cabinet scraper sharpening wisdom sought

[Scott Winners]

Egad, a blatant sharpening thread.

I have been down in the cabinet scraper rabbit hole for about a week. I think I have learned some things, I am much better at sharpening them now for sure.

I am going to share what I think I have learned, I have some observations, and then hopefully I can pick up some other finer points from all y'all fine folks.

I am leaning mostly on Leonard Lee's "Complete Guide to Sharpening," Tauton Press, c 1995, herein after "LL."

And secondly Brian Boggs' Bench channel on youtube, hereinafter "BB" specifically this one:

Is this the one? > https://www.youtube.com/watch?v=Uf0UEVPSJUI

jtk

Yes, that is exactly the one Jim. I have seen a couple dozen other youtubes and not wasting our time with them.

It seems to me the first step is to flatten all the faces so the ready to sharpen scraper has 90 degree edges in all the places. LL published photos of stoning his scrapers on the sides of his water stones to save wear and tear on the top surface.

I did notice BB used the same poplar guide block on two different grits of diamond stone, and I think he is exacting enough to notice if he was polluting his fine stone with loose diamond brought over from his coarse stone. I am going to remake my honing guide for card scrapers out of poplar later tonight. I am going to use a little bit of shim material so I can actually slip a card down in the slot without having to spread open the ends.

The biggest magnifier I have is 4x, with the head band and the flip up visor feature and I am really glad I dug it out. While I am learning to see, some magnification is a wonderful thing.

So with the blank fully prepped and stoned, the next step, I think, is just enough burnisher strokes in the usual directions to get a burr large enough to catch a fingernail, but small enough to be hard to see.

This is the first of my assumptions I question. When working with bare unfinished wood, can anyone come up with a compelling reason to make a larger burr, perhaps just big enough to see with the light at any angle? It just seems wasteful to me. A burr is very fragile, making bigger burrs seems like (to me) just wearing out the card scraper faster.

How many burnisher strokes to take is all over the map. LL mentions card scrapers used to be more or less 38-41 Rockwellc, the new stuff is Rc48-52; so I thought the folks needing lots of strokes maybe had the new harder stuff, but BB comes along and refers to his scraper as "Fairly soft, around Rc55."

I decided at my place to just go through the process repeatedly to find out. I don't know how hard anyone else is pushing down on their burnisher. I started with 2 draw strokes on each corner, then two strokes flattening the cat's ears, then 2 strokes on each corner rolling the burr, then 4 of each, finally getting somewhere at 8 of each, and now happy at 10 burnisher strokes for each step, 5 down that way and 5 more back up this way. This technique works for me on both my L-N and my 2 cherries card scrapers. I have no idea how many burnisher strokes you need at your place on your tools. But I know how you can find out.

The second assumption I am questioning is dealing with more and more difficult woods. I think what I see is the smoothness of the burr is more important than having the burr at any particular angle -> given my goal is the smoothest possible surface on bare unfinished wood.

One of the pics below is marginal Ash whispies on the top edge of my planing stop, but the same scraper (without resharpening) is going gang busters on the pictured hickory. My hope is my upcoming poplar guide can support the entire length of burr rolling, because as pictured the top left corner of my scraper is going to flex as the burnisher passes over.


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[Lee Schierer]

I struggled with sharpening my scrapers until I watched this video from Fine Woodworking.

[Derek Cohen]

It was not long ago that I posted this ...

https://www.inthewoodshop.com/ToolRe...Burnisher.html

1. Stone edge

2. Draw out steel

3. Use this burnisher.

Done.

Drawing out steel ...



Burnishing the hook (one hand used to hold the camera – but this process is as easily done with one hand as two) ..





This is a nice tool. Not essential, but it provides a consistent hook.





Regards from Perth
Derek

[Edward Weber]

One thing I didn't see mentioned is the thickness of your scraper.
The sharpening process will be the same but often thinner cards get bent more than thick ones during cutting. This, along with the cutting angle, can effect how well it shaves the wood in a certain circumstance.

[Jimmy Harris]

To me, card scrapers are one of those things you can't really learn from a book or video. I mean, you can learn the steps, but you won't really learn how to do those steps until you've sat down and run a bunch of experiments on your own. Luckily, it doesn't take long to put a burr on a card scraper, or to remove one and start over. So I say just spend an afternoon playing around with one and figure it out on your own. You'll know when you get it right because you'll get shavings instead of dust. And then you'll learn how hard to push down and at what angle and how many times to swipe, etc. It's only complicated until you figure it out.

[Rob Luter]

I struggled with turning a hook for years. The Boggs video is a great teaching tool. I was always being too aggressive. Start with a clean and straight edge. Gently turn a hook. Easy peasey.

[Mel Fulks]

Don’t see much about the burnishers any more. The agate ones are the best.

[Rob Luter]

Don’t see much about the burnishers any more. The agate ones are the best.

I have a collection of them. Three from Buck Brothers shown below. The pointed ends are handy for shaped scrapers and beading cutters. I also have a pretty one from LN.

[John Kananis]

Imho, folks overcomplicate sharpening these things. Make it quick and easy as you'll have to draw out a burr far more often than sharpening a plane blade. Don't use guide blocks (waste of time, just bend the scraper when you run it across the stone and it'll stay completely perpendicular to the stone. You can use just about anything as a burnisher that's somewhat hard (even a screwdriver). So, remove the edge, hone and burnish. Also, don't draw the hook all the way to the side (a lot of times these things are sharp but can't cut because the burr is too far "in"). Small angle, better cut.

