Official Luthiers Forum!

Looking for help...again

Closing the box up tonight and it crossed my mind that I'm not sure which
channel to route first, the binding or the purfling?
Does it make a difference?
I will be using the Ribbeke set up with Stew Mac bits if that helps answer my
question.

Thanks,
Chris

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Christopher C. Cordle
North Muskegon, MI

http://www.yardsaleunderwear.com
http://www.facebook.com/christopher.cordle

LMI bits...purflings first. I'm not sure if I makes a difference as long as the bits/bearings allow for either first. Check to make sure your bits allow either first or plan accordingly.

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JJ
Napa, CA
http://www.DonohueGuitars.com

If you are using the Stew Mac bearing guided bit you will need to cut the purfling channel first. Otherwise the bearing will fall into the binding channel when you try to cut the purfling.

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Dave Rector
Rector Guitars

Yep! Route the purfing channel first....

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Peter M.
Cornerstone Guitars
http://www.cornerstoneukes.com

[QUOTE=Hesh1956] great minds.... [/QUOTE]

Hey, speak for yourself there buddy.

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Dave Rector
Rector Guitars

Thanks guys,

Purflings it is!

One more thing.... I bought the purflings that are the same depth as my
binding thinking I could make a single cut. After thinking about it, it seems
that the combo of the purfling and binding would completely take away the
side and cut into the kerfing. Am I correct in my thinking?
If so, then why do they even make purfling 1/4" deep?
I'm thinking maybe I'll tape them down and cut them in two with a straight
edge and a razor blade.

_________________
Christopher C. Cordle
North Muskegon, MI

http://www.yardsaleunderwear.com
http://www.facebook.com/christopher.cordle

No definitely dont rout purfling and binding channel to same depth...youll watch you top neatly drop into the box.

Some tips.

1. Before doing the route do a test cut on scrap and check purfling and binding fit in the test channels.

2. Watch cut direction if using a router...see Stewmac website for instruction sheet on same.

3. I like to go arond with a gramil before doing the routing...makes for a cleaner cut.

Cheers Martin

You mean they actually have purfs that are .250 thick???

Hesh, it's true, the LMI cutter has the bearing a bit further than the Stew-Mac cutter... Still, after having the bearing ride into the channel on no.1, I have become extremelly paranoid about this and I always route the purfling channle first, regardless of the cutter I'm using...

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I'd like to be able to prove, just for once, that money wouldn't make me happy...

[QUOTE=Hesh1956] Chris the same depth or width as your bindings - I am
not sure I understand the question.[/QUOTE]

The same depth. It is B/W/B purfling with a 1/4" depth. Widt is 20/10/20.
When I bought it I was thinking "cool, one route could do both the purfling
and binding". Pretty sure that ain't gonna fly. Just wondering why they would
even make such a product.

_________________
Christopher C. Cordle
North Muskegon, MI

http://www.yardsaleunderwear.com
http://www.facebook.com/christopher.cordle

Here's a link to the purflings I bought.

They are the 4th one down...laminate black/maple/black 34.5" x 1/4" x .050

http://www.alliedlutherie.com/binding.htm

Others offer this too so I'm not trying to step on one particular vendor's toes
here. Just wondering what purpose this product serves.

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Christopher C. Cordle
North Muskegon, MI

http://www.yardsaleunderwear.com
http://www.facebook.com/christopher.cordle

[QUOTE=uncleshish] [QUOTE=Hesh1956] Chris the same depth or width as your bindings - I am
not sure I understand the question.[/QUOTE]

The same depth. It is B/W/B purfling with a 1/4" depth. Widt is 20/10/20.
When I bought it I was thinking "cool, one route could do both the purfling
and binding". Pretty sure that ain't gonna fly. Just wondering why they would
even make such a product.[/QUOTE]


YEOW! A quarter inch deep purfling? Couple that with the width of your binding and you MAY seriously compromise your kerf lining. Ideally a purling should be in the .060 to .080 thickness. That way it will still leave the full top-to-kerf glued contact patch on the lining. And with a nominal .080 to .100 binding, you will cut away little or none of the side glued face of the lining...assuming your sides are in the .090 thickness range.
As for uses for the quarter inch tall b/w/b...you could bind your fingerboard and/or headstock with it for an interesting effect since both those areas back up to solid wood.

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Hank Mauel

    If I'm understanding the question correctly, I'm assuming that you're
talking about you side purflings...not your top purflings so here's my
method and reasoning for the process.

    My sides are .080" or thereabout in thickness and my bondngs and
purflings are around .065". I cut the ledge for the binding and purflings
to te same depth since they will never cut through the sides. If you do cut
through, you run much more of a risk of glue squeezing through and into
the openings in your kerfing. A pretty sloopy prospect to say the least.

