Official Luthiers Forum!

My wonderful wife bought me some stuff from Stew-Mac. One of the items was the Carruth Scraper. Been wanting one for some time. I honestly do not know how you could appreciate this tool unless you have used card scrapers and sand paper on guitar projects. This thing is pure genius! Not to mention almost zero finger strain. The way the corners are designed are perfect for leveling purfling without squeezing or thinning the binding.

Mr Carruth, thank you!

Mike

I couldn't agree more!! If she didn't get you the set you'll be wanting the mini one too.

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Steve Smith
"Music is what feelings sound like"

Where do you find the mini useful?

I dread the moment I have to sharpen it. I will be buying a new stone for the grinder. But I worry about the radius. The current edge looks like it was done on a small diameter wheel.

Mike

But yes. It is an amazing little tool. I will probably buy more just because.

That was the mini I was using on the bindings. Sharpening is not that hard. I have one of those low speed grinders from Woodcraft with the white wheels and it works fine. I just flattened the sides on a diamond stone and then gently ground the edge on the fine wheel. I set up the guide to be at right angles to the wheel. Easier than I expected.

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Steve Smith
"Music is what feelings sound like"

Why do you flatten the sides? I know little to nothing about sharpening these. And I won't attempt till I know everything

The little note that comes with the scrapers tells you how to sharpen them. There's also instructions on StewMac's website. It's just lapping the sides to get rid of any burrs that may be there before you grind the edge. I ground the edge very gently, just enough to see that I had made new marks on it all the way across.

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Steve Smith
"Music is what feelings sound like"

...it seems like unless you were able to move the arced edge at an exact consistent speed/force against the wheel, you would get a scalloping effect, on the curved scraper edge. unfortunately i have the tormek, but no Carruth scraper... but knowing tormek, they probably have a jig for those too

those crazy swedes... on another note, isn´t the tormek a bit slow?


edit: slowfor removing a big chunk of metal on the scraper?

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member of the guild of professional dilettantes

Big chunk as in "that thing is thick"! But, thinking again you should just have to grind the edges of the hollow, so i guess it's no biggie.
You're spot on on the price Filippo!

Cheers,
Miguel.

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member of the guild of professional dilettantes

Anybody know the radius of the stone used to make the original grind?

Mike

Don't know but mine is 8" and I for sure did not remove very much metal.

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Steve Smith
"Music is what feelings sound like"

I don't know what radius they used, but it really does not matter. You can use a fairly tight radius, or make it flat: the thing will still work. I often touch mine up by lapping the faces to get the burr off, and then standing it up on a diamond stone to dress the edges. This gives a small, sharp burr which is really nice for final scraping, or for use on soft woods. This is what I use for the final surface on violin family stuff; no sanding. It has the added advantage of giving you a really straight edge, which makes a good guide the next time you do grind it.

Alan, since you've chimed in, what grit do you use when you diamond-stone the scraper, if I may so ask?

Thanks,
Miguel.

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member of the guild of professional dilettantes

mqbernardo asked:
"...what grit do you use when you diamond-stone the scraper, if I may so ask?"

The red one? It's either medium or fine, and the one I use for that is old and worn, so it's really pretty fine. Again, I'm not sure it matters a whole lot, except that the finer stone will probably give you a nicer surface.

Red one is Fine or about 800 mesh (25 micron).

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Steve Smith
"Music is what feelings sound like"

thanks guys!

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member of the guild of professional dilettantes

I'm hunting around for a new wheel for my bench grinder. What would you reccomend? Alumina Oxide? 150 grit?

Mike

150 grit is way too coarse for putting an edge on metal... i'd say 6-800 at the coarsest

Finer is probably better but the wheel I used is the one that came with the grinder - 120 grit. Sharpened it just fine. Based on Al's comments I'll probably try the diamond stone next time.

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Steve Smith
"Music is what feelings sound like"

seriously? Have you looked to see what is available out there? 150 seems to be on the high end.

I'm looking for a 12,000 micro mesh wheel. Plasma is out of my range.

well not many people do final hone on knives and chisels with 150 grit, and the edge of a scraper shouldn't be any different in principal.....the rough grit should leave a grooved, comb-like, furrowed finish. if you're just removing material, fine, but lots of people use scrapers to finish

I'm bumping this thread because I just had a chance to use my new scraper to scrape some binding. This thing is awesome! Anyone who doesn't own one, needs to go buy one now. Who knew scraping binding could be so fun!

Agreed, best purchase 2013 so far!