Polishing Stones

[Israel]

There is a nice video on YouTube of William Ng teaching his method of sharpening a card scraper. He starts by using "polishing stones" to flatten the side and edge of the scraper, and emphasizes that these are very different than "sharpening" stones. Could someone explain the difference, and also tell me where to get a true "polishing stone" as the words "sharpening" and "polishing" seem to be used interchangeably in the descriptions one reads about such stones…
Thanks!

[djwong]

I think William Ng is saying to use a fine enough stone that does not leave visible scratches. All sharpening stones will abrade steel and leave scratches, depending on the type of abrasive and grit size. Generally speaking, from 4000# and higher, the scratches are fine enough to polish metal.

[Wilbur Pan]

^This.

By polishing stone, William Ng is referring to high grit waterstones, anywhere from 4000 grit on up. I’ve seen other card scraper sharpening demonstrations where an 8000 grit waterstone is used for that step of the process, so it’s not just something that William Ng does.

[Derek Cohen]

Israel said:

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There is a nice video on YouTube of William Ng teaching his method of sharpening a card scraper. He starts by using "polishing stones" to flatten the side and edge of the scraper, and emphasizes that these are very different than "sharpening" stones. Could someone explain the difference, and also tell me where to get a true "polishing stone" as the words "sharpening" and "polishing" seem to be used interchangeably in the descriptions one reads about such stones…
Thanks!

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I have just posted a "Foolproof" tutorial here: http://www.woodcentral.com/woodworking/f...abinet-scraper/

I only use one stone for all my scraper sharpening: a well worn 600 Eze-lap, which is now about the equivalent of a 3000 stone. The advantage of a stone like this is that it does not groove. If you do not have similar, try a newish 1200 grit.

Regards from Perth

Derek

[Anji12305]

I use a similar method devised by Brian Boggs of North Carolina.

A 4S wooden block is made with a central "slot" just wide enough
to admit the scraper lengthwise. This makes holding the scraper easier and provides a reference to keep "on the square".

It is important to note that you MUST keep the burr properly turned for a scraper to function. When it stops cutting, you'll know.

http://www.finewoodworking.com/how-to/vi...raper.aspx

FYI - I use a cheapo two sided Diamond plate to prep card scrapers.

[Derek Cohen]

No jigs needed. A wooden guide for the card is similar to a honing guide for a plane blade. Learn to do it freehand. If you can saw on the vertical, then you can hold a card on a stone at the vertical.

In any event, the "secret" to preparing a card is not how square the edge is. It is how you draw the metal at the sides, and then how you turn the hook.

Regards from Perth

Derek