First time using card scrapper - lower my expectations or...

[Mishkin Derakhshan]

Just got a Bahco card scrapper. Sharpened it per Mike Popovich youtube video.

I polished the faces with my 1000 and 8000 stone.
Then used 300, 1000, and 8000 stones to square off and polish the edges.
Then I drew out the steel (4 or 5 light passes per side).
Then I drew the hook. I tried two or three light passes and and as many as 10 much harder passes on another edge. Didn't seem to make a big difference.

I could barely feel a burr. Much less than what I'm used to when sharpening a chisel or plane iron. Is this correct?

When I went to scrape, I did get shavings. well, dusty shavings (see picture).

BUT, I'm a little disappointed with the surface finish. I was expecting a 320+ grit sand paper, glossy smooth finish given how much everyone talks up scrappers. Don't get me wrong, i managed to get rid of the tearout I was getting with my plane, but I still feel like I need to sand before I apply finish. Is this the expected result, or do I just suck?

thanks379449

[Patrick Chase]

The shavings are within reason for a card scraper with a small burr, so let's focus on the surface finish.

What is specifically wrong with the finish? Are you seeing striations, fuzz, or something altogether different?

If you're seeing striations, what happens when you lightly run your fingernail along the length of your scraper's burr? Does it "catch"?

Without knowing how much of a wire edge you draw when grinding your description of your burr doesn't tell me much. What are you using to burnish and how much pressure are you applying? One oft-cited description is "enough to spread butter", and I think that's about right.

[Pete Taran]

In my opinion, two things are at issue. One, spending that much time on edge prep with three different waterstones is a waste of time. I rarely stone at all, and when I do I use an old black Arkansas stone. The stoning lasts about 45 seconds.

The likely culprit is the application of the burr. You really need to apply some pressure as after all, you are rolling hardened steel. You need to burnish the face of the scraper and then roll the edge. To burnish the face, clamp the card to the edge of your bench so it is even with the edge. Then take your rod and with just a few degrees of angle really bear down hard as you move back and forth along the edge. This is part of the reason why it's a waste of time to overstone your scraper. The slickness of your burnishing rod, well, burnishes the edge and removes the scratches from filing (assuming you use a mill smooth file).

When that is done, clamp your card in a vise (saw vise works great) and prepare to roll the edge, I like about 15 degrees, You can use a little bit of oil if you like to help in this step, but I rarely do. Using the same burnishing rod, again, press hard while holding it at about 15 degrees and draw it across the edge. You obviously want to roll the burr toward the burnished face. Check for the burr with your fingernail. If you can catch it in the burr, you are good to go. If not, or it's not enough, give it another swipe and repeat until it is to your liking.

Here is another pro tip that most won't tell you. After your scraper stops cutting, just roll the burr back as before by burnishing the face. Then reroll the burr. You can easily do this twice, sometimes three times before you have to draw file again. Also, you can put a burr on both sides of the same edge. It works great and cuts down on filing and burnishing. When I was making IT saws, I relied a lot on scrapers and had two burrs on each long edge. When they were all dull, I moved to another scraper and when they were all dull, I spent 30 minutes rehabbing the edges.

Like anything, practice makes perfect, but worry less about stoning and more about getting the feel for the pressure required to burnish the face and roll a burr. I know you can do it.

PS. I just read Patrick's description of pressure as akin to the amount required to spread butter. In my experience, it's more like the amount of pressure to push a plane through wood. Any amount of pressure will work, it just depends on how many passes you need. The harder you press, the more steel you move. Unless you really enjoy fiddling with burnishing rods, more is more in this case.

[Bob Glenn]

You may presenting the scraper at an angle that is too aggressive, IE. : leaning it too far forward as you push it across the wood. To get a really clean cut with a freshly sharpened scraper, I hold the scraper perpendicular to wood then angle it forward just enough so it begins to cut. Leaning it too far forward usually results in a rougher cut and dulls the scraper sooner. Don't give up. A little experimentation is in order. Good luck.

