How to hone round nose NRS

[Raif Harik]

Hi, as I am trying to master/understand my new veritas burr tool, I have been advised ( here ) to hone the grinder burr off and then bend a new one with the burr tool. give or take some details. While I have understood the part about getting as clean a point between the two bevels, I find it very hard to do on my french curve(ish) NRS. I'm wondering if there is a nifty trick to this, or a tool, or something. Any advise would be helpful.
Thanks

 

[John K Jordan]

Hi, as I am trying to master/understand my new veritas burr tool, I have been advised ( here ) to hone the grinder burr off and then bend a new one with the burr tool. give or take some details. While I have understood the part about getting as clean a point between the two bevels, I find it very hard to do on my french curve(ish) NRS. I'm wondering if there is a nifty trick to this, or a tool, or something. Any advise would be helpful.
Thanks

I'm not sure what you mean by "french curve(ish) NRS". Is this something you ground yourself or bought? What does it look like from the side - sharpened like a skew or shallow angle on top, steeper angle below, curved on one edge? Please post a photo of your NRS, top and side views.

I remove the grinding burr from NRS occasionally by stropping on the flat leather wheel on a Tormek (with some honing compound applied)

However for NRS , I most often remove the grind burr with very light honing with an extra fine Eze-Lap diamond "paddle" hone (the blue one) or a ceramic hone. With the hones, I press the hone lightly between the edge with the burr and the heel of the bevel and make a gentle, smooth sweep along the edge. Shouldn't take more than one sweep. Don't raise the back side of the hone to put more angle/force on the scraping edge. You can feel for the grinding burr to assure it's all removed.

After removing the burr, I create a new burr from the bottom side with a hand-held burnisher. Doesn't take much pressure. The burr should be easy to feel with the finger/fingernail.

For card scrapers, curved or straight, I remove the grinding or sharpening burr with the same extra fine diamond diamond hone by holding it flat against the side of the scraper. Then burnish a burr.

I grind and often use curved NRS, but I'm not sure I would call them french curves. In fact, I don't think I've ever heard of a "french curve" NRS.


Hey, you don't mean the kind of curved card scraper on the left of this picture, do you? I've never sharpened a card scraper as NRS. (An NRS can't be flimsy for use on the lathe.)


For those, I usually cut the end off with a Dremel to make a small card scraper held between two fingers.


The whole NRS/card scraper thing could use a good document or video. I simply wouldn't know how to work effectively without them.

JKJ

 

[John K Jordan]

BTW, the blue EZE Lap diamond hone here is the one I use 90% of the time in the shop. I occasionally use the coarser red one when sharpening the edges of flat or curved cabinet/hand scrapers. I've tried MANY types of diamond hones over the years and this is the only type I'll use with lathe tools. I put my hold the handle in the curl of my fingers and steady behind the honing part with the forefinger of the same hand. Extremely easy to control that way.



I like these so much, years ago I contacted EZE-Lap directly and ordered a lifetime supply!

JKJ

 

[Raif Harik]

Well, I was just watching a video by Glen Lucas about the tools he sells and he referred to one that was similar to one I had as a "french curve" scraper. Now that you bring it up, I seem to remember a french curve being more like that one card you have pictured above. But what do I know. In any case my scraper looks like the three curved NRS' you have pictured above.
I have attempted to do as you describe with a little diamond card. It's just difficult around the nose of the scraper. With all the talk of perfect point and looking with a microscope I just felt that what I was probably doing more harm that good. I guess it's a matter of getting the muscle memory down.

 

[John K Jordan]

I have attempted to do as you describe with a little diamond card. It's just difficult around the nose of the scraper.

I got used to lightly resting the hone on the bevel supported by both the sharpened edge and the heel of the bevel, then "feeling" with my forefinger to keep it firm against both as I move the hone around the curve. Maybe I can take a picture if that might help. You only have to hone the "top" side, of course.

I've heard those curved card scrapers referred to as "gooseneck" but I don't know what the real name is. I find them fairly worthless for woodturning so I cut them in two and make one small one and one big teardrop scraper. Most of the card scrapers I use are simple curves of various radii and ground on the four sides of a rectangular card scraper. One is what was left when I cut the end off a gooseneck one then shaped it a bit more. BTW, I find the best way to shape card scrapers is not with a grinder, but with a belt sander. I do, however, use a CBN wheel (600 grit) with the platform set to 90-deg to make the edges smooth and perpendicular.

The two scrapers in the upper left are Stewart-McDonald scrapers, 1/8" thick, sharpened an entirely different way, no burnished burr, sold to people who make violins, cellos, and guitars - they are very good (but not cheap).