   My kerfing is .625" high and with the additon of the top thicknes of
about .125" or so, the total amount of supported side where the
bindings/purflings will end up is about .750" or 3/4". With the .250" high
bindings and the addition of the .062" side purflings, that only gives a
total of .312" or 5/16" so there is little chance of the top being cut
off....unless you're using very thick bindings and purflings.

   I cut my binding ledged first and then continue it for my purfling on the
sides. This allows me to lay the binding into the slot and test the purfling
cut depth to be sure that the binding reaches the butt wedge and binding
cuts at a florentine cutaway while allowing good tight purfling fit and
miter joints.

    The last thing I do is to cut the top purfling ledge, but I never use the
bearing guided cutters. I use a cutter sustem that has a laminate trimmer
mounted in a rise and fall unit and a depth and width control set of
bearings that allows me to register off of the side below the binding ledge
cut. It is my original prototype for the system that works so I never
refined or replaced it as I'd intended. Those who have been to my shop
know that I'm an old school guy who is more about function than
appearance when it comes to jigs and fixtures.

     This is just my experience through the use of my dimensions and
tooling. I've cut binding and purfling channels on more than 450 acoustic
guitars using this system with great results. I'll break 500 instruments in
the next year as i get back to work.   

Regards,
Kevin Gallagher/Omega Guitars

Chris, I think you bought some general purpose strips that are not specificly made for purfling. I purchased some b/w/b that was about .080.
One could route a larger binding channel if they used reverse linings.

Kurt

    Those 1/4" high purflings are most likely made for laying inside of
binding of a fingerboard. There's no way to make those work laid up with
body binding.

     I missed the post containing the depth of the purflings. Depending on
your method of gluing, you'll have tp carefully decide whether or not it's
safe to break through the sides into the gaps in the kerfing.

     If you use a conservative amount of glue and install, you'll most likely
not run into trouble, but if you apply glue liberally and depend on a good
amount of squeeze out when you pull the binding tight, the glue will
queeze in through the gaos and give all kinds of very visible sloppiness
inside.

    If you use Charles fox's CA technique in which you dry install the
bindings and purflings and then drip the thin CA into the gaps aallowing
to wick in to adhere them all and fill gaps, you will have and absolute
mess as the glue runs in and all over the sides, back and top.

Regards,
Kevin Gallagher/Omega Guitars

I bought full height (.250) purflings for my current guitar also, but after looking at the situation decided to use a shorter- .085"- purfling. My confusion, and perhaps Chris' comes from the "Bold Multi-Line Purfling" page on the LMI website. They show a cross-section picture with a purfling the same depth as the binding. But on looking at the picture carefully, the binding + purfling thickness is the same as the side. So what they are advocating is a laminated binding consisting of the outside binding wood laminated to a b/w/b inner layer the same depth as the thin binding. Is this confusing??? Look at the LMI website.

_________________
Gene

Politicians and diapers must be changed often, and for the same reason- Mark Twain

Ah, so. Picture worth 1000 words.

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Hank Mauel

[QUOTE=Hank Mauel] Ah, so. Picture worth 1000 words.

[/QUOTE]

Hank,

The proportions on the picture look as though it is for plastic binding. With the wooden bindings I use, the binding is as wide (or marginally wider) than the sides and the purfling thinner.

There is an interesting debate on the APM Forum about purfling and wood v plastic bindings on sound. Like Tim and Matt I hear a considerable differenence in sound from the box when it is closed compared to when the bindings and purflings are routed for and glued on.

Chris,

I route the binding channel first and then the purfling - I like to make sure I have a perfect fit for the binding before I cut the purfling. The adaptation I have of the Fleischman-Williams Binding jig means I can do it this way.

_________________
Dave White
De Faoite Stringed Instruments
". . . the one thing a machine just can't do is give you character and personalities and sometimes that comes with flaws, but it always comes with humanity" Monty Don talking about hand weaving, "Mastercrafts", Weaving, BBC March 2010

Dave...

Yes, the diagram is just for reference and a wood binding would be darn close to the same width (thickness) of the side.
The quarter inch stuff referred to in this thread was .050 thick if I recall. It "could" be used as a binding and that would give you a laminated look as seen from the face of the guitar.
However, if that quarter inch stuff was routed in for a true purfling, you can see how it would compromise the kerf integrity.
As you mentioned, once the purfling channel is cut there is a change in top resonance...due to the increased flexibility afford the edge of the top when material is removed. Traditional thinking was that herringbone, which presents a fairly wide purfle, removed more top wood and freed up the top for more "speaker cone" movement. The same could be accomplished by making a wider purfle channel to hold multiple plies of inlay or even a wide single piece of wood which would present a wider inlay when viewed head-on. The key here is to increase the tops "flexibility" at the rim while not compromising the glued surface against the face of the kerf lining. So, herringbone, per se, is not the reason that a herringbone purfled guitar "seems" to be more resonant/louder/etc.

Alternatively, if you wanted to do an unbound or no-purfled instrument, you could reduce the face width of the top kerf edge and achieve a similar outcome.

_________________
Hank Mauel