[Robert Engel]

Mishkin,

I think you've got the basics down very well. Keep at it. Remember the smaller the hook, the better the shaving and the longer it lasts.

You will get a duller surface compared to a plane. A scraper can produce a finished surface, but on a large area I always follow up with sandpaper.

"Scraper" is actually a misnomer because the hook is cutting the fibers of the wood. When you are actually "scraping" you get dust.

Drawing out the metal before turning the hook is a critical step.

One thing I think people often do (at least I did) when first learning this is too much pressure with the burnisher. It takes surprisingly little pressure to make it work.
What William Ng's video.

[glenn bradley]

One thing I think people often do (at least I did) when first learning this is too much pressure with the burnisher. It takes surprisingly little pressure to make it work.
What William Ng's video.

The degree one spends on an edge tool vary widely. Using turners as an example; there are turners that polish their skews and there is the camp that go directly from the bench grinder to the work. I 'mill file' my scraper edges using a guide to help me stay square. This is just a block of milled wood with a groove cut in it to hold the file. I then stone at 600 and 1200 on diamond plates since they happen to be my preferred sharpening medium for this task.

Like you I pull the edges but, only use a swipe or two. I do not soak my scraper in oil as William Ng does but, rather I add a drop of light machine oil to my finger tip and brush it along the burnisher. Adding the hook is where a lot of people go wrong IMHO. One or two swipes is ll it takes; overworking this step fouls your edge.

Once you get comfortable sharpening your card scraper you can get creative. I have one very yard scraper that I pull about a 5 degree hook on one edge and a greater increment angle on each of the remaining sides. The greatest angles are on the short edges as I use these for aggressive scraping of trouble spots. You don't have to mark the edges the difference in intensity is easily felt with your finger.

[John C Cox]

I clamp a fine cut file in a vise and give the scraper a couple passes across it... Off to the races. When it slows down - I give it a couple more passes and back to work.

If I am feeling particularly froggy - I will turn the burr with a screwdriver. They do cut better this way....

[Patrick Chase]

Mishkin,
"Scraper" is actually a misnomer because the hook is cutting the fibers of the wood. When you are actually "scraping" you get dust.

This is exactly right. A properly formed burr cuts the wood at a plane-like angle, and then immediately "breaks the chip" on the vertical face of the scraper.

I realize self-referencing is poor etiquette, but see the pretty picture here: https://sawmillcreek.org/showthread.php?261460-Image-of-scraper-burr&p=2768244#post2768244

[Andrew Seemann]

Hi,

For a first attempt, I think the shavings look great. For sharpening I don't bother with stones either, I just clamp the scraper in the shoulder vise about an inch up and hit the sides with a fairly fine file and then do the top with the file until I have the edges square and sharp. If I need a finer edge I might hit it with a diamond credit card, but I don't in normal usage. Then I use the back of a carving gouge to turn the burr. I just push it across each edge once around 15 degrees or so, using my pinky knuckle on the bench top as a guide. I usually do all the sides at once (because I tend to use all sides until they are dull). For whatever reason, for me the burr isn't damaged in the wood vise jaws.

I'd say just use the scraper more often to get used to it, try different angles, burnishers, files, etc. Also try different techniques, including ways that people say are wrong, like pushing towards your body, pushing away from your body, curving it, not curving it, using different grips, using it one handed, etc. I find that pretty much every way of using a scraper is considered wrong by someone. I've actually gotten pretty good at using the scraper one handed, which I think is considered wrong by everyone, but it works for me and sometimes is easier on the arthritis.

One thing I learned is that the burr needs sharpening more often that I was lead to believe, and less than 5 minutes an edge is not unrealistic depending on the wood. That is part of the reason I don't take a lot of care in sharpening the scraper, the edge dulls pretty quick no matter what you do, so there isn't much incentive to do more than what is minimally necessary. I usually go over the scraped surface with at least a light sanding to smooth everything up and even up stain/sealer absorbsion.