One curved hand scraper in use - they smooth so well I can usually start with 600 or 400 grit), sanding by hand.


Before that stage, I use the NRS to remove tool marks from the gouge:



JKJ

 

[Odie]

Well, I was just watching a video by Glen Lucas about the tools he sells and he referred to one that was similar to one I had as a "french curve" scraper. Now that you bring it up, I seem to remember a french curve being more like that one card you have pictured above. But what do I know. In any case my scraper looks like the three curved NRS' you have pictured above.
I have attempted to do as you describe with a little diamond card. It's just difficult around the nose of the scraper. With all the talk of perfect point and looking with a microscope I just felt that what I was probably doing more harm that good. I guess it's a matter of getting the muscle memory down.

I don't completely understand what is being referred to as a "French curve" on a NRS. The only time I've been associated with the term is way back in a high school drafting class.

As @John K Jordan mentioned, it takes a very light pressure of a diamond hone to remove the ground burr on a scraper.....very light. When I first started using diamond hones, I used too much pressure, and I suspect quite a few turners and woodworkers do at first. As he stated, you can use your finger to determine the top surface is completely flat. After using the diamond hone, the ground burr can and will otherwise be so insignificant that your eyes will deceive you.

The very tip of the cutting edge for a raised burr is the result of how well the diamond hone creates it. The burnisher merely bends it up into a more useful configuration for turners. A circular motion works well, but a crisscross direction from the edge backwards seems to result in the best cutting edge overall. (Both will work, and I use both......the crisscross method for scrapers, and the circular method works better for gouges......not because the cutting edge is better, but because of it's convenience in producing the edge.)

When forming a burr on the Veritas burnisher tool, the reason there is a fulcrum post, is so there is an ability to leverage a much stronger pressure in forming the burr. The more the pressure, the stronger the burr will be. You need to experiment with this to see just how much pressure gives you the most useful burr. For myself, the best burr isn't the most extreme burr that is possible.....but, rather somewhere in the middle. A very light burr, similar to that a hand held burnisher will give, IMHO doesn't give the most effective burr......and this is why the Veritas burnisher was invented.

Now that you have the Veritas burnisher, you can create a much wider spectrum of useful possibilities. With time and experimentation, you'll find what works just right for you.

For those who are following this thread, this photo is of the Veritas burnisher tool we're discussing:


=o=

 

[John K Jordan]

For those who are following this thread, this photo is of the Veritas burnisher tool we're discussing:

I have one of those (haven't used it for years). Good for large conventional scrapers but I can't imagine using one on a negative rake scraper, at least one ground a bit like a skew with small included angle. I think I missed the part about using a Veritas! I use only a hand-held burnisher (love the Arno).

When I burnish a negative rake scraper it is usually with a gentle force and at an angle that closely follows the lower bevel, but with small angle between the burnisher and the bevel. To much burr can make the NRS harder to use gracefully.

And yikes, beside the burnishing angle being extreme, the Veritas can easily be too aggressive!

JKJ

 

[Paul Vechart]

D-Way tools web site has a good video on sharpening NRS. It explains and shows the honing process too.

 

[John K Jordan]

D-Way tools web site has a good video on sharpening NRS. It explains and shows the honing process too.

He does show proper way to burnish a burr, at about 15 minutes in.

I'm glad he describes and explains the reason for the burnished burr (which he reasonably calls a hook). From the first part of the video I was afraid they were going to discuss only the grinder burr (a far less efficient method of using an NRS, IMO) I also think the the recommened NRS angles are good for some things but not for others. I've made a big variety of NRS configurations and angles and have learned what works best for me for some situations and materials and what works better for others.

I have some of fine the card diamond hones the guy uses and have to say this - even after using them for a long time I found them awkward and more difficult to control than the EZE-Lap "paddle" hones I mentioned.

I haven't had time to watch the rest of the video. Maybe later. It's a slow moving video with the two person format.

(Oh one thing about the EZA-Lap hones - there is some other companies that make similar paddle hones, might be a little cheaper. I bought some of one brand once to evaluate (maybe DMT?). I do not like them. The grit is distributed on what looks like a thin sheet steel surface crimped onto the handle. I think the EZE-Lap is flatter, the substrate thicker, and the grit lasts longer. I haven't used the more recently introduced brands. Try and decide.)

I also have a variety of larger and heavy diamond hones - great for some applications but not for NRS. And if tempted by CBN hones because of the buzzword, don't waste the money. Diamond beats CBN everytime EXCEPT where steels are ground at speed, such as on a bench grinder (where the diamonds will be degraded by the carbon in the steel).

