# Be careful what you read.



## Steve Neul (Sep 2, 2011)

I found this on another forum: I've read in several places including old manuals of Delta's that one way to sharpen jointer blades is to "joint" them with a stone while the head is turning. This is done by placing a stone on the out feed table and gently advancing over the head. This sharpens the blades and ensures exact height of all blades. Now this still sounds quite scarry to me. Has anyone done this and if so what grit of stone?

Gees, I had to read it twice to believe what I was seeing.


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## epicfail48 (Mar 27, 2014)

That sounds like a horrible idea. I vaguely remember seeing some machines with a system like that built in, with a stone built into a carriage mechanism, and ive heard they work pretty well, but going at it freehand sounds like a great way to get people to start calling you stumpy


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## difalkner (Nov 27, 2011)

Nobody that has done that can type with their fingers now, Steve...


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## Steve Neul (Sep 2, 2011)

epicfail48 said:


> That sounds like a horrible idea. I vaguely remember seeing some machines with a system like that built in, with a stone built into a carriage mechanism, and ive heard they work pretty well, but going at it freehand sounds like a great way to get people to start calling you stumpy


There is a grinding attachment that fits on some jointers that you can grind and hone the knives without taking them off. I think this may be what this guy is confused about.


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## woodnthings (Jan 24, 2009)

*I had read it also*

This may be the forum you are referring to:
http://www.woodweb.com/knowledge_base/Sharpening_Jointer_Knives_on_the_Machine.html


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## Steve Neul (Sep 2, 2011)

woodnthings said:


> This may be the forum you are referring to:
> http://www.woodweb.com/knowledge_base/Sharpening_Jointer_Knives_on_the_Machine.html


Same message, different channel. Someone has their wires crossed. Common sense would tell you a sharpening stone would round the edge off the knives.


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## woodnthings (Jan 24, 2009)

*accoprding to thosse who did it...*



Steve Neul said:


> Same message, different channel. Someone has their wires crossed. Common sense would tell you a sharpening stone would round the edge off the knives.


It's a pretty good discussion in the link.

They reported the operation creates either a micro bevel or a flat, not sure which one, but the flat caused the knives to knock against the work making the sound louder. 

I could see using a reversed belt and running the cutter head in reverse and how that may be more successful, I donno?


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## Steve Neul (Sep 2, 2011)

woodnthings said:


> It's a pretty good discussion in the link.
> 
> They reported the operation creates either a micro bevel or a flat, not sure which one, but the flat caused the knives to knock against the work making the sound louder.
> 
> I could see using a reversed belt and running the cutter head in reverse and how that may be more successful, I donno?


It just seems to me it would be like hitting a nail even running it backwards. An actual joining attachment would work the stone parallel with the head holding the grind angle just taking the bur off from grinding.


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## epicfail48 (Mar 27, 2014)

Once you get past the "oh my god, why would you do that" part, the sharpening effect actually does make sense. Sort of. You'd get a concave grind, which is durable but generally not the sharpest grind. So, a mild improvement over dull, but still, I would do it


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## BigJim (Sep 2, 2008)

Not this ole boy, :no: just thinking about that sends chills up my spine.


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## hwebb99 (Nov 27, 2012)

I have read of honing the blades in the jointer with the jointer off. If you try it running, you might as well trim your finger nails while you're at it.


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## ryan50hrl (Jun 30, 2012)

yeah....I'm going to take mine out.....


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## GeorgeC (Jul 30, 2008)

Steve Neul said:


> I found this on another forum: I've read in several places including old manuals of Delta's that one way to sharpen jointer blades is to "joint" them with a stone while the head is turning. This is done by placing a stone on the out feed table and gently advancing over the head. This sharpens the blades and ensures exact height of all blades. Now this still sounds quite scarry to me. Has anyone done this and if so what grit of stone?
> 
> Gees, I had to read it twice to believe what I was seeing.


I am thinking of using that procedure. I am in the process of building a robot that can manage the entire process so that my body is in another room.

George


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## d_slat (Apr 10, 2012)

epicfail48 said:


> You'd get a concave grind


I was thinking it would end it would be convex. Either way, I think I'll pass on this operation.


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## hwebb99 (Nov 27, 2012)

I think it would be convex, but I am still going to pass.


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## epicfail48 (Mar 27, 2014)

hwebb99 said:


> I think it would be convex, but I am still going to pass.


Yup, you're right. For some reason I can never get concave and convex right the first time


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## Tman1 (Jan 14, 2013)

epicfail48 said:


> Yup, you're right. For some reason I can never get concave and convex right the first time


The trick is to remember that concave is like a cave.


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## woodnthings (Jan 24, 2009)

*nope*



epicfail48 said:


> * You'd get a concave grind, which is durable but generally not the sharpest *grind. So, a mild improvement over dull, but still, I would (NOT) do it


If you hold a stone on the tables located flush with the tips of the blades all you will do is reduce the amount of the tip either making a micro bevel or flatten out the bevel. You will not end up with a concave or hollow ground blade.