The scraper is definitely a tool worth learning; it is one of my favorites and I am not shy about using power sanders.

[John C Cox]

This is the closest video I could find to what I was taught...


http://www.youtube.com/watch?v=2Qze5C6BxWA

[Patrick Chase]

This is the closest video I could find to what I was taught... (Ron Hock video snipped)


I'd never seen his video before, but I think its a good minimalist approach. A few observations:

His overview of how scrapers work at the beginning, and particularly the comparison/analogy to a plane with a close-set cap iron is dead on.
He does pretty minimal stoning, basically just enough to get rid of whatever burr the file left.
He doesn't bother "drawing" the flat face before turning the hook. I've gone both ways on that, and to be honest I don't see much of a difference.'
His description of the amount of force required strikes me as reasonable (even though he argues against the "butter spreading standard" that I mentioned above :-)

[Derek Cohen]

I do two things differently, and these do make a difference.

Firstly, the steel is drawn out (note that the burnisher is pushed at a skew) ...

http://www.inthewoodshop.com/WoodworkTechniques/FoolproofSharpeningOfCard(Cabinet)Scraper_html_701 b7dc5.jpg (http://i13.photobucket.com/albums/a262/Derek50/Scraping/8a_zpsglunosp4.jpg)

Secondly, the hook is turned to a max of 10 degrees, and this is done in two stages, first at 5, and then at 10. This will create a stronger hook as it is less susceptive to fracture ...

http://www.inthewoodshop.com/WoodworkTechniques/FoolproofSharpeningOfCard(Cabinet)Scraper_html_40a 8c05e.jpg (http://i13.photobucket.com/albums/a262/Derek50/Scraping/10a_zpsb4m0gixk.jpg)

Here is the scraper turning shavings. Notice the angle of the scraper here ...

http://www.inthewoodshop.com/WoodworkTechniques/FoolproofSharpeningOfCard(Cabinet)Scraper_html_13b 1f000.jpg (http://i13.photobucket.com/albums/a262/Derek50/Scraping/11a_zpspyeoqxi7.jpg)

Because he turns a higher angle (15 degrees), Ron is forced to tilt his scraper over further ...

https://s19.postimg.org/64qtbdks3/Screen_Shot_2018-02-21_at_6.04.38_pm.png

You can say whether our shavings are similar or not, and if not, in what way they are different.

Regards from Perth

Derek

[steven c newman]

Each response seems to be a bit different...makes it even more confusing to the OP.

Too many versions to just flip a coin, and try one over the other.....about normal for sharpening threads around here...

[Pete Taran]

Seems like the common themes are:

A mill file is your friend
Ditch the hours of honing
Turn a burr using something hard and using moderate pressure
Adjust the burr angle to suit the work you are trying to accomplish

Those seem to be the common themes. If you watch Ron Hock's video, you will notice he spends no time at all doing that, which is exactly how I do it.

[Jebediah Eckert]

Mishkin, I had (have) the same issues with surface quality. I tried asking the same question and got similar results. A ton of good suggestions on methods, pressures,angles etc etc. They were all great and I read and tried most of them. Some very useful tips that made sharpening easier with better results.


But, The question still lingers.......



No matter how you prepare and use your scraper is surface left behind finish ready?

(Robert’s answer to the question is what I end up doing. After my use they don’t leave a glass smooth surface like a handplane, but I don’t know if that’s normal or not)



Using your preferred method can you use your card scraper to touch up some light tearout and go right to finish?

[John C Cox]

Each response seems to be a bit different...makes it even more confusing to the OP.

Too many versions to just flip a coin, and try one over the other.....about normal for sharpening threads around here...

Steven,

Here's what it boils down to in my experience......

If you need a scraper to deal with nasty grain and clean up the surface between Planing and sanding - get out the fine cut file and screwdriver. That's what you need. This makes a fairly large burr that cuts aggressively. Every time it gets dull - give is a quick couple passes on the file and off you go. It will leave fine tracks and slight lines... It's not really good as a final finish for show faces....

