"Ultimate" scrapers

[Bernie Daniel]

I wonder how many are using these Stew-Mac "ultimate" scrapers (http://www.stewmac.com/Luthier_Tools/Types_of_Tools/Scrapers/StewMac_Ultimate_Scraper.html)?

They are much thicker than typical cabinet (or card scraper) and they are made from D2 tool steel which is much harder material also. In fact they are essentially a hard as a burnisher so to sharpen them you have to cut a hollow grind on the working edge using grinding wheel with a fine stone.

Here is a video on them. I bought a set and I was really amazed at how well they work. I wonder if I will ever use my card scarpers again. (And I just learned how to sharpen a cabinet scarper too! :crying: )

They cut cleanly for long time too. I have used one of them to carve the re-curve on a maple mandolin back plate and I well over half done with it and the scraper has shown no sign to dulling -- I am still getting nice clean shavings.


https://www.youtube.com/watch?v=a7XRbfbpXiE

[Dale Ludewig]

Thanks Bernie. I've been interested in these things for awhile. I've wondered if the edge would hold up longer than on a regular scraper. I often go from the grinding wheel to work even with a regular card scraper, even more so with one of the French curve variety.

[fscotte]

Why would the burred edge last any longer than any other edge? I don't see it.

[Bernie Daniel]

Why would the burred edge last any longer than any other edge? I don't see it.

My guess would be first, because it is much harder metal and second because it is not a burred edge or a least not a drawn and burnished burr -- it is a hollow ground edge. Did you watch the video? It definitely does last a lot longer in my experience using them so far.

BTW International violins is selling them too and on discount until January 4th I think.

[oldwave maker]

My recycled handsaw blade scrapers have been gathering dust since acquiring the large and medium from International last year. Been retouching edges with the flat 2x6 diamond plate as in the vid. Best I've used for recurve refining and scraping celluloid binding.

[Jim Hilburn]

Now that's what I call a recommendation.

[billhay4]

I like mine, too.
Bill

[Michael Lewis]

I have one of the early ones from Al Carruth, and I like it but it does not replace all my other scrapers. One thing is it doesn't flex, so you can't make it fit a particular contour, you get the curves it has and that is it.

There is no burr edge on these scrapers, just a sharp edge barely more acute than square. It DOES hold an edge.

[Bernie Daniel]

I have one of the early ones from Al Carruth, and I like it but it does not replace all my other scrapers. One thing is it doesn't flex, so you can't make it fit a particular contour, you get the curves it has and that is it.

There is no burr edge on these scrapers, just a sharp edge barely more acute than square. It DOES hold an edge.

Thanks for the clarification on the scraper edge!

I did not think it could be called a "burr" either but Al Carruth, the guy in the video, does use the word burr in his presentation. That part kind of confuses the issue a bit since in my book this is a classic hollow grind edge.

How do you sharpen your heavy scrapers?

If you use a grinding wheel what diameter is the stone? I am wondering if a smaller diameter wheel, which would give a steeper (deeper?) concave edge -- might be better for maintaining a longer use life between sharpening?

Asking because I am about to buy a grinding wheel! :)

[j. condino]

If you've got a grinding wheel, you can make a drawer full of your own scrapers for 50 cents worth of scrap metal from any junkyard in the country.

j.
www.condino.com

[fscotte]

Seems you'd have to be very careful to make sure the edge is flat. Too much pressure on the wheel in one place or not enough in another would really screw up that straight edge.