Like this:


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## epicfail48 (Mar 27, 2014)

woodnthings said:


> If you hold a stone on the tables located flush with the tips of the blades all you will do is reduce the amount of the tip either making a micro bevel or flatten out the bevel. You will not end up with a concave or hollow ground blade.
> 
> Like this:


I agree that its a microbevel and not a full grind, but the microbevel is still taking on the arc of the blade path, giving a convex grind

I should also mention that I'm referring to the "stick the stone on it with the power on" method Steve posted about. If the power is off and one is just honing the blades in place, itll result in a flat grind


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## firehawkmph (Apr 26, 2008)

Sounds like an old wife's tale to me. There is no way that would result in a sharp knife. Never seizes to amaze me what comes across the Internet. Take them out and do it right. 
Mike Hawkins


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## the dude (Jun 15, 2012)

I actually tried this on an old 4 inch delta jointer I got from my grandfathers shop. The process is in the manual that came with the machine. I believe they called it "whetting" the knives .not really a scary process at all, the knives just barely kiss the stone and really with s longer stone like I used my hands were a good couple inches from knives and When I did it I felt no kind of force that scared me, it wasn't like it was trying to rip the stone away from me. Doing so made that old machine cut like a dream compared to before I did it when knives were dull. Delta has been making jointers for a long time and if they put it in the manual I don't think its that crazy and it did work with no I'll affect.


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## BWSmith (Aug 24, 2010)

We don't use this method so the following comments aren't pro or con.There's two things that quickly pop into my pea brain,again.....just an observation.

They are;the first is how you are effecting the shape of the edge vs taking them off and grinding(which can be either hollow ground or not,think surface grinder).If,ya'll are discussing rotating the head vs stoning in a stationary or non rotating mode.Because that'll make a difference in the profile.Got to throw in "practical" here vs theory.

The second is that;sort of irrespective of how well one is at "setting" knife heights(within reason,we're talkin .001's here,not a quarter of an inch,haha)....this action will result in a higher degree of accuracy because you're "lathe" turning the knives,in situ.


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## the dude (Jun 15, 2012)

I will admit I was alittle skeptical when I saw it it manual but figured if delta put it in there then must be something to it and the knives in that machine were pretty bad so I figured I had nothing to lose. And like I said it worked just fine. It just kills me when people are so adamant that there is no way that would work and that its crazy or isn't true without researching it at all. I wish I still had manual so I could read up on it again.


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## woodnthings (Jan 24, 2009)

*see signature below*



the dude said:


> I will admit I was alittle skeptical when I saw it it manual but figured if delta put it in there then must be something to it and the knives in that machine were pretty bad so I figured I had nothing to lose. *And like I said it worked just fine.* *It just kills me when people are so adamant that there is no way that would work and that its crazy or isn't true without researching it at all.* I wish I still had manual so I could read up on it again.



If you haven't done it, how can you give advice either pro or con? :blink:

A good method for creating a micro bevel.... jointer not under power.

https://www.youtube.com/watch?v=nSNUn4LLsmI


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## the dude (Jun 15, 2012)

woodnthings said:


> If you haven't done it, how can you give advice either pro or con? :blink: A good method for creating a micro bevel.... jointer not under power. https://www.youtube.com/watch?v=nSNUn4LLsmI


 I'm alittle bit confused, I have tried it. See a few posts above. Or maybe I'm missing something or misunderstanding since you quoted me I got the feeling you were thinking I never tried it


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## the dude (Jun 15, 2012)

I have never tried the method in the video tho and that looks like another good option. I did it while cutter head was turning


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## woodnthings (Jan 24, 2009)

*No, not meant for you*



the dude said:


> I'm a little bit confused, I have tried it. See a few posts above. Or maybe I'm missing something or misunderstanding since you quoted me I got the feeling you were thinking I never tried it


That's why I used bold print in the quote. Others haven't tried it yet were adamant it either wouldn't work or be very dangerous. You did it with success.


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## the dude (Jun 15, 2012)

woodnthings said:


> That's why I used bold print in the quote. Others haven't tried it yet were adamant it either wouldn't work or be very dangerous. You did it with success.


 oh lol I totally missed the bold print. I figured I was misreading


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## woodnthings (Jan 24, 2009)

*giving this more thought*

You can place your stone on either the outfeed or infeed table. 

The difference is the rotation would be "into" the stone on the outfeed and "away" from the stone on the infeed table. The result may be similar, I donno? It would seem "safer" with the stone on the infeed table, since rotation would not jamb the stone, just tend to carry it away. 

I wish someone had the instructions ..... :yes:


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## FrankC (Aug 24, 2012)

woodnthings said:


> You can place your stone on either the outfeed or infeed table.
> 
> The difference is the rotation would be "into" the stone on the outfeed and "away" from the stone on the infeed table. The result may be similar, I donno? It would seem "safer" with the stone on the infeed table, since rotation would not jamb the stone, just tend to carry it away.
> 
> I wish someone had the instructions ..... :yes:


Wouldn't the idea be to level the knives with the outfeed table?


