best type of file to sharpen card scrapers

[Mike Leung]

I did a search but couldn't find an answer. There are so many kinds of files. What is the best type to joint card scrapers? Thanks

[Fitzhugh Freeman]

Mill file, single cut, bastard or second cut (single cut means it has one set of teeth as opposed to double cut, while second cut is the fineness of the file: smooth, second cut, bastard, course - confusing choice of terms).

I have a bastard file that I use for it, not sure if it is better to use second cut, but google "draw filing" if you're not familiar with the technique. Not sure, but I believe with draw filing the difference between bastard and second cut is minimized.

A few things I've figured out by doing them wrong before paying attention to what I read, any or all of which you may already know, or may be wrong:

-Use file ONLY on short edges, not flat sides. Some websites suggest you should file off the old turned edge as part of sharpening. I used to do this but it left the sides of the edge full of scratches. It might have been from poor filing technique but it had the same result as having scratches all down the back of your plane or chisel blade. Edges didn't last at all. It took forever to hone them out.

-Use a light touch when turning the edge. "use only as much pressure as you'd use when buttering bread" I read that in some article somewhere and it made a BIG difference.

-Make sure the flat sides are honed, not just the edges.

-Make sure the edges are truly flat, not at all rounded. This makes sure the sharp corners (running out of terms, normally I'd call them edges, but I'm calling the small flat sides edges) are sharp. Might not be exactly 90 degrees if you use the "ruler trick" but close enough.

-Use little pressure on files, let them do the work, not the pressure you put on them.

-Joint the edge by draw filing - hold file perpendicular to edge and pull across in smooth motion. Then hone the resulting wire edge off with fine stone or paper, then turn edge.

-Sharpness is not about the angle of the point as much as the radius. A super small radius on a 90 degree edge can be SHARP, while a 10 degree knife blade can be dull but look sharp. There are times I just joint the edge and use the card without turning and edge. I lay the card nearly flat on the surface and push the card across the surface. I find I can sometimes get surfaces true more easily this way when they are small or can't be reached by a plane (I don't have a chisel plane or bull nose plane).

Card scrapers are one of the most useful tools I own but I'm still not great at getting consistent results.

[Gary Hodgin]

I use a 10" smooth cut mill file.

http://www.lie-nielsen.com/catalog.php?grp=1358

[Jessica Pierce-LaRose]

. . .
-Sharpness is not about the angle of the point as much as the radius. A super small radius on a 90 degree edge can be SHARP, while a 10 degree knife blade can be dull but look sharp. . . .

Anyone who's held a Narex mortise chisel by the edges of the blade while chopping can attest to this . . .

[David Keller NC]

I did a search but couldn't find an answer. There are so many kinds of files. What is the best type to joint card scrapers? Thanks

"Best" is a relative term. I can (and have) effectively straightened and squared the edges on a cardscraper by draw-filing with an ordinary $3 BORG bastard file. But, the edges needed quite a bit of subsequent work on my sharpening stones, and I really don't like doing that because of the potential for grooving/gouging the stones.

I bout one of the Glen-Drake Toolworks scraper file-burnishers a while back and now dress my many card scrapers exclusively with it. While a pricier option than a BORG smooth-cut or mill bastard file, I figure the Glenn Drake tool will last my lifetime because I only use it on card scrapers. The file is fine enough that I don't bother with stoning the edges of a card scraper after using it; I just turn the burr.

Here's the Glenn-Drake tool:

http://play-glen-drake.com/v-web/ecommerce/os/catalog/product_info.php?cPath=31&products_id=66&osCsid=9b703d91f8e1e3332e5cbe50f4b338db

[jason thigpen]

Anyone who's held a Narex mortise chisel by the edges of the blade while chopping can attest to this . . .

Glad I'm not the only one who's experienced this!

[Mike Leung]

Thanks for the tips guys. I'll look for a single cut smooth file.

[phil harold]

100 grit 4" wheel
grind 5 degrees from square

jimmy d'aquisto taught me this

[Paul Saffold]

+ 3 or whatever with the Narex.