If you want to scrape instead of sand as a final finish.... Get out the stones and hone the scraper to form a very fine burr. Use a proper smooth burnisher to form and polish the burr. These do not cut aggressively - but they leave a buttery smooth finish that glistens...

Hope this helps.

[Patrick Chase]

But, The question still lingers.......

No matter how you prepare and use your scraper is surface left behind finish ready?

Yes, but only with a perfectly prepared scraper, and not for very long. If the burr is uniform and well-shaped, and if I can lightly run my fingernail down its tip/edge without any catching then it will take a clean shaving without tracking. I can still get a higher-sheen surface from my planes, though.

+1 to Derek's comments about angle. I would add that a lot depends on how large of a burr you're trying to create, and whether you "draw" the scraper's surface with flat strokes before turning the burr. If like Hock you just turn the Burr from a square corner then you have to use a relatively high angle as he did to get a reasonably-sized burr. If you "draw" the surface first then that gives you some extra material to work with at the very tip, which allows you to turn a smaller angle and still have a decently sized burr.

My own philosophy these days is to minimize how much I "touch" the scraper's edge, because IMO every manipulation is just another chance to mess it up and leave tracks on my work. I therefore *don't* draw the burr, and I turn at a higher angle (10-15 deg).

The smoothness of the burnisher is also an oft-neglected variable. My own Crown burnisher was too soft and got nicked up, and those nicks left defects in the burr leading to tracks. I have a steel Pfeil burnisher that seems quite hard and works well, and I also have a piece of solid 1/4" Tungsten Carbide rod (from McMaster Carr) that works well. Some people swear by the Arno Carbide scrapers as well.

[Jebediah Eckert]

Thanks Patrick!

[Steve Hubbard]

+1 on Glenn's advice to add a liitle oil, or WD-40, to the burnisher. That made a big difference for me.

[Derek Cohen]

If you use polished carbide, then lubrication appears unnecessary. The polished carbide "floats" smoothly over the carbon steel.

Regards from Perth

Derek

[Patrick Chase]

If you use polished carbide, then lubrication appears unnecessary. The polished carbide "floats" smoothly over the carbon steel.


Carbide burnishers are more or less immune to galling.

I still lubricate very lightly, mostly out of habit, but I don't think I really need to with the WC bar that I now use for most burnishing.

[Philipp Jaindl]

Sharpening a scraper so far has been more of a gamble then anything else for me, sometimes i get fantastic results others not so much. I never thought about lubricating the burnisher i'm gonna give that a try, also Hocks Video does help, seems like i tilted over the burnisher a bit too far and used too much force sometimes.

One question i do have is once it gets dull(er) are you going straight back to filing or can you "re-burnish", for lack of a better term, an existing hook?

[Derek Cohen]

Philipp, I joint the edge of the plate after a 3-4 "sharpenings" (what does one call the process of turning a hook?). It becomes evident how many times you can do so since the steel will stop scraping. The hook becomes progressively weaker and cannot be turned back. Then it is time to joint the edge flat and square, draw out the steel once again, and turn another hook.

Regards from Perth

Derek

[Patrick Chase]

Philipp, I joint the edge of the plate after a 3-4 "sharpenings" (what does one call the process of turning a hook?). It becomes evident how many times you can do so since the steel will stop scraping. The hook becomes progressively weaker and cannot be turned back. Then it is time to joint the edge flat and square, draw out the steel once again, and turn another hook.

Every time you manipulate the edge you create fractures that can expand into chips or other discontinuities. For me the limiter to re-burnishing is when the tip of the hook is no longer a perfectly continuous and uniform edge, such that I feel variations in "drag" when I draw my fingernail down its length. When that happens it's time to joint the edge and start over.