[Tom M King]

For years the best burnisher I had was a Crown awl. I've tried a number of different types of tungsten rods, including some that were polished to start with. This particular one off ebay is as good as any and better than most, and the cheapest I've found. I'm not sure how it will show up in this link, but mine is a 4mm x 100mm. It even sharpens scissors easier and faster than other methods. I think it must have the perfect surface texture.

https://www.ebay.com/itm/183909476311?var=691602772408

[Scott Winners]

I did make a new guide block out of poplar, and am using the "rule of 60" as explicated by LL above to turn a burr around 5 degrees. I will see about using fewer strokes for the burr curling step in the future.

I got out my best edge and a bunch of scrap species today. I am talking about difficult to scrape, not hardness. If I accidently say 'hard' in the following, I am not talking about Janka #, I meant to say difficult to sharpen for.

With my best edge this morning, I can smooth ribbon grain Sapele, but I get dust. The other two in my shop that are particularly difficult are QSWO and American Beech.

Flat sawn White Oak, Teak, figured cherry, straight grain cherry, walnut, hickory, flat sawn red oak, ash, straight grained hard maple, all in my new easy group.

I have searched on 'abrasive wood' a few different ways, but get a lot of hits for sandpapers on sale now. I did read somewhere that American Beech is an 'abrasive wood,' but i don't have a reference and don't have a list of the others.

I don't have any tropical hardwoods other than Teak and Sapele. If someone sends me some Jarrah and asks me to make something with it I will start with some smoked potato slices in the BBQ pit 'cause that stuff is intimidating.

The list above is pretty much everything I have in the shop for hardwood. I have a little tiny bit of fiddleback walnut and a little tiny bit of quilted maple; but those are small enough quantities I am not willing to experiment with them. I don't have any figured maple.

If you are getting nice curly shavings on quartersawn white oak, Sapele or American Beech your card scraper is 'sharper' than mine is today.

I still think the crux here is uniformity of the curled burr and that is where my ongoing effort is going. I did find a 5x magnifier (at Kroger of all places) today, but am very likely to find a 10x something online in the very near future since I can't find 10x local. Both team orange and team blue list 10x product under $20 on their websites, but neither will deliver that product to Alaska.

[Rob Luter]

Well it’s been a couple three weeks. Did you crack the code yet? I was scraping a project tonight and as I was refreshing the burr I thought about this thread.

[Scott Winners]

Did you crack the code yet?

I still think uniformity of burr trumps all. Yesterday was the first time I had 30 minutes in the shop since I clocked in at my real job at zero dark on New Year's Eve morning.

All the changes I have adopted that have improved the surface of my workpiece have to do with making the burr more uniform. Other than doing it "just like Brian Boggs (qv)," I did build a second poplar guide, again with two pieces s4s, a shim and a couple screws. The wet one on my diamond stones seems to soak up soapy water pretty quick, the wood swells, it gets tricky to get the next scraper in the gap. So I made another to keep dry for the burnishing portion.

I also got out my router plane. I have a maple block I have been using for the drawing out step. I cut and inked a line 3/4 inch back from 2 faces so I can get a consistent angle on the burnisher for the drawing out steps. Eventually the corner of the maple block will wear and I will get a do-over, but for now that step is uniform and consistent from end to end on each edge - and for successive sharpening events.

I did also draw out, exaggerated, what happens if the edge of the scraper is not perpendicular to the grinding stone. One side will already be "drawn out" a little bit, so the two burrs will be different. I don't like it.

I am going to order a 10x loupe tonight before I post anymore here. I do have a 5x lighted magnifier that shows me a lot I couldn't see otherwise, but ever once in a while I will be flattening out the cat's ears with my burnisher and see an imperfection I hadn't noticed before when that edge was on the stones.

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I could be wrong. I live at the NW corner of the paved roads in North America. There is no furniture tradition here. There is, that I know of, no one in town I can entice to my shop with ribeye and beer to help me with my hand tool challenges. The good news is I sometimes try some things that aren't supposed to work because I don't know any better.

In the moment, my hypothesis remains that uniformity of burr trumps all else when trying to smooth a flat surface with a straight edged card scraper.

NB: I am now very well connected to BB's idea to have a metric butt ton of similar scrapers and sharpen them all at once when they get dull, rather than take one scraper round and round the shop through all the steps.

[Derek Cohen]

Scott, if you wish to create a uniform burr, it is important to have enough steel to do so. This translates to first "drawing out" the steel ...



You want to pull the steel outwards with the burnisher. You will not create a proper hook without doing so. About 5 strokes from the left and 5 from the right.


The burr/hook should be done in two parts to avoid fracturing the steel ...

Turn the hook at about 5 degrees. Do the 5 and 5 again ...



Then do it again but at closer to 10 degrees.

The burnisher here is a thin length of polished carbide rod given to me about 15 years ago. It is fantastic - polished carbide does not need any lubrication. Others steels will gall the steel plate.

The one-size-does-it-all burnisher ... that is turns a hook at the perfect angle, and on both sides of the steel ... is the Accu-Burr, which I referred to in my earlier post.

Regards from Perth

Derek

[Scott Winners]

I have a bunch of tabs open looking at 10x magnifiers on that web site named after a large river just now. Having seen some magnified views on that otherwise nameless website I pulled out my COED. I happen to own a (nominal) 10x magnifier that was made before all the optical glass on planet earth became MiC. (c) on the new edition COED is 1991, mine is 1995-ish.

Next question is do I want wood shop oils and sawdust on the magnifier for my personal COED. She is otherwise a beauty... this is the only book I own with a separate user's guide.