Sharpening Round and Straight scrapers.

[John Frigillana]

:rolleyes: Any suggestions to sharpening scrapers straight and round. Mine are just starting to just burnish the surface. That's how long I have ignored the fact.
Any input and jigs that would help?:confused:

[Jeff Nicol]

Keoni, Just set your tool rest on the grinder at the angle of the scraper and swing it around until it is sharp. That is all I do and it is fast and works fine. If you want you can hone them and raise a bur with burnisher made of carbide to get the best burr, but that is up to you. I change the angle once in a while to see what works better but as long as there is a bevel away from the edge it should cut. The secret to all of this is to try what works for you there are so many answers to these type of questions and some work for one person but not another. Test the waters and then jump right in, for experience is the best teacher.

Jeff

[Bruce Shiverdecker]

To the best of my knowledge there are two schools of thought. In both cases, you need to take a magic marker and color the bevel. during setup you will be able to see when you get it right.

1. Set the table on your grinder in an upward angle that matches the bevel. Place the tool topside up. You'll know your setups right when you get a mark of equal width nose to heal on the bevel. Keep the table about 1/4" from the wheel. When you are done, get your burnishing rod, that you use for cabinet scrapers, and bring up a burr on the top edge.

2. This is a little more tricky, but it saves time and work. No having to bring up a burr. It's already there. Set the table at a DOWNWARD angle NO MORE than 1/4" from the wheel. (Don't want the tool to get caught and smack you in the jaw!) Place the tool on the plate upside down. Just as before, make slight adjustments till your mark is even tip to heel. Slide the bevel across the wheel and you're done. The burr is there.

The reason the second works is that the wheel is running off the tool instead of into it, thereby forming the bead. The first way would remove any burr that was there, making you make a new one.

Just my thoughts on the matter. Not necessarily right or wrong. You might want to test it yourself.

Bruce

[John Frigillana]

:confused:What about the Sorby Teardrop scraper? That doesn't have a bevel to it ,just straight. Do you just grind that the same way also?:rolleyes:

[Reed Gray]

I have one of the Veritas adjustable tool rests/table, and it stays at one angle, about 75 degrees or so, but I never measured. All of my scrapers are sharpened on it, including tear drop, coring, and hollowing tools. Lay them as flat as possible, and swing through the round arc, or sweep across for the square. I never turn them upside down. I don't burnish a burr, as I prefer the burr I get from my grinder wheel which is an 80 grit wheel, that is rather fine for an 80 grit. I use my scrapers a lot, especially on bowls, probably more than gouges.
robo hippy

[John Frigillana]

:rolleyes:It that the Veritas Scraper Burnisher that sells for around $40 that can be bolted down or used in a vise?:confused:

[Greg Haugen]

I use three scrapers in my box turning. Two round nose scrapers and one modified square scraper. I was taught how to use scrapers by Alan Lacer (his article in the AAW a couple issues back is excellent on scraper sharpness). I sharpen the scraper on my wolverine platform, right side up-I've never sharpened it upside down. The only time I've heard of this being done is a friend of mine sharpens her small tip for the Sorby Multi Tip upside down since the underside is "rounded". After I've "dressed" (when sometimes the word "grind" or "ground" are used it doesn't convey the "light touch" that sharpening requires) the bevel of the scraper, I hone the top of it with a "Fine" diamond hone to remove the grinder burr. The grinder burr is only as "keen" as the grit of the wheel on grinder. For some applications, like bowls, this may be preferred, similar to a bread knife's cutting bread. For boxes and end grain work I like the keenest edge I can get. The removal the bulk of the waste of a box I'll use the scraper now. Freshly ground, no burr-honed off. The scraper will be "less" aggressive/grabby but I can actually engage more of the edge hence removing more wood. For the finishing cuts, I'll raise a burr with a burnishing rod and apply a "shearing" angle to the scraper. The diamond honed flat, burnisher raised burr acts as a microscopic hook tool and creates the finest, smoothest surface.

Scrapers aggressiveness can easily be decreased or increased by using a diamond hone and a handheld burnisher. These tools are incredibly flexible and versatile.


Just my two cents....

[Ron McKinley]

We had Don Derry last Sunday for a demo and during the break he demonstrated his burnisher. First, he sharpened a scraper on the grinder, passed it around for us to feel. Then he honed off the burr and ran it through his burnisher. The burnished edge burr was much smoother and lasted much longer than the ground one. The burnished edge is less aggressive and gives a smoother cut. I tried it at the demo and liked it so much I bought one.

