Thank You Alan!! (Ultimate Scrapers)

[Steve Sawyer]

Thanks and a tip-'o'-the-hat to @AlanCarruth for the scrapers he designed for StewMac. As I've progressed through my current build, this tool has come to almost live in my hand.

It's easy to get some pretty nasty scratches from a rasp in end-grain components like the heel or volute. One of these scrapers makes removing those scratches short work, much easier than trying to sand them out.

They work great on bindings.

As I've started finishing, they are superb for removing runs, sags or drips (I'm brushing Brite Tone). I'm getting about 3 coats on each day, and in the morning, after the most recent coat has had overnight to set up, I'll inspect carefully, and if I find any goofs (like if some finish drips through the tuner holes onto the opposite face, collecting around the rim of the hole), I'll go at the mound with this scraper before I start that day's applications.

Also, I had some spots that needed attention after pore-filling with epoxy. I put one of the pup cavities in the wrong spot, and made a good repair, but had two tiny screw holes where I'd mounted the template. There was also a bit of a low spot next to the repair, and a small shallow divot fell out of the veneer. For each spot, I drop-filled with epoxy, let it cure, then used this scraper to get it almost perfectly flush so that a couple of strokes with sandpaper blended it right in (see below).

I hope Alan gets a nice royalty/licensing fee on these! Highly recommended!

[Alan Carruth]

I know how you feel about that scraper. I learned about the design fro Carleen Hutchins, who got it from Sacconi. It took me a while to get around to making one, and then I wondered why I hadn't done it ten years earlier. All of my students wanted them, and we ended up making them in class. It was a drag. Finally one of the students mentioned that his brother in law had a machine shop, and was looking for a retirement gig, so I offered to help them work up something, and introduced it to the folks at Stew-Mac. I was so happy not to have to make them any more that I didn't ask for any sort of royalty: it wasn't really my 'invention' anyway.

We settled on using D-2 steel for them as a cost cutting measure. The one I have is made of M-2 alloy. It holds an edge about three times as long, but it's more expensive and much harder to heat treat. I'd like to see them come out with a 'delux' version in the better alloy, but I'm not sure they have much of an incentive. Stew-Mac sells a lot of those things, and so does one of the violin suppliers, so their biggest problem is most likely just keeping up. The guys from Stew-Mac smile every time they see me coming, but it's hard to get in touch with my former student....

[Steve Sawyer]

My son is a machinist. I'll have to see if he could make me one out of M-2!!

These are just wonderful!

[Alan Carruth]

The main issue with M-2 is heat treat. The shop cuts them out with a water jet, which should not limit the type of steel used. They then harden them, centerless grind to get the faces smooth and level, and sharpen them. They are left fully hard. A couple of my current students are trying to work up a batch in M-2 now, which should give us a better idea of what a 'delux' version would cost.

[Eric Knapp]

Thanks, Alan, I love mine too. Has anyone tried making one out of O1 steel? That would be much easier to harden and I like O1 tools a lot.

-Eric

[John Clifford]

Is there an effective way to sharpen these without using a bench grinder? I just don't have any room for another power tool. I've tried using a disc sander, and results are OK but not great.

[Alan Carruth]

We tried oil hardening steel of one sort or another; it was pretty similar to the D2. One of the students tried some A10. After hardening it he took it home to remove the scale using his belt sander. He pressed it down on the belt, and barely made a mark on the steel, but he said the belt was like a baby's bottom. After a long session with a diamond stone he got it leveled, and it worked pretty well....

[Gordon Bellerose]

Yes, I have both models, and use them all the time. When I need a scraper, I always go to these first.
Yeah, a sharpening method would be nice to come up with.

[Ian Petersen]

Is there an effective way to sharpen these without using a bench grinder?

An ice skate sharpener works quite well - like this: https://www.skatemate.se/en/

Ian

[Alan Carruth]

"Yeah, a sharpening method would be nice to come up with."

I assume you've seen the video, using a bench grinder? Failing that a skate sharpener would probably be the best way.

[Chuck Morrison]

After reading this thread I bought a skate sharpener and a few cheap sharpening stones. The sharpener (with 2 grit sizes) and the round stones have the same diameter, about 1/2" and the right size for the scraper. Although it took a while to get the original deep scratches out of the hollow edge, this seems to do the trick and leaves a nice surface. I look forward to using this scraper a lot more now. Many Thanks !

scraper

[Barry Daniels]

Chuck, I am not sure that that will work. The small radius will create too sharp of an angle on the cutting edges which might ruin the scraping action. I sharpen my scrapers on an 8" diameter wheel which keeps the cutting edges very near 90 degrees, which is optimal.

[Alan Carruth]

There's no reason why the skate sharpeners can't work, but the edges may not hold up as long. I usually touch them up at least once after the initial edge is lost. Lap the face as per usual, then stand the scraper up on it's edge on a fine diamond stone and hone small flats on either edge. This helps keep the edge straight, and gives a fine burr that's well backed up for final cuts.

[Carl Dickinson]

I've used a 3" grinder to do this. It worked ok for me. StewMac has one, kinda pricey, but I used the $38 one from HF https://www.harborfreight.com/bench-gri ... 43533.html.

[Chuck Morrison]

Thanks for the tip Alan,

Oddly enough it didn't take long at all to get the original sharpening gouges out with the skate sharpener and it went right to the edges quickly, so It doesn't seem that far off of the original curve in spite of the small diameter. Maybe some slop in my technique is a better explanation. I like the idea of ending with a diamond stone as you describe. That should take care of any issues from too small an edge and make a smoother cut as well.