The video link, in case it's hard to find:

View: https://www.youtube.com/watch?v=YsatMuK1Ei8


JKJ

 

[hughie]

This is interesting as I have only one negative rake scraper, what I normally do is lift the handle to offer the scraper at a negative angle especially when the burr has long gone. As all my scrapers are HSS and apart for two [ branded tools ] the rest [ DIY ] fully hardened to the max around 68 Rockwell C. So any burr is only achieved with grinding and really is only suitable for light shear scraping. The HSS scrapers I sharpen at 2 angles 85-90' and 20' they are 3mm thick or 1/8th of an inch.

 

[Bill Alston]

I use a belt grinder to sharpen most of my tools. After sharpening with a 240g belt I then use an 800g belt which leaves a nice polished edge for the hook to be pressed on with the Burnisher. I mainly use standard scrapers though so if there is any sign of a burr after the 800g I remove it with a diamond plate.
These are the belts I use on my Axminster Ultimate Edge. They also fit the Sorby Proedge.

 

[John K Jordan]

As all my scrapers are HSS and apart for two [ branded tools ] the rest [ DIY ] fully hardened to the max around 68 Rockwell C. So any burr is only achieved with grinding and really is only suitable for light shear scraping.

That's interesting. I've never experienced such scrapers. (What type of steel?) It almost seems it might be useful to anneal the end of one a tiny bit to allow burnishing a burr. In my experience a burnished burr lasts a LOT longer than the grinder burr and lightly burnished, can make a smoother surface. But like most everything in woodturning, skills being equal, much depends on what one turns, the wood used, and the methods of work - one size doesn't fit all!

I have a "collection" of commercial conventional scrapers I bought, some large when I didn't know any better (and since gave away), and some I ground from other tools, but almost almost I use regularly I grind from Thompson 10V steel, from his scraper stock, round stock, skews, and even a shallow detail gouge.

JKJ

 

[robo hippy]

Honing, to me means using a diamond stone, generally finer than what you sharpened on. Stropping is another term, and again to me, this is the process of removing the burr. I have a stropping wheel on my Tormek. This is good for removing a small burr, but not the burr from an 80 grit CBN wheel where I have put some pressure on it to raise a bigger burr. So, gentle pressure against the wheel or hone will raise a smaller burr. I do keep several leather strops in my flat work area for bench chisels and plane irons. You can use a piece of plywood or other soft woods like poplar and alder, and use a stropping compound on them. The black stuff at the big box stores is supposed to be about 800 grit. The paste that comes with the Tormek is about 2 to 3000 grit. Generally these are sufficient for most of what we do, but you can go crazy with them. The color of the "polishing compounds" does not relate to the grit. I would think that would be universal, but nope! Most of the time with my NRSs, I don't bother to strop the burr off. I burnish one, using a 1/8 inch carbide rod in a handle. I burnish the grinder burr down and up a couple of times lightly, and most of the time the burr will fall off without needing to be stropped. Some times I just burnish it down first and then back up.

As for the "French curve", to me, I think of the swept back grind gouges, and half of that, so a scraper swept back toward one edge. I have a bunch of different shapes of NRSs, round, square, half round, swept back. long side gentle sweep..... A bunch of them.

robo hippy

 

[John K Jordan]

... Stropping is another term, and again to me, this is the process of removing the burr.

To me, stropping is primarily to polish the cutting edge. I want a "shaving sharp" edge on skews, spindle gouges. The Tormek wheel makes it easy to polish the cutting edges on gouges.

You can use a piece of plywood or other soft woods like poplar and alder, and use a stropping compound on them.

I've experimented and found for me, a piece of MDF with a rough side works well. I resaw a 3/4" piece of MDF into three 1/4" pieces with the bandsaw, rub a stick of one or more of the various stropping/polishing compounds on a sawn side, doesn't seem to matter what kind of compound. Set the thing flat on the workbench, place the bevel flat on the surface, push down with a little extra pressure towards the cutting edge, and pull the skew towards me. You can tell it's removing metal by the blackened marks. A few strokes of this on both sides, and yes, you can shave with it. Works with other tools too but the skew is the easiest.

 

[hughie]

That's interesting. I've never experienced such scrapers. (What type of steel?) It almost seems it might be useful to anneal the end of one a tiny bit to allow burnishing a burr. In my experience a burnished burr lasts a LOT longer than the grinder burr and lightly burnished, can make a smoother surface. But like most everything in woodturning, skills being equal, much depends on what one turns, the wood used, and the methods of work - one size doesn't fit all!

