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Cutting the scroll on F-Style mandolin?
http://w-ww.luthiersforum.com/forum/viewtopic.php?f=10102&t=12063		 Page 1 of 1
Author:  sgriffith1962 [ Wed May 16, 2007 3:58 am ]
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Hello,  I am new to forum.  I am building my first instruments, yes instruments.  I am taking them one at a time, but have been collecting supplies for a mandolin, classical guitar and an electric guitar.


Brave (nieave) me, I started with the mandolin first.   I have already ruined one top while trying to cut the scroll.  I have Siminoff's book, and watched the DIY series.  But, I have some questions on cutting the scroll area.


1.  When cutting the top and back, I left about 1/4 inch extra around the outline shape.  When I got to the scroll,  I can't make the bandsaw curve sharp enough to accurately cut the scroll.  How do you do this?   ( I have floor bandsaw,  14", with a 1/4 inch blade)


2.  It seems to get the same shape, I might need to finish cutting the scroll after the assembly of the body.  Is this right?


3.  As for salvaging the "ruined" top,  the mis-cut is into the scroll.  Can I still make an "A" model mandolin?


 
Author:  Arnt Rian [ Wed May 16, 2007 4:35 am ]
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Hi sgriffith1962, let me be the first to welcome you to the OLF, you will like it here!

Not too many members here build mandolins, but I have built a few F's and A's. On the F's I leave the scroll "unopened" until the plates are glued to the rim. I use a jigsaw blade with a wooden handle on it to open the "strap holder" area, then clean things up with a small knfe and a Dremel.

Sure you can use the top with the ruined scroll for an A model as long as you didin't cut into the A body outline. The archings and shape minus the scrolls and points make and excellent A.

Here are a couple of pictures of a Dudenbostel mandolin before and after the scroll is opened (the funny thing attached to the underside the top is a "Virzi Tone Producer", one of the things that Lloyd Loar experimented with on the early twenties Gibson F5's)

Before:


After (you see the tools Dude uses for the operation in the picture, this was the inspiration for my jigsaw blade tool):

Author:  Matt Gage [ Wed May 16, 2007 11:14 pm ]
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Hey Arnt, I noticed that the Virzi is closer to the bass brace than the treble.

is there a reason for positioning it that way?
are you looking to add mass to the bass side?

I have made two F style mando`s but hav`nt had a chance to hear what difference the virzi makes in one.


Matt
Author:  Arnt Rian [ Thu May 17, 2007 12:07 am ]
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Matt, I have never played a mandolin with a Virzi, let alone built one so I don't know much about them or exactly where you want to place them. Many, if not most of the original Loars that had them installed originally have had them taken out. Loar experimented with Virzis in all of Gibson's Master Model mandolins, mandolas, and guitars, as well as violins and violas. Today some builders are makeing instruments with them, especially ones who specialize in Loar reproductions.

From what I have read a Virzi tends to make the instrument a bit quieter, which is to be expected with the added mass to the top, but since it is coupled to the top by two sometimes three "feet" in the middle of the disk, its rims are toatally free to vibrate, as opposed to the soundboard which is fixed to the sides along it's perimeter, and thus emits an entirely different series of overtones or "partials". Or so the theory goes.

I believe the mandolin in the picture was built for Chris Thile, so you can probably hear it in some of Nickle Creeks records!
Author:  Matt Gage [ Thu May 17, 2007 12:48 am ]
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Intresting, thanks.... i can see where it would warm up the tone some, especially if the top plate was very stiff.

I`m thinking they (Gibson) wanted to keep the tops more stable so
they may have left the tops a bit thicker but added the virzi to add bottom end to the tone with out thinning the graduation to much.

forgive me if I am way off base here, it could be the opposite of what I am thinking.


Matt

Author:  Arnt Rian [ Thu May 17, 2007 1:48 am ]
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You could be right, although I suspect that Loars "tuning of the air chamber" was not primarily done to avoid warranty issues; some of the Loars I understand have pretty thin tops. Sinking tops seems to be a more common problem with oval sound hole models, especially if the brace betweeen the bridge and the sound hole comes unglued.

One think to keep in mind is that the early '20's mandolins were intended for and entirely different kind of music than the bluegrass they became famous in much later; Loar hismelf was an accomplshied classical musican. A complaint some blue grass musicans have against the Virzi is that it takes away from the "bark" of the instrument.
Author:  rajones19 [ Thu May 17, 2007 2:30 am ]
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John Monteleone refers to the Virzi as the "Virzi Tone Reducer". He's worked on a lot of old Loars, and is NOT a fan of the Virzi's at all.

I've got links to a few other sources of mandolin-related information - is it appropriate to post links to other forums here?
Author:  Howard Klepper [ Thu May 17, 2007 2:41 am ]
Post subject: 
This is not the best forum for your questions. Check out the Mandolin Cafe.

The F-style mandolin is easily the most difficult of the standard fretted instruments to build--harder than an archtop guitar, lots harder than a flattop. I've only cut one f-style scroll. I bandsawed as far as I could go, and then used jewelers files and rasps. But cutting the scroll is a snap compared to binding it.

You done the headstock scrolls yet?

I actually found fitting the neck joint to be harder than the scroll work.

Good luck. Actually, luck won't get you there. You need to be a very talented craftsman to build a decent F the first time out.
Author:  sgriffith1962 [ Thu May 17, 2007 1:29 pm ]
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Thanks for the imput.  I'll check out the mandolin cafe site.  I have been there before, but did not realize they addressed building. 


As to wheither I have cut the headstock yet - no.  I am just now carving the top and back.  (my starting point)  I plan to do the neck next,  then do the rim assembly, etc.    I wanted to get the carving out of the way before I wasted some curly sides learning to bend figured maple.


I post pictures when I have something to show.
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