Purfling Cutter

derekdarling · Post by **derekdarling** » Sat Dec 04, 2010 12:40 am

My wife's sister and her husband visited from Toronto last summer. Dave retired from the Toronto Transit Commission as a locksmith, and set up his machine shop at home. I believe the floor pad cracked under the lathe and he had to dig a new pad foundation! Anyway, while he was here, we talked tools, and I described a cutter that could be used to cut a channel for purfling; that's the strip that goes near the edge of a violin or guitar. Most guitars have edge binding, and a single knife would do, but for a violin, you want to have a nice channel to inlay into.

Dave went home, and made the tool you see in the attached pictures. The tool cuts the channel, I would still need to uise a small chisel to clean out the trough.

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End Detail

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Another detail of the business end

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And again, the business end

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Side View

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Detail of the knives

The knives are reversible, and there are spacers to set the distance from the edge guide, and the distance between the knives. The knives are X-Acto #24 blades, which are 'sharp one side' so the sides of the channel are straight. You (ok... I) could also use one knife to cut a rebate edge (rabet). The edge guide is also reversible, so you can cut one side or t'other and always cut on the pull. I have asked him to make another edge guide with a thinner shank to get into tight corners.

The bulk of the tool is brass, and the wood is walnut. I can't say enough about the skill and, well, the love that went into this tool. I have used it on some test pieces, and it cuts a nice channel with square sides.

Some people would think that using a dremel or small router with a sharp cutter would work just as well. Some people focus on the destination, not the journey!

Anyway, Thanks, Dave! And here's to brothers in law who are really good at what they do... and are free with their talents. I only hope that any instrument I make is worthy of this tool.

Derek in Vancouver, BC
(well... Surrey, which is close enough!)

nuhobby · Post by **nuhobby** » Sat Dec 04, 2010 4:18 am

Now that is an heirloom tool! Hope you have a great time with it.

I may contact your BIL for a pinstriping brush sometime;) .

burkhome · Post by **burkhome** » Sat Dec 04, 2010 6:36 am

Awsome story and beautiful tool Derek.

JPG · Post by **JPG** » Sat Dec 04, 2010 9:48 am

Tis a thing of beauty! The walnut really sets it off(as well as make it comfortable to hold). Yer BIL is an artiste as well as an excellent machinist.

Quite a competent innovator as well!

P.S. Amazing the things one learns on this forum! Purfling-Who knew what that was before this thread?

Ed in Tampa · Post by **Ed in Tampa** » Sat Dec 04, 2010 10:30 am

Really nice job!!!!

I have a question wouldn't a small (very small) hand held route with an edge guide do the job better? It would cut the channel and clean the bottom in one operation.

Perhaps it is Norm (New Yankee Workshop) versus Roy Underhill (Woodwright Shop) One uses power everything the other doesn't use any power other than himself.

JPG · Post by **JPG** » Sat Dec 04, 2010 11:20 am

Ed in Tampa wrote:Really nice job!!!!

I have a question wouldn't a small (very small) hand held route with an edge guide do the job better? It would cut the channel and clean the bottom in one operation.

Perhaps it is Norm (New Yankee Workshop) versus Roy Underhill (Woodwright Shop) One uses power everything the other doesn't use any power other than himself.

The journey Ed, The journey!:)

derekdarling · Post by **derekdarling** » Sat Dec 04, 2010 8:53 pm

The journey, indeed!

What I particularly like is that this tool has some heft to it. It is about 8" long, and 1 1/4" square at the business end. I used it a bit today on another test piece. It seems it works best to take a shallow cut, then clean out the groove, then another shallow cut, and so on. I'm not on piece-work, and if I don't actually finish a piece, the experience has already made my life better.

For those interested:
pur·fle (pûrfl)
tr.v. pur·fled, pur·fling, pur·fles
To finish or decorate the border or edge of.
n. also pur·fling (-flng)
An ornamental border or edging.
[Middle English purfilen, from Old French porfiler, from Vulgar Latin *prflre : Latin pr-, forth; see pro-1 + Latin flum, thread; see gwh- in Indo-European roots.]

So much for etymology:D

The purfling serves to strengthen the edge of the violin or mandolin plate, as well as being an opportunity to get creative. Very often, there will be several thin strips of wood or other binding material glued together, then inset into the groove. The purfling may also serve to seal the edge of the plate against moisture seeping in via the edge grain.

I'll ask Dave if he is interested in making custom tools, and I'll letyou know, off line. I don't know if he wants to start another business after retiring, but hey... you never know.

Derek

dwevans · Post by **dwevans** » Mon Dec 06, 2010 11:37 am

Very nice, Much prettier than the router jig I use to do the same job.

Gene Howe · Post by **Gene Howe** » Mon Dec 06, 2010 1:27 pm

That is one cool tool!

holsgo · Post by **holsgo** » Mon Dec 06, 2010 5:45 pm

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Here is a stanley 66 beading cutter that does the same cut but with a curved fence.

I have tried endlessly to embed a pic. Can someone straighten me out on that? (update, I've been teached!)