Tuning Card Scrapers

[Bob Smalser]

In previous articles, I described rehabbing older Bailey-pattern planes acquired from Ebay to replace all the family’s ancient wood planes…the ones I’m getting tired of inlaying mouths in every decade or so as they wear. I’ll rehab these oldies one more time and pass them on to my oldest boy who’s interested in luthier work…he’ll be the 5th generation of craftsman for some of these. I’ll describe resoling these woodies in another article, but as my card scrapers are essential tools for this work and mine all need a tune-up, I’ll walk you through that process today.



I pull the mahogany filing block out of the bin…any hardwood block the length of the file with a dead square rabbet to serve as a shelf for the file will do… and while holding the chalked file in place with my left hand I run the scraper down the teeth until I’ve filed away all the old wire edge and have a nice fresh, square surface to turn a new edge from. The chalk aids in preventing the single-cut mill file from clogging and I’m careful to not slide the scraper backwards against the file’s teeth….a practice that dulls files exactly twice as fast as necessary.



A nice, fresh, dead-square edge.



Then moving both block and scraper to the Arkansas stones, I hone the edge dead smooth on coarse and fine stones. The smoother and squarer the edge, the better and more durable the eventual cutting edge.



Then I clamp the scraper to a hard, flat surface and use a burnisher to turn a wire edge inwards on both edges as shown in the sketch. The burnisher? The one I’m using is a luthier design by Timberline Tools of Mendanales, New Mexico, but any hardened and smooth steel will do….like the back of the old Buck Brothers gouge shown or a valve stem or pushrod from your local junkyard. The burnisher should be oiled for best results.



Then I simply affix the scraper on edge and turn those wire edges outward to make two hook edges as shown in the second sketch. The purpose-built burnisher does that automatically and rapidly….when using the gouge, I use two hands and rub the edge on a diagonal with the burnisher beginning horizontally and pushing the gouge twenty or so degrees downward during each stroke.



The result? The scraper, held in both hands and sprung a bit toward the body as it is pulled toward you, cuts this hard maple sole like a plane….only with more control and precision. Learn to use scrapers, and you’ll cut your abrasive paper outlays to a pittance and even that varnish finish coat that egg-shelled on you won’t be a burden. That’s right…properly tuned they can cleanly remove as little as one layer of varnish.



I’m not into unnecessary tools, but this luthier’s burnisher halves the time and effort of tuning the scrapers. You can either buy or make one. How do you harden the 5/16ths drill rod? After it’s cut to length and the edges eased, simply grab it with soft-jawed pliers, heat it to cherry red with a propane or MAPP torch, and toss it in a pint can of linseed or motor oil….too little oil and it’ll catch fire….and do it outdoors, OK?





“When we build, let us think that we build forever. Let it not be for present delight nor for present use alone. Let it be such work as our descendants will thank us for; and let us think...that a time is to come when those (heirlooms) will be held sacred because our hands have touched them, and that men will say, as they look upon the labor and wrought substance of them, ‘See! This our father did for us.’ “ --John Ruskin.

[mrohde]

That's one I've been looking for. I've got a question, though.

When doing the first step with the burnisher - where you go from a square edge to a concave edge - how exactly do you do that? Are you removing material from the center of the edge and leaving only the sides somehow? Or, are you somehow pushing the sides of the scraper up past the edge?

Thanks,

Matt

[WoodMangler]

Hi Matt

I believe this is what Bob is referring to with that step...

... at least this is what I do before I roll the edge over to make the actual hook... Coulda showed ya the other night! ;)

The burnisher is run along the edge rolling the steel over sorta kinda like shown (sorry, lousy drawing) which gived the concave edge effect....

http://a6.cpimg.com/image/40/44/3169...-02000154-.jpg

[RustyBrooks]

Bob, great explanation as always, much appreciated.

I've been wondering what could be used as a burnisher. They sell them, of course, for $20 or so, but that seems like an odd thing to buy if all you need is something hard and round.

People have recommended using a drill bit that was never chucked. I guess to guaruntee a smooth surface? Would you recommend that with your tempered section of rod there? I had some old drill bits that I could sacrifice.

How is the rod secured in the wooden holder? Or is it?

That's definitely something I'd have to give a try.

And for the record, I'd love to see a lesson on how to make the wooden body of a scraper plane.

[mattf53]

Thank you for two vewry informative articles. I build Muzzle loaders and use scrapers to shape them and finish tem. This will help me a lot

[Bob Smalser]

Any hard, smooth piece of steel or ceramic can burnish...like the gouge in the article. Auto engine valve stems and pushrods chucked into a handle are popular.

That pin in the purpose-built burnisher is a tight press fit...but it could also easily be epoxied in.

[mrohde]

The drawing is perfect. It conveyed the meaning and I understand.

Thanks to both of you for the help. I have to go to Woodcraft, now.

[Cody Colston]

Why don't you put all of this stuff on a web site or in a book?

It would be convenient to have it all in one place for reference instead of scattered throughout a bunch of woodworking forums.

Just a thought.

Cody

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The expert at anything was once a beginner...

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