Thread: Sharpen Card Scraper

Same problem here. I’ve tried the Veritas and Woodsmith and no joy, just dust.

I think it is just a matter of getting the knack. I had a lot of problems at first, until I saw a tip on a blog somewhere. It linked to a video and the point was ‘don’t overdo the pressure on the burnisher’.

Get your edge juice and square, refine it on a stone. I then hold the scraper on end in one hand and burnish the edge with the other hand. I suspect that you can overdo it and the hook can roll right over.
Bruce


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Originally Posted by bruceward51

I think it is just a matter of getting the knack. I had a lot of problems at first, until I saw a tip on a blog somewhere. It linked to a video and the point was ‘don’t overdo the pressure on the burnisher’.

I think the problem is any D head with Hobby Time on a bench can make a movie on how to do things, get it wrong and make a fool of themselves at the same time .
In amongst all that are plenty of gems of info, but there is a lot of annoying rubbish with guys who love the sound of their own voice.
And you guys are watching it .

Your trying to push saw plate steel sideways off a square edge so you need pressure not limp light passes.

Originally Posted by bruceward51

Get your edge juice and square, refine it on a stone. I then hold the scraper on end in one hand and burnish the edge with the other hand. I suspect that you can overdo it and the hook can roll right over.
Bruce

If such a thing could happen then the angles your using would have to be pretty out of whack.


Rob

I wonder how much user technique becomes a factor after the scraper is sharpened?

Due to not being in the shop for a year or so I haven't used my card scraper in a while.

As simply as possible, to sharpen a scraper you remove the burr and then put the burr back on.

Put the card scraper in a woodworking vise with about 2.5 to 3 CM proud. Use a mill file to straighten the edge of the scraper. You should remove any remains of the burr.

With a three sided burring tool held at an angle 15° or 20° from horizontal rub the edge of the card scraper. Usually three passes are enough. Use some 3 in 1 oil (Sewing machine or Gun oil are substitutes) to reduce the friction during the rub. Hold the burring tool the opposite way also from the horizontal and rub the edge of the scraper. Clean the oil off the card scraper and it is ready for use.

To use the card scraper it is best to push away from you. When holding the scraper put a slight bend so that the scraper is convex away from you. The burr is what really removes and smooths the work.

I have found that I can re-burr the scraper a couple of times before having to take the file to it.

With a three sided burring tool you can easily put a large, medium and small burr on the scraper all with the same relative pressure. Just use the smallest, medium and large edges, respectively. It is also possible to put different burrs on the same edge of the card scraper. Typically I'll put a large and a small on one edge with two medium on the other edge. You can feel the differences between the burrs.

There is one thing that I forgot. When using the scraper it is easier to work away from you. Hold the scraper at about 15° to 30° off of vertical when you scrape.

Actually it's worse than that, you forgot that you remembered.

"To use the card scraper it is best to push away from you"

I'd be confused if I could remember what I was trying to understand...

I have believed for some time that old age is cunningly designed to soften us up for the end. When the time comes rather than being afraid I'll be welcoming that sucker with open arms...

Hello sussertown, The latest edition of fine woodworking has an article on sharpening card scrapers. volvo

I use pieces of glass as a scraper when they loose the edge,into the bin.
Local glaziers have heaps of pieces to give away.
With a glass cutter I sometimes cut a profile to match what I am finishing.
Haven't used a metal scraper for 40 years.
Cheers
John T

Originally Posted by rjtwin501

I use pieces of glass as a scraper when they loose the edge,into the bin.
Local glaziers have heaps of pieces to give away.
With a glass cutter I sometimes cut a profile to match what I am finishing.
Haven't used a metal scraper for 40 years.
Cheers
John T

OMG! Interesting! My 6,7,8 year shop teacher would have us scrape the work benches the last week before summer vacation. He would give us pieces of about 5-6MM glass to do the scraping. During the summer he would come in and varnish all the benches.

Of course that wouldn't happen today. "What, children scraping with shards of glass? Where are the lawyers when you really need them?"

I am the lazy one. I file the edge for a few seconds to get it straight and square. I repeat the process as often as I want to.

When I first started trying to use a scraper, I found I was over-burnishing the edge. I use a file to get the edge square, and a stanley screwdriver to burnish it. When I first tried, I used to run a few times over with the burnisher, but found it's much better to do a single pass, with the scraper in one hand, and the screwdriver in the other hand, and as much pressure as I can in this setup. If you have the scraper in a vice, and use two hands on the burnisher, I reckon you could over-burnish it in one pass. I do the angle by eye, but I guess it's 5 to 10 degrees.

Redoing the edge, I will flatten the hook with the scraper flat on the edge of the bench, using the screwdriver on the flat, and redo the hook as above. Probably every 5th resharpen, I'll put the card in the vice and re-file the edge, and sometimes I'll use some 400 grit paper to get a really nice edge, but I often don't bother.

But, the main thing is to be able to do a quick sharpen with very little setup. I don't want to spend 15 minutes or more sharpening the scraper only to get 10 minutes scraping out of it, and I don't want to have to pull out stones, paper, file, burnish, and pull my project out of the vice every time I resharpen. I have the screwdriver ready beside me, and a flatten+re-hook of the edges will take me a minute or two. Not every edge is good every time, but the scraper has 8 edges. If one of them is no good, I just move on and work with the others. The quick turnaround is also great because you get quick feedback on what sharpening methods work.

Anyway, the trick for me was the one-handed, single pass burnishing.

What I think nobody has mentioned is that when you roll the edge you must keep the pressure right to the end so the burnisher drops off and hits the bench with a thud.

It’s called “ticketing” because (as poms as old as me will remember well), the machines that bus conductors used to use to punch the holes in tickets made a similar clack-clack sound.

I found this method in a magazine somewhere and it worked well:

Make a hardwood block, maybe 150 x 100 x 50

Get a new file which you’ll dedicate to this

Make a slot about a third up the long side of the block so the edge of the file is a snug fit

Put the block in the vice with the file in the slot and resting on the jaw

File the scraper edge, keeping the side of the scraper against the block so it’s at right angles to the file (you’re moving the scraper not the file)

Sharpen on the stones, using the same wooden block to keep the scraper perpendicular, this time scraper and block move together and move over the stones so you don’t wear a groove. I used a diamond plate and then water stones.

Put the scraper in the vice and roll the edge.