When will Larrivee use this way of construction?

[Matthew Larrivee]

Jean's first guitars had the internal back strip as mentioned. I believe he used it somewhere through to about 1983-84. If I remember correctly it stopped when we moved to North Vancouver. At the time the strip did serve to reinforce the back because we had a decorative strip of purfling down the center seem. When that purfling strip was removed from the design, the mahogany re-enforcement was no longer necessary.

Fast forward to 2007 when we made the JCL re-issue guitars... We put the re-enforcement strip on these guitars because we added the purfling strip again. We looked at it and realized we liked the look of it inside the instrument and so we decided to put the strip on all of the glossy guitars in the California shop. The Canadian shop also puts the strips on -05 series and up guitars but does not put them on -03's because of the added cost involved. We do sometimes add the strips to special run -03's that we make in California.

The strip is mostly decorative – It does help somewhat on extremely oily woods, but really the center seam join we do is so strong that it is un-necessary.

[Danny]

  Thanks Matthew

[unclrob]

Matt not to make trouble but if it serve's no real purpose why do it.I understand that certain woods need it or if your recreating something from the past but if you don't need it?
Oh and thanks for straighting us out.

[olchip]

  Errr, I didn't mean to step on anyone's toes, if that's how you felt reading my post, dependan...
The irony wasn't in any way pointed at the reader, but the author of the book, who obviously must have taken some loud mouth's story for granted and didn't bother to check it out, or have it proofread by anyone knowledgeable enough to pick it up. (Or totally mistook the guy's meaning)
And what gets to me is that we wind up with all kind of crazy stories about who did what and this influencing the sound of that which makes it even more difficult getting REAL, accurate and useful information.
A perfect example is the infamous Stradivarius "secret varnish ingredient/method" that got people going on and on for centuries. Thank god science finally put a lid on that one. The guy was a genius builder who mastered his trade and made exceptionnally good violins. And today, (like yesterday and the age before) some builders make some instruments that sound just as good, if not better than some of the stradivarii, but they don't match his regularity in quality production apparently, and certainly did not have a communication/financial frenzy launched on their brand.
On the net, I tend to be very cautious about info I get, and funnily (or rather stupidly) enough, not so much with books, I guess because there is (or should be) a process of editing going on. If it weren't for a guitar-making training I'm undergoing, I wouldn't have doubted what that author claimed myself!
Hence the irony... so again, let me apologize if you took it wrongly,
kindly, olchip

[olchip]

  Very interesting Matt, thanks! Two questions, if I may:
-do you only use mahogany for your strips, or do you also go for spruce?
And if the strips are no longer needed to keep the plates together, they still rigidify the back, but to no noticeable difference on sound, correct?

[ducktrapper]

How nice to hear from one of the chief "knuckleheads". And about those 03 baritones? Seriously, Matthew, I can't wait til Christmas! Too bad my darn car just cost me the price of one, now.  

[Matthew Larrivee]

Matt not to make trouble but if it serve's no real purpose why do it.I understand that certain woods need it or if your recreating something from the past but if you don't need it?
Oh and thanks for straighting us out.

It's just a design thing. Abalone isnt nessesary, but we use it because it looks nice. The volute serves no purpose any more, but people still like it

[Matthew Larrivee]

Very interesting Matt, thanks! Two questions, if I may:
-do you only use mahogany for your strips, or do you also go for spruce?
And if the strips are no longer needed to keep the plates together, they still rigidify the back, but to no noticeable difference on sound, correct?

Mahogany only, and no noticable difference on tone. Has about the same impact as going from maple to rosewood purflings

[unclrob]

Thanks Matt.

[jeremy3220]

oh My!
Well actually, it is a joint reinforcement called a back graft

Another common name is center joint reinforcement strip.

And if the strips are no longer needed to keep the plates together, they still rigidify the back, but to no noticeable difference on sound, correct?

These strips almost always have the grain running perpendicular to the back seam/grain... like all grafts do because it's much easier for the wood to split along the grain. However, this means that along the length of the strip it is very flexible so it doesn't add much stiffness.

[olchip]

yup, agreed... Thanks for pointing that out, because thinking back on it, I realize I was actually wondering about the amount of extra stress to the back joint induced by the curvature to the back. Sorry, I'm having difficulties phrasing this.. lol
Er,  if the back is bowed both lengthwise and bout wise, it should add stress to the joint, hence the idea of a back graft. Apparently, that extra load isn't of actual concern for the guitar maker (in this thread we've got examples of guitars w/o the graft that are 20 years+ old and are doing fine and passed the test of time).
Is it because the glues we use today are more efficient than before, or just an "overpreventive" measure implemented by classical luthiers? (which I completely understand considering the width of the plates and gluing surface involved, it's rather scary to leave it as is....  )

Matthew for your answers, it's a privilege to get your point of view on this...

[jeremy3220]

The arch in the back doesn't add any stress that we have to be concerned about. It's a gentle arch and it dispersed over the whole back.

And modern glues don't hold any better than HHG. The CJR strip is just preventive in case the glue doesn't adhere as well as planned... like a bad batch of glue, oily wood, or a purfling strip that doesn't hold as well.

[olchip]

  thanks for the answer! Another choice to be included in my next guitar!!!

[wswl]

Thanks Matthew!!!  So nice to have you telling us the answer

I prefer not to add that stripe, as I want to see a flat and beautiful lable, just like the one on my D-50E.