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## woodnthings (Jan 24, 2009)

*I donno?*



woodnthings said:


> You can place your stone on either the outfeed or infeed table.
> 
> The difference is the rotation would be "into" the stone on the outfeed and "away" from the stone on the infeed table. The result may be similar, I donno?* It would seem "safer" with the stone on the infeed table, since rotation would not jamb the stone, just tend to carry it away. *
> 
> I wish someone had the instructions ..... :yes:





FrankC said:


> Wouldn't the idea be to level the knives with the outfeed table?



On most jointers both tables are adjustable, so either could be used. JMO

The process would have 2 functions, one is to make all the knives the same height within reason or "leveling." We are not talking major misalignment, only thousands or fractions of there of.

The other function is a byproduct of the first, which of course is sharpening the knives, or creating a micro bevel. 

Probably some experimentation would be in order. If this process really works well, and can be done safely, it would be a great way to refresh the blades mid project without down time. If the process has been "discontinued" by removal from owner's manuals because of liability reasons rather than practical reasons, that would be good to know. :yes:

IF I were to attempt it, I would use my diamond impregnated steel stones rather than a oil or water stone, which may fracture..... The issue I see is that on some infeed tables with levers rather than wheels, the height adjustment is not all that precise. You would want to make several dry runs "without power on" to get the height just perfect. Also I would probably also use a very strong magnet to hold the stone, since it would work well on the steel and cast iron table. Another issue is the stone should be slid across the entire width of the knives, this would be difficult unless done by hand, which raises safety concerns. This is why I suggested using the infeed rather than the outfeed table above.

Lots of things to consider here. :yes:


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## Tman1 (Jan 14, 2013)

woodnthings said:


> You can place your stone on either the outfeed or infeed table.  The difference is the rotation would be "into" the stone on the outfeed and "away" from the stone on the infeed table. The result may be similar, I donno? It would seem "safer" with the stone on the infeed table, since rotation would not jamb the stone, just tend to carry it away. I wish someone had the instructions ..... :yes:


Or, taking it one step further, you could put it across both tables. You just need to make sure the infeed is the same height as the outfeed tabl. Which you would need to anyway if you were using the infeed. This seems like it would give the most control since you would have solid support on both sides of the cutters.


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## the dude (Jun 15, 2012)

The main reason I have not done this again in the jointer I have now is because I no longer have the manual for other machine and can't remember exactly the procedure. I know for sure I used the out feed table and I think I raised the table above the knives, laid stone on table with enough hanging over to hit the knives. Turned machine on and with one hand applied pressure to stone to hold it down to table then slowly lowers table till knives just barely kissed the stone then slid stone across the table to hit entire length of knife. That was basically it I believe. Maybe lowered it again a few thousands after the they were all "leveled" to each other. I do not believe this process was intended to totally regrind a very dull or damaged knife, just more of s way to "dress" then and put alittle more life in them. I will say that I do believe that that is the process but since I no longer have the manual please don't quote me on this.


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## the dude (Jun 15, 2012)

https://www.oellasawandtool.com/Oella Saw PDF Library/37-110.pdf ok I don't know if this link will work but I found manual online. There are actually two processes listed. One is "whetting" the knives and that is actually done while not under power and the other is "jointing" the knives which is done under power. It had been awhile so I got the terms mixed up in earlier post.


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## FrankC (Aug 24, 2012)

the dude said:


> https://www.oellasawandtool.com/Oella Saw PDF Library/37-110.pdf ok I don't know if this link will work but I found manual online. There are actually two processes listed. One is "whetting" the knives and that is actually done while not under power and the other is "jointing" the knives which is done under power. It had been awhile so I got the terms mixed up in earlier post.


That explains it in a nutshell.


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## WarnerConstInc. (Nov 25, 2008)

It used to be a very common practice to joint the knives on you jointer like this.

It's the same concept and using the jointing stone on the grinding rig on big planers.

It does put a slight bevel on the knife tips, it also ensures the knives are in a perfect circle to each other.

It is not really hard to do, the machine is not going to pull your stone and hand into it. 

I swore there was a youtube video of this being done, but no time to look now.

It is a good way to get a fresh edge an extend the time between knife changes and grinds.


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## WillemJM (Aug 18, 2011)

This use to be standard protocol in large manufacturing shops among the old-timers. It was not done by hand though, the jointers had a fixture allowing grinding the knives this way.

Today things are different, most of the larger factories use a different type of knife for high volume production.


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## woodnthings (Jan 24, 2009)

*how so?*

I've heard of a planer sharpening fixture that travels along the blades. Not heard of one for use on a jointer, but would not be surprised if there was one.... too large to do any other way and too much down time, too costly to do otherwise...I donno?

Can you explain what you meant in the above by "fixture"? Did it hold a stone? Did it travel? :blink:


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## WarnerConstInc. (Nov 25, 2008)

WillemJM said:


> This use to be standard protocol in large manufacturing shops among the old-timers. It was not done by hand though, the jointers had a fixture allowing grinding the knives this way.
> 
> Today things are different, most of the larger factories use a different type of knife for high volume production.



Jointers were stoned by hand, that way the knives were perfect to the outfeed table.

Some bigger jointers had sharpening rigs just like the bigger planers had.



Bill- Whetting was done with the machine off and was nothing more then a quick hand pass across the knives, not even really sure it is necessary.


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