaby have not affected the temper. Just remember that the affected zone can be < .001", and you may not see it. Remember that the steel always knows!

If a turner has never damaged a tool by grinding, several things are in play. 1) a life long, wonderful combination of grinding wheels, rpm, and touch; or 2)lack of awareness of how quickly tools are dulling after grinding, or 3)amazing patience.

I have never seen a turner, who is turning, not have fun. Sharpening interferes with turning, but is a necessary evil. Done properly, you have to do a lot less of it.

Jerry
 
odie said:
I keep a plastic coffee can full of H2o beside the grinder, and when I need to grind continually on any portion of a tool surface.....I use it. Likewise, grinding has the same rules that apply to sanding.......keep it moving! 😀

I don't believe I've ever had HSS lose it's temper, but I've got some older carbon steel tools that I watch very carefully when I grind. I suppose if I ever had lost temper, I'd know for sure......and since I don't, that's a good sign! :cool2: In all things grinding, paying attention, and not allowing "tunnel vision" to cloud the overall picture is key.

Question: Can the temper be lost without the telltale discoloration?

OOC
Click to expand...

Again there's mention of water which I assume is there for cooling hot tools. The reason one shouldn't dip HSS tools is very fine cracks form along the edge. These are not visible but do affect how long the edge lasts.

Malcolm Smith.
 
Malcolm Smith said:
Again there's mention of water which I assume is there for cooling hot tools. The reason one shouldn't dip HSS tools is very fine cracks form along the edge. These are not visible but do affect how long the edge lasts.

Malcolm Smith.
Click to expand...

Hi Malcolm......

Interesting.......I'll have to admit not being aware of that.

Is there anywhere I can see close up photos of these cracks? Do they form under all conditions?.....all heat ranges?....all HSS? or, under specific conditions, heat ranges, and steels?

I may have to modify my habits, but for the record, I seldom have to quench any of my HSS tools. The times that I do are usually when shaping a profile shape.....almost never for edge sharpening, because it's done so quickly. Do you feel the sharpened edge cracks can occur from heating at a previous time, and not by sharpening the edge?

otis of cologne
 
A well dressed wheel won't burn and use the right wheel for what your doing. To change the grind stick with a 46-60 grit wheel, even a gray wheel will work for this now to touch up an edge the higher grits are better. I have tried to burn the steel and it's almost impossible with a dressed wheel but when the wheel needs to be dressed it happens very easy. To cool a hot piece of steel lay it on another piece of steel, some how the heat is transfered.
 
odie said:
Hi Malcolm......

Interesting.......I'll have to admit not being aware of that.

Is there anywhere I can see close up photos of these cracks? Do they form under all conditions?.....all heat ranges?....all HSS? or, under specific conditions, heat ranges, and steels?

I may have to modify my habits, but for the record, I seldom have to quench any of my HSS tools. The times that I do are usually when shaping a profile shape.....almost never for edge sharpening, because it's done so quickly. Do you feel the sharpened edge cracks can occur from heating at a previous time, and not by sharpening the edge?

otis of cologne
Click to expand...

I mostly sharpen with a Tormek but do have a couple of grinders, mainly for making changes to new tools. It's possible that the cracks can be seen with a microscope. I don't know. Not wetting tools is a commonly encountered piece of advice which usually refers specifically to HS steel This would seem to make sense as softer steels would probably have enough give to avoid cracking. Back when tools were all regular steel they were cooled with water but in truth, it only took about 300 degrees to damage the steel. One wouldn't know it, and would simply sharpen frequently.

The stones that come on a new grinder should immediately be replaced with better stones which can be used with a lot less heat being generated. With a light touch, they work very well and won't heat the steel as much.

The type of tool is another factor. Scrapers are less likely to suffer damage as there is more metal at the edge to allow the heat to disipate.

The danger to one's tools is one of the reasons I use a Tormek but there are many ways to sharpen tools. Most people use a high speed grinder. Nearly all my tools are vanadium steel which does not need to be sharpened often.

Only other suggestion is wear dust protection. Dust from the wheels obviously remains in one's lungs for a long time.

Malcolm Smith.
 