I have a "collection" of commercial conventional scrapers I bought, some large when I didn't know any better (and since gave away), and some I ground from other tools, but almost almost I use regularly I grind from Thompson 10V steel, from his scraper stock, round stock, skews, and even a shallow detail gouge.

JKJ

There are cold saws which have a HSS steel blades 300-400mm dia depending the make and model. The blades are expensive [ down under $150-200 and to sharpen $70-80 AUD ] with a kerf of roughly 2.5-3.0mm that can be re-sharpened. Generally used where very accurate cuts on steel are required. Although the blades can be sharpened many times, when they reach a minimal diameter they cant be used, plus they will break easily if handled roughly. I have collected a number of these old blades and from these I make my scrapers

Best-Quality Cold Saw Blades for Steel Cutting

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sharpedge.com.au

The heat treating of high speed steel is not for novices, see here

1. Preheat: HSS is preheated in multiple stages to minimize thermal shock.
2. Austenitize: HSS is heated to a temperature of 1180–1230°C.
3. Quench: HSS is quenched, generally in air
4. Temper: HSS is tempered in multiple cycles at a temperature of 520–600°C.

The steel in these blades usually is the very best of the HSS. I tend to look for either Dutch or German blades as the steel will hold and edge far better than any others I have come across. No I haven't seen any USA blades where I am, but you probably would want to avoid cheaper brands.

The making of the scrapers is fairly simple, especially if you have a plasma arc. If not the steel can be cut with the 1mmx100mm cut off friction saw ie 4" portable grinder, then ground to the preferred shape. Drilling a hole in the HSS is a bit of a challenge as all conventional methods will fail and the likelihood of splitting is there.

If you have a arc welder, you can up the amps to the highest setting and burn a hole though, this is the simplest method of holding the scraper, you could make a clamping system.

 

[John K Jordan]

The making of the scrapers is fairly simple, especially if you have a plasma arc.

I'm happy with buying and grinding Thompson HSS steel for NRS and have no desire to make my own from scratch. I do have a nice piece of O1 tool steel I intend to cut into Stew-Mac style scrapers of various shapes. Some day...

I do have a good plasma cutter and gas, mig, tig, and stick welders, all handy on the farm. The plasma cutter will cut 1/2" plate clean, 1" sloppy. I REALLY like it when cutting stainless steel. If cutting something thick like a railroad rail I go with the oxy-acetylene - that can be fun. Wear good boots.

Some decades ago we lived near a famous knife maker. He cut knife blades from saw blades he had collected from somewhere and made beautifully handled specialty knives. I have a skinning knife he made. Wonderful blade.

 

[Odie]

I have one of those (haven't used it for years). Good for large conventional scrapers but I can't imagine using one on a negative rake scraper, at least one ground a bit like a skew with small included angle. I think I missed the part about using a Veritas!

John.....just a FYI, the original Veritas burnisher only came with one carbide post. You may have that version. I did, and was able to get the new posts installed on my old Veritas. The new carbide posts are in two different angles, and are taller.

=o=

 

[John K Jordan]

John.....just a FYI, the original Veritas burnisher only came with one carbide post. You may have that version. I did, and was able to get the new posts installed on my old Veritas. The new carbide posts are in two different angles, and are taller.

=o=

Mine has two posts, one tapered. Even with the tapered post, I don't think the angle is useful for NRS, at least for me. But I'm happy with the burnishers I use.

 

[hughie]

I'm happy with buying and grinding Thompson HSS steel for NRS and have no desire to make my own from scratch. I do have a nice piece of O1 tool steel I intend to cut into Stew-Mac style scrapers of various shapes. Some day...

I do have a good plasma cutter and gas, mig, tig, and stick welders, all handy on the farm. The plasma cutter will cut 1/2" plate clean, 1" sloppy. I REALLY like it when cutting stainless steel. If cutting something thick like a railroad rail I go with the oxy-acetylene - that can be fun. Wear good boots.

Some decades ago we lived near a famous knife maker. He cut knife blades from saw blades he had collected from somewhere and made beautifully handled specialty knives. I have a skinning knife he made. Wonderful blade.

Having a plasma arc, the whole process is very simple and well worth the effort

 

[Bill Alston]

When I made my Burnisher there were two Veritas carbide pins offered as spares, 5° and 10°. I bought the 10° version and it works very well on standard scrapers.

 

[John K Jordan]

D-Way sharpening NRS: I haven't had time to watch the rest of the video. Maybe later. It's a slow moving video with the two person format.

OK, I watched the rest of the video. I am somewhat underwhelmed.

JKJ