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I have a question the top's lining thickness.
For those guitar with heavily decorated purfling, say maybe over 8mm to 10mm in width.
Does the top's lining have to be wider to strengthen up the top's area underneath the purfling?
Or it doesn't matter since for the purfling rabbet we don't cut the top all the way thru' to the lining?
If the lining has to be wider, won't it affect the sound since the surface area of the top has reduced.

Take a look at this Torres copy of FE08 by luthier Brian Cohen.

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Sen CL Goh
http://senguitar.blogspot.com

I'm puzzled about this too when it comes to a real Torres like FE08. He made very thin tops of about 1.5 even less towards the edges so it is pretty tricky to inlay at half depth. On my last couple guitars I made wide purfling and I made them about 1.5mm deep with the spruce being about 1.7-1.9mm thick at the edge. I don't think the lining (standard 5.5mm) overhangs the purfling by much, max 0.5mm. I plan to cut my own lining next time and make it 1mm wider though. I think Romanillos' glue blocks are 8mm.

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Build log

I read somewhere that Francisco Simplicio used a shaped lining block (see drawing below) to save weight and to provide adequate support for the extra wide purflings often found on his guitars.

8 mm is right for the Romanillos blocks. That's what I've been using. It works fine to have top purfs in the 4 mm range and still have 4 mm of top attached. My tops at the edge are usually in the 1.5 to 1.9 range depending on the wood, and I usually end up cutting most of it away when doing the purf ledge.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Look at the FE08's purfling the width could easily be like 15mm?
The lining width could hit almost 20mm...

Here's another pic of Agustin Barrios's guitar.
I think it's a guitar by Francisco Simplicio.
Look at the purfling scheme consists of inlaying MOP triangles between 2 darker purfling.



I really like those thick width purfling; sort of like highlight the outline of the guitar.

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Sen CL Goh
http://senguitar.blogspot.com

Another angle on the 'wider linings' theme...

A few months ago I had a very interesting and informative email exchange with Frederick Sheppard about a a couple of replica projects he'd completed after some extensive research/study of the originals. His workmanship is really breathtaking.
http://www.guitarreria.eu/g_fr_federico_sheppard_bs.html

I specifically asked about support for the wide purflings/inlays.
Federico responded:
"The guitar has a false double top 2mm wider than the purflings that
the actual top sits on. .............."
In other words, the top is doubled around the perimeter in that guitar.

Federico also mentioned that the interior workmanship on the originals was quite poor, but they sounded and looked very good.


Cheers
John

Now that makes sense, much more than 20mm lining.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

Well in a way it's similar to what David showed, just that it is laminated in the horizontal plane, right?

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Build log

John any chance that you know what sort of grain orientation the laminated perimeter will need to be in?
If it's the same grain as the top then we probably need another piece of big spruce to cut out the perimeter in the same grain direction?

In that case the 20mm lining or individual dentellones might be an easier option.

But if the direction of the laminated can be radial, then I think the double layered perimeter is an easier solution.

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Sen CL Goh
http://senguitar.blogspot.com

I'd just use an oversized piece of spruce for the top, and use the offcuts for the edge laminating. Just a little snipping to match the shape, and it would have matching grain direction. Although I can't really come up with a good reason for the grain to matter, with all those purflings right on top of it, and linings below part of it too.

I just found an article on Simplicio written by R.E. Brune.

http://www.vintageguitar.com/features/brands/details.asp?AID=3617

In one of the paragraphs, Brune described, "Internally, Simplicio used molded kerfed linings of cedar and pine, which ingeniously provided adequate internal support for the wide, elaborate external inlays and purflings without making the instrument noticeably heavier."

I guess he meant more of what David has described?

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Sen CL Goh
http://senguitar.blogspot.com

Now I remember where I saw it!
Indeed yes it was the Brune' artcle in VG mag.
Part of hs excellent "Guitars with Guts" series.

Just found a website on Barrio's Simplicio guitar.
It has wide purfling and inside the guitar, there is a 2nd layer of spruce to support wide purfling.
On top of the 2nd layer, Simplicio glued the dentellones.
The grain orientation doesn't seem to matter much for the 2nd layer.





The link to the website.
http://www.barriosworldwide.com/blog/en/?p=102

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Sen CL Goh
http://senguitar.blogspot.com

I suspect that it can be done both ways. Some Baroque and Romantic Guitars have very wide purfling schemes. They are all put on a half edge with either no linings or linings that are relatively thin.

I always cut through or nearly through the entire top thickness (2.3-1.8mm) to inlay purflings.
With a 7-8 mm lining width purflings like this come pretty close but there still seems to be enough strength so that there is no problem with stability. Any wider though would definitely require special blocks or the doubling mentioned above (though the doubling I think would require other adjustments to be made to compensate in the tone of the guitar).