More 112 woes

[James Taglienti]

So I read the article in PWW about burinishing a scraper. The part about honing the 45* grind like you would a plane or chisel was new to me, so i tried it. The card cuts beautifully for about 5 strokes and then the edge fragments and becomes rough. I can't feel it too much on the board but I'm certain the cut quality is pretty poor after this...
I am scraping some wild-grained white oak. The card is a Garlick or whatever, the saw makers. It seems like the card is chipping at grain reversals. I can't plane this stuff, it's so hairy.
Please don't tell me the 45* bevel is just for well behaved woods. I really like how it cuts for the first 30 seconds, and well behaved woods get planed anyway.

[Mike Siemsen]

James, If you were reading the article by David Charlesworth about setting up a cabinet scraper and ground a card scraper like that it is no wonder you are having trouble. The 45 degree grind is for cabinet scrapers and 112s and such not for card scrapers. If you are using it in your 112 then I am not sure why you are having trouble. I use my #80 set up as he suggests and it worked fine in hard curly maple. Maybe try rolling a smaller burr.
Mike

[James Taglienti]

I don't know wither... do you know of a decent replacement cutter for the 112? I'm not trying to spend $50 but i think i need something a bit thicker than a standard card

[Tom Henderson2]

I don't know wither... do you know of a decent replacement cutter for the 112? I'm not trying to spend $50 but i think i need something a bit thicker than a standard card

Hi James-

I think part of the confusion is terminology.

The 112 is a small scraper plane, and uses a thickish blade, like a plane blade. So the blade is essentially rigid. Preparing the blade as DC describes should give good results. Double check that you have the blade oriented properly.

Card scrapers, OTOH, are just thin steel stock and usually pretty flexible; they are used "freehand" without a supporting structure. By applying pressure in the proper locations, the flexibility of the card can be put to your advantage. Prepare these cards by squaring the edge, then polishing and rolling a burr.

So your discussion of using a "card" in a "112" is confusing some of us....

-TH

[george wilson]

We had some Garlick saws in Williamsburg before I became toolmaker,and remedied the situation. Those saws were the softest saws I have ever seen,and very roughly ground on the surface of their blades. I suggest you get an OLD Disston saw and make your scrapers from it.

The Garlicks are not going to be hard enough to hold a decent edge while scraping butter.

[Rob Fisher]

I don't know wither... do you know of a decent replacement cutter for the 112? I'm not trying to spend $50 but i think i need something a bit thicker than a standard card

Check out the Hock blades for 112. I think craftsmanstudio.com has them for like $26.50.

Rob

[James Taglienti]

Clarification- I am using a Stanley #112 scraper plane. Tom- is thare a larger scraper plane available than the 112? In it I have placed a standard card scraper that just happened to be the proper width. I know how to prepare a scraper card for use. Perhaps it is too thin. Perhaps the steel is not good, or at least not good enough for use in a scraper plane.

That's it... the card has got to be bad, or too thin. The card that came with the plane was a saw cutoff, a bit thicker, but it seems worse than the Garlick one.

I thought that any piece of steel used for scraping was called a card. IE the 112, 80, 212, etc, all take a "Card" not a "cutter." When does a card become a cutter? when it's mounted in a plane? Is a cutter thicker?

I will have to check the thickness of the Hock and try to cut my own from a hand saw. I've got about 5 dozen handsaws laying around. If the handsaw part doesn't work, I'll buy a hock. If that doesnt work, I'll give the 112 to my wife to use as a sad iron.

How long should a decently prepared cutter last in a 112?

[Jeff Burks]

The cutter that came with the #112 was around 70 thousandths thick if I recall correctly. The Lie-Nielsen #112 (http://www.lie-nielsen.com/catalog.php?sku=112) cutter is 125 thousandths (1/8") thick and performs much better. The Ron Hock #112 cutter is ~94 thousandths (3/32"). Most card scrapers and hand saws are in the 18-35 thousandths range with some exception. A really stiff miter box saw may be 40-50 thousandths.

A card scraper is way too thin to be used in a large scraper plane due to the amount of force, friction and heat generated by the tool in use. Chatter during the cut will have a negative impact on the life of the burr, and I would imagine the primary purpose of the thicker cutter in the larger planes is to reduce chatter. I make hand scrapers all the time out of hand saws but don't think those are even thick enough to be used in a large scraper plane, especially when you put a 45° bevel on the edge prior to turning the burr. Though I suspect the real problem here was the piece of steel you were using. If the same scraper performs poorly when used by hand then it is probably to blame. I have also seen people use poor quality burnishers (not hard or polished enough) or poor technique (too much force) create burrs that broke down quickly in use. The burr will also break down early if you fail to polish the edge of the cutter or card.

"When does a card become a cutter?"

Probably when you sharpen the end like a plane blade. Also when you can no longer flex the piece easily in your bare hand.

Should also point out that the burr on a scraper is about 1/2 Thousandth of an inch projection. If the metal is soft, or the burr is ragged, it will not hold up under any conditions. A ragged burr is usually formed by a burnisher with light rust or imperfect smoothness. The quality of the burnisher is very important if you want to get a continuous burr. The continuous burr is much more durable than a lot of short burrs with little notches and scratches dividing them. Even the most microscopic crust or pit in the chosen burnisher will damage the tiny burr as you form it. And a small amount of oil really helps preserve an intact edge when drawing and turning the burr.

The other cause of a ragged burr is a scraper with unpolished faces and edges. I know this guy who uses his card scrapers to scrape wet glue squeeze out. There is so much light rust and glue deposits on his scrapers that he can never turn a proper burr on them. He is too lazy to polish all the edges, and the faces where they intersect the cutting edges.

The scraper burr ignores grain direction because of the short distance from the burr edge to the flat body of the card, which acts as a chip breaker. The 1/2 thou burr never gives the fibers a chance to tear before they are folded back and snapped. The burr is required when you intend to go straight to finish from the final scraping. The burr is a cutter that will shear the fibers cleanly, leaving a high quality surface.

Btw - There is also a nice method of sharpening card scrapers with a file and no burr which is quite acceptable for certain types of work (where the scraper is not the final tool). It is well explained and demonstrated in these videos 1 (http://www.youtube.com/watch?v=d3sqDWFAA0s) 2 (http://www.youtube.com/watch?v=s2mO_ItlBXw&feature=related). This type of edge leaves a much rougher surface than a burr, but excels at rapid stock removal in a controlled manner.

Also, most of the information presented in the PWW article is also available in video format on David Charlesworth (http://www.davidcharlesworth.co.uk/)'s DVD - Furniture Making Techniques: Five Topics

One of the topics covered is "Dealing with Difficult Grain":
Modifying Effective Pitch with a Back Bevel
Re-Sharpening a Back Bevel
Modifying Effective Pitch on Block Planes
Scraper Planes: Another Approach

[James Taglienti]

Thank you!

[bridger berdel]

When does a card become a cutter?


when it becomes sharp enough to cut.

[jerry nazard]

Jeff Burks: that was a great post. Thank you!

-Jerry