I seldom get more than 2 burr-turnings between jointings. By that point I can almost always still create a reasonable-looking burr, but it doesn't pass the uniformity test and will leave tracks on the work.

[steven c newman]

All too complicated for me......I just cut a new edge on a piece of glass and go back to work....maybe a bit of kerosene on the glass cutter...

Cut but cut to the profile of any molding. Edge gets dull? cut a new edge. Price? Go to about any Glass place and ask for their scrap barrel..Or, IF the neighborhood brat breaks another window...save the pieces.

Sometimes known as "Glass-papering" Have used this for quite a few decades. It also works to shape a hammer's handle, for a better fit..BTDT.

[Patrick Chase]

Sharpening a scraper so far has been more of a gamble then anything else for me, sometimes i get fantastic results others not so much. I never thought about lubricating the burnisher i'm gonna give that a try, also Hocks Video does help, seems like i tilted over the burnisher a bit too far and used too much force sometimes.

What are you using for a burnisher?

If it's made of steel and on the soft side (like my old unlamented Crown) and if you haven't been lubricating then it's likely that the burnisher itself has been damaged due to galling. If so then you'll want to get a new one, because it won't draw a clean burr even with lubrication.

Burnishers don't have to be expensive. My current burnisher of choice is a 1/4" polished Tungsten Carbide rod bought at an industrial supply house (McMaster-Carr here in the US). I think I paid $20.

[John C Cox]

Sharpening a scraper so far has been more of a gamble then anything else for me, sometimes i get fantastic results others not so much. I never thought about lubricating the burnisher i'm gonna give that a try, also Hocks Video does help, seems like i tilted over the burnisher a bit too far and used too much force sometimes.

One question i do have is once it gets dull(er) are you going straight back to filing or can you "re-burnish", for lack of a better term, an existing hook?

Philipp,

The easiest and fastest thing to do is to clamp your fine file in a vise and give the scraper 2 passes on each side... Back on the wood without even burnishing. As soon as it dulls - flip it to another edge. Once all 4 edges are dull - back to the file which is still clamped in your vise.. You will be back on the wood in 60 seconds... It's not a final finish sort of operation - but you will get the hang of it quick. And once you get the hang of it - you can fool with burnishers, hook angles and all that... But it's not necessary..

[Derek Cohen]

Building on John's comment about draw filing an edge, one of my favourite scrapers is simply prepared with a bench grinder wheel.

I made the following out of the end of a 3/16" thick O1 plane blade. It must be flat (as above).


Take it to the grinder (mine uses a 180 grit CBN wheel) and create a hollow around the edge.


http://www.inthewoodshop.com/WoodworkTechniques/FoolproofSharpeningOfCard(Cabinet)Scraper_html_m7d be30df.jpg (http://i13.photobucket.com/albums/a262/Derek50/Scraping/Sharpening-blade-scrapera_zpslgrvfjha.jpg)
http://www.inthewoodshop.com/WoodworkTechniques/FoolproofSharpeningOfCard(Cabinet)Scraper_html_740 a8fcc.jpg

It is almost effortless ...
https://s19.postimg.org/ll31hkdr7/1_zpspr2v0uh1.jpg
Regards from Perth

Derek

[Patrick Chase]

The easiest and fastest thing to do is to clamp your fine file in a vise and give the scraper 2 passes on each side... Back on the wood without even burnishing. As soon as it dulls - flip it to another edge. Once all 4 edges are dull - back to the file which is still clamped in your vise.. You will be back on the wood in 60 seconds... It's not a final finish sort of operation - but you will get the hang of it quick. And once you get the hang of it - you can fool with burnishers, hook angles and all that... But it's not necessary..

This is probably a good point to note that scrapers have a multitude of applications within woodworking, with different demands in terms of preparation etc.

Most of what I've said in previous posts in this thread assumed that you're doing final smoothing and trying for a finish-ready surface. If you're not then you can be a lot less OCD about it than I've implied, turn the burr more times from a single jointing, etc.