Radius on a tail block after adding a plywood insert?

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Rag Thumb
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Radius on a tail block after adding a plywood insert?

Post by Rag Thumb »

In one of John's videos he shows us how to modify a solid tail block by dadoing in a piece of plywood in order to prevent later splitting if the guitar is struck on the strap button.

I am wondering if it is important to do that in such as way that the slight radius on the tail block is maintained.

What I have recently done is made the plywood be a bit proud of the tail block and then use a hand plane and later sandpaper to try to replicate the radius. I know it's not perfect but it is probably pretty close. Is that good enough??

Not that I would have a way to recreate it perfectly anyway, but I'm wondering if that radius is important. I think later in that video John says that he ends up making the tail end of the guitar where the flat.
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Rex
tippie53
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Re: Radius on a tail block after adding a plywood insert?

Post by tippie53 »

I have done so many of these that I can eyeball that radius in. You can do it like I showed where I just sand it in then match it to your mold. The plywood will save the body if you ever drop it on your pin
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
phavriluk
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Re: Radius on a tail block after adding a plywood insert?

Post by phavriluk »

A few questions....(1) why use a solid piece of wood for a tailblock in the first place and (2) why use a tapered pin which if driven into that solid tailblock, will split it? Tailblocks can be made of birch ply, and screwed-in end buttons used instead of tapered end pins. Problem goes away. And, third question, why go to the extra steps of 'reinforcing' those easily split tailblocks when the whole exposure to damage is so easy to avoid in the first place?
peter havriluk
tippie53
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Re: Radius on a tail block after adding a plywood insert?

Post by tippie53 »

the strap pin is and was always tapered but you may use screw ons. Plywood blocks do work but most higher end use solid mahogany blocks traditionally.
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
phavriluk
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Re: Radius on a tail block after adding a plywood insert?

Post by phavriluk »

Thanks, John.
peter havriluk
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Re: Radius on a tail block after adding a plywood insert?

Post by ruby@magpage.com »

I have seen a couple of high end small makers use plywood at both ends. I glue the plywood on the face of the tail block against the sides, draw a vertical line up the center of the plywood face, put it at its spot at the mold and draw the arc on the plywood edge, then take it to the belt sander. I leave the center line, and the various plies allow me to shape it symmetrically. Depending on the shape of the curve (e.g. Gibson early 00 vs a Martin 00) I might remove a bunch of material with a hand plane first, again using the look of the plies to make it symmetrical, then the belt sander.

Ed
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bftobin
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Re: Radius on a tail block after adding a plywood insert?

Post by bftobin »

I saw Michael Greenfield is using birch ply for tail blocks on some of his guitars and they're in the +$20,000 range.
I think it's becoming more and more acceptable, just as ebony with grey streaks is. But one thing I can't seem to get used to is wood dealers selling 'firewood grade' as 'exhibition grade and charging premium prices.
Rant is now finished !

Brent
Rag Thumb
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Re: Radius on a tail block after adding a plywood insert?

Post by Rag Thumb »

Thanks everyone! It never dawned on me to use the mold as a template for the arc. I ought to be able to eyeball it from there.
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Rex
tippie53
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Re: Radius on a tail block after adding a plywood insert?

Post by tippie53 »

ply makes a terrible neck block as it just doesn't take glue well. Martin used it for M&T blocks and they let loose most of the time.
I use plywood on the tail blocks when I make them and I inlet a piece so you only see the Mahogany from the inside of the guitar
John Hall
Blues Creek Guitars Inc
Authorized CF Martin Repair Center
president of Association of Stringed Instrument Artisans
http://www.bluescreekguitars.com
Diane Kauffmds
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Re: Radius on a tail block after adding a plywood insert?

Post by Diane Kauffmds »

I can tell you from painful, firsthand experience, that the dado works.

I put dado's in all of my tail blocks. I dropped my Delilah smack on the cement floor. She had some damage, but nothing catastrophic, and none on her sides. I've repaired countless guitars now with huge side cracks from being dropped. I have no doubt that a dado would have prevented the damage.
Diane Kauffmann
Country Roads Guitars
countryroadsguitars@gmail.com
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