Doug Thompson said:
A well dressed wheel won't burn and use the right wheel for what your doing. To change the grind stick with a 46-60 grit wheel, even a gray wheel will work for this now to touch up an edge the higher grits are better. I have tried to burn the steel and it's almost impossible with a dressed wheel but when the wheel needs to be dressed it happens very easy. To cool a hot piece of steel lay it on another piece of steel, some how the heat is transfered.
Click to expand...

Malcolm Smith said:
I mostly sharpen with a Tormek but do have a couple of grinders, mainly for making changes to new tools. It's possible that the cracks can be seen with a microscope. I don't know. Not wetting tools is a commonly encountered piece of advice which usually refers specifically to HS steel This would seem to make sense as softer steels would probably have enough give to avoid cracking. Back when tools were all regular steel they were cooled with water but in truth, it only took about 300 degrees to damage the steel. One wouldn't know it, and would simply sharpen frequently.

The stones that come on a new grinder should immediately be replaced with better stones which can be used with a lot less heat being generated. With a light touch, they work very well and won't heat the steel as much.

The type of tool is another factor. Scrapers are less likely to suffer damage as there is more metal at the edge to allow the heat to disipate.

The danger to one's tools is one of the reasons I use a Tormek but there are many ways to sharpen tools. Most people use a high speed grinder. Nearly all my tools are vanadium steel which does not need to be sharpened often.

Only other suggestion is wear dust protection. Dust from the wheels obviously remains in one's lungs for a long time.

Malcolm Smith.
Click to expand...

I tend to agree with Doug Thompson that for most practical purposes, a lathe turner will probably not ever lose the temper on his HSS tools.......but, I'm listening carefully to what Malcolm Smith has to say, as well. He seems pretty sure of the cracking issue he speaks of.......and I'm admittedly not absolutely sure what is correct, or not correct. It sure seems like 300oF is a low amount of heat to cause damage to the steel.....and I'm wondering if it applies to the whole spectrum of HSS.....? I'm also wondering if it ONLY applies when quenching in water.......which I've explained in a previous post that I seldom, if ever do when sharpening an edge.

Anyone else have a comment on this?

OOC
 
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Water won't hurt HSS. It is made to be used in machining/manufacturing, is commonly cooled with water/oil emulsions, and is measured by such factors as "red heat hardness"

If one is bluing the edge, it means that something needs to be done differently, as has been pointed out.

Like Sean said, sharpen the thing and get back to turning. FWIW, if one was to sharpen the tool by some good method, no matter what it's made of, after every cut, that person's turning would improve.😀

John
 
Never had problem with HSS

I have not had a problem with any of my HSS tools, just always aused a light louch and learned right off the bat that if a tool gets to the point that it NEEDS sharpening you waited too long. My mentor taught me a light touch up every now and then is alot better than a heavy sharpening at anytime. I just wasn't sure about these as i have only had sorby's up till now. BTW i have to say i emailed doug thompson right after i posted the question on here and had an answer from him the next morning. It really is nice to be able to know if i have a question that i will get an answer rather than getting the run around from a customer no-service.
 
Doug is one of the nicest guys you'll meet. I've turned with his tools and they are the finest. Now if I can just wear down all the gouges I have, I can finally order some of his. I think the sharpening question brings up a good point and that is so many turners take up so much time trying to learn everything about the tools, metals, machines, finishes, embellishments etc... that they never spend enough time practicing turning and don't improve their skill level as much as they could. My thought is, let the the manufacturers worry about the products we use and spend as much time turning with these products as we can.
 
Sean,
Do what I did, put your old tools on the raffle table at your club or give them to the new turners in your club. A bunch of good deeds that allowed me to get more Thompson tools!😀
 
Thompson Tools

I had the pleasure of meeting Doug at the PDX AAW symposium. I picked up a couple of his bowl gouges then and have purchased a couple more sense. They are great tools, reasonably priced and they take and hold a great edge. For me, these are my favorites, right up there with my 2 mastercut gouges.

Tools just seem to follow me home, especially good ones.
 
Tony, I run the size from 0 to -.003 on the shanks so the same size drill bit would be a very tight fit. Metal handles are bored oversize about .006 then glued in place, (0 into 0 won't fit) if you plan to use set screws you can go .015 oversize or more with out any problems. Do let me know if there are any problems, we'll figure them out.
 
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