Haven't had the chance to try it in my shop yet but will later today. The key is to run the scraper through the burnisher at an angle and not flat on the plate. You want to get the burr "off the edge" a bit instead of directly on top of the edge of the tool.

You can take a look here: http://www.derrytools.com/burnisher.html

I use scrapers on bowls to remove the ridges left by the gouge and on some woods I only use scrapers for most of the work. Like most of us I have trouble with tear-out of the end grain and I'm hoping this scraper will help.......Ron

[Kyle Iwamoto]

And I was thinking I was the only one who burnishes a scraper..... Is this Derry burnisher clamped in a vise? Seems like a good tool, although I already paid some serious bux for a Crown rod burnisher. It's kind of a pain in the you know what to hold the scraper and the burnisher AND try to maintain a consistent angle. This seems to be a good idea. 35 bucks is less than I paid for the rod burnisher. BTW, I bought it for a card scraper, but it was hard to get a good edge. So I got the Veritas burnisher for my card scrapers. So, I guess the lesson learned here is don't buy the rod burnisher, get the card burnisher and this Derry tool......
Thanks for the info.

[Greg Haugen]

Wow! That's steep. I have a burnisher that I bought from Alan Lacer for $19/handled and it's made by Hamlet Tools. I like the hand held style since it's more universal and I can easily change the burr's size and angle.

[Kyle Iwamoto]

I paid more....:mad:
There was a small one, and a BIG one. So I figured bigger MUST be better... Well, not. The small one would probably be better, since the bigger rod has more area. The small rod would have more pressure on the scraper. The card burnisher has like a 1/8" rod.
I couldn't get the edge consistent along the cards with the hand held..... Even in the vise. It may also be that I burnised too hard and/or too many times. I read later, that you actually can over burnish, and make the hook like a mushroom, and that works, well, like a mushroom.....

[Wally Dickerman]

I set my Oneway tool rest at 60 degrees and sharpen all scrapers at that angle. That includes the small teardrop scraper used on my Stewart hollowing tool. I use the 60 grit wheel for a good burr. A couple of quick passes of the tool and a fresh burr is raised. No need for a burnishing tool, which can put a too agressive burr on the tool. Tools last a long time when the grind is the same every time, requiring only a touch up for sharpening.

When sharpening a negative rake scraper I use my 1 inch x 42 sander with a 60 grit zircon belt. Gets a more aggressive burr. When using the NR scraper on very hard woods, sometime it works best with no burr.

For the occasional reshaping of a tool, I find that the belt sander does a much faster job that the grinding wheel and with less heat.

Don't quench high speed steel in water when hot. Makes the edge fragile with hairline cracks.

Wally

[Reed Gray]

Raising a burr with a hand held burnisher is difficult. With a round rod almost impossible, but doable with a triangle burnisher.
robo hippy

[Ron McKinley]

And I was thinking I was the only one who burnishes a scraper..... Is this Derry burnisher clamped in a vise? Seems like a good tool, although I already paid some serious bux for a Crown rod burnisher. It's kind of a pain in the you know what to hold the scraper and the burnisher AND try to maintain a consistent angle. This seems to be a good idea. 35 bucks is less than I paid for the rod burnisher. BTW, I bought it for a card scraper, but it was hard to get a good edge. So I got the Veritas burnisher for my card scrapers. So, I guess the lesson learned here is don't buy the rod burnisher, get the card burnisher and this Derry tool......
Thanks for the info.

This burnisher screws into a tool post and clamps into the banjo. Very stable......Ron

[Michael Mills]

In the Sorby video's they show using a diamond file on the top of the cutter, not the edge. On mine, I remove the cutter and a few strokes (12?) on a diamond plate and it is ready to go again. I have never honed or ground the edge.
Mike

[terry richards]

Use whatever works best for you. I do not burnish - straight from the grinder to the wood.

I grind my scrapers right side up at 50 - 55 degrees top plate angle, which works better for me than the more square edge. I do use scrapers in various angles, shearing at 45 deg. or so about as often as I truly scrape, riding the bevel whenever the cutter is above the tool rest.

For the purists in the audience, I refer to the tool when shearing as a "flat topped gouge."

Set the tool rest no more than 1/8 from the wheel. Light passes are all that is required, as long as you are not re-shaping the tool. Once it is set, I do not move it, sharpening all my scrapers at the same angle. I hone at the lathe between grindings with an India stone.