Card Scrapers......how to "freshen up" the hook during use?

[George Farra]

Hi Everyone,

I finally figured out how to sharpen a card scraper. I'm working with figured cherry and its been great to eliminate tool marks and mild tear out. I've noticed that the cutting edge doesn't last very long and I quickly go from making shavings to saw dust in a matter of 15-20 strokes. I also noticed the scraper itself get hot in my hands.....so I'm guessing I'm using it wrong.

I let up on the downward pressure and that kept the tool cooler, but still got warm. I still only get about 20 strokes and then I need to resharpen. Like a plane iron...is there any way to "hone" the edge to keep the tool working longer, or do I need to go through the entire sharpening process over again.


My sharpening process:

- Via the Veritas Jig, I file the edge clean
- Via 600 and 1000 grit paper I polish the sides and the edge
- Burnish the side to draw out my bur
- Burnish the edge straight across to spread the bur out
- Burnish the edge at 5-10 degrees to turn the hook

Any help on my sharpening technique or how I am using the tool is greatly appreciated. I hold the tool at approx. 45 degree angle and apply pressure with my thumbs to bend the tool slightly towards the work.

Thank you,

George

[Jim Koepke]

Hi George,

We may be in the same boat. My card scrapers are nice to use but they tend to have a delicate edge that doesn't last.

It seems they may be only useful for small area touch ups and not in the board feet per hour arena.

Hopefully someone will come along and let us in on how to change that.

jtk

[Terry Beadle]

I found the trick to keeping an edge on a scraper is to not use a lot of pressure to create it in the first place.
I learned this technique while watching Mr. Ng's video on card scrapers. He makes a burr that is smaller and that
allows him to reshape or refresh it in just seconds.

Here's the url : https://www.youtube.com/watch?v=Nz6EpQu2HRo

It's introduced by the wood whisperer but goes right to Mr. Ng's school studio.

Enjoy!

[john zulu]

I use Mr Ng. method for sharpening. 20 strokes? It is either too much pressure or the steel is crappy. I have the LV set. It works well enough.

[Jessica Pierce-LaRose]

Hot is normal - I usually use a holder, or wear gloves- a fridge magnet on the back also helps keep the heat from burning your thumbs.

Like Terry says, a hook that goes away too fast is one you made with too much pressure for that scraper. You end up with a giant, fragile hook that doesn't last. You'll be surprised at how little pressure it requires to get a good hook.

[lowell holmes]

You can touch up the hook by laying the scraper flat on a flat surface (saw table) and take the hook out by a stroke with your burnisher.
You then burnish a new hook by running the burnisher down the edge, the same that you did when you burnished the new hook.

The scraper does get hot when you are scraping. It sounds to me like your doing a good job.

[George Farra]

Thanks everyone!! Much appreciated, george

[David Weaver]

Cherry is variable, and if you're scraping curly cherry, you're going to have some low density areas. I'd make sure you're taking advantage of the whole scraper and roll a burr on several edges.

I've had some dense cherry that rolls nice shavings off of a card scraper, and others that roll sickly shavings. If it's the wood, and you're otherwise fine, you can take a test piece of hard maple and scrape it. Maple, beech, etc, stuff of that hardness scrapes beautifully. If you get great scraping off of maple and the cherry yields dust of half dust, then it's partly the wood to blame.

The higher the polish on your scraper, the better chance you have of rolling a sharp burr that will work on marginal wood. Even at that, something like a medium stone should be fine, make sure when you're testing out new methods that you've gotten a fresh edge.

Functionally, rolling the burr should be a few strokes to draw it out and then a few to roll it. Light pressure (as everyone said above) on rolling the first burr to preserve your ability to roll a good many more before having to restone or file.

Heat is good. Well, it doesn't always feel good, the scraper heats fast when it's working well.

[Darrell LaRue]

Scrapers, gotta love them.

I built a sleighbed for my son a few years back. Holy cow, that was way back in 2001, time flies! The panels are coopered from strips of beech, and then scraped smooth. Scraped and scraped and scraped. Madness? Nope, it worked great. Much of the smoothing of the inside curves was accomplished with a curved scraper. I got to know and love my scrapers on this project.

Yes, they get hot, and yes they dull fairly fast on hard woods. But they sharpen easily, that's why they dull so fast. And don't worry too much about dust versus shavings. In fact you really only want shavings during the 'rough' scraping phase. Once you get near your finished surface, you want a very light cutting action, and dust is fine. If you burn your fingers just slap a fridge magnet on it and keep going. It'll insulate you from the heat a bit. And when your thumbs get tired, shift your grip. Pull the scraper instead of pushing. Use fingers instead of thumbs. I wish I could show you, it only takes a few seconds, but its really hard to describe.

I have a couple of rough scrapers that just get draw filed and then go to work. For shaping they are great. Need a new edge, run the file over it once and you're back in business. For smoothing and final finish, I have scrapers that are polished and burnished. A couple of swipes flat on the bench to kill the hook, then a couple of swipes (one for each side) along the edge to re-turn the hook and you get back to work. You can keep doing this dozens of times before you have to file and polish a new edge. You just have to have a very polished burnisher, and the edge of the scraper must be lubricated. If everything is smooth and polished and lubed, the hook will come right back with a couple of passes of the burnisher.


296430

Darrell
who ignores common wisdom, like "you can't scrape softwoods" and just uses the tools and gets good results, so there.

[Adam Cruea]

As was said, scrapers do get toasty. My thin one ends up almost burning my thumbs.

And Mr. Weaver is correct. . .Maple scrapes beautifully. At least soft maple scrapes very beautifully.