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Anyone out there using or making Fox type kerfing (kerfing strip with cap strip)?

I'd be interested in picking some of it up to try out if anyone is making it!

Thanks,

Paul Woolson makes it.

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Lance@LuthiersForum.com

Russ, I don't have any for sale, but I am getting ready to try it out. I saw the design while at Charles' class and it seems to be a pretty cool way to do it.

It also has the advantage if making the sides very stiff. Once the linings were glued on he did all the rest of his work outside the mold.

I'll try to remember to post some pics once I get around to trying it out.

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Dave Rector
Rector Guitars

Hey Russ, I've got some. I haven't made it in awhile so I don't have a ton. How much are you looking for? What material are you looking to have it made from? You can either email me or pm me if you wish. Paul
paul@woolsonsoundcraft.com

Paul,

I dropped you an email about this...but forgot to mention materials...I prefer to use cedar (for that cigar box smell!) but I am open to others.

Maybe a mix and match...cedar kerfing, spruce filler strip......always getting carried away! :)

Thanks,

Kind of off to the side ... when I saw that lining method on the web, I thought it was a nice way of going - it should make the rims nice and rigid compared to regular linings. I used them on my current instrument, it does. There is a school of thought that believes good and rigid sides are beneficial to tone, so all the more better.

But, I had a discussion with Mike Doolin regarding the Fox style linings (Mike has never tried them), and he brought up the point that if they're more rigid, then the top is more rigidly attached to the sides. He thought that this would effectively reduce the vibrating area of the top by some small amount, which is contrary to common goal of maximizing the vibrating area. Mike got me thinking, and from an engineering point of view, I think that effect is a valid consideration.

Whether it actually makes an audible difference, is another matter. I suppose some testing would be in order. Since we all know the difficulty in building "identical" guitars, the effect of the two different lining methods would have to be evaluated over a relatively large sample of instruments built in an identical fashion (except for the linings of course). I love to test stuff, but if you leave it up to me, I'll have some results by the year 2048 maybe?

Pete

P.S. For the work involved, if I do use reverse kerfed linings again, they would be "regular" reverse kerfed linings which have the same stiffening effect, but without doubling the work by requiring the intallation of the thin strip after the linings proper are installed.

Think about it ... the only difference between assembled and installed Fox style linings and "regular" reverse kerfed linings, is the thin 1/32" web that holds the Fox kerfs together prior to installation. This ends up between the linings and the sides, practically at the neutral axis, so it doesn't contribute to the stiffening effect. That thin web does superficially increase gluing surface, but I've found when you break the linings usually the web splits off from the bulk of the lining. In light of that, I don't think the gluing surface is the limiting factor in any way.

In the end, I don't think the extra (marginally or not useful) gluing surface is much of a selling point when you consider it's double the work to install the extra strip used the Fox style linings. Keep in mind that with "regular" reverse kerfed linings, the thin web that holds the kerfs together is installed away from the neutral axis, so there it does provide stiffness and rigidity, and all in one step.

So what more can possible be said about linings????

Pete - you're right, plenty has been said about linings, but what more to say?

Here is some food for thought. Many classical makers (myself included) use small blocks to glue the soundboard to the sides, which are spaced about 5mm apart or so (I've seen bigger spaces). This makes the periphery somewhat more flexible.

Ramirez and Friederich (et al) favor an extremely stiff side (double sides, actually) and a very rigid box construction in order to isolate the soundboard for sound production. The sides seem to average around 4mm thick, and create a heavier structure.

Torres on the other hand, made his sides around 1.0mm thick, sometimes a little closer to 1.5 but not much, and used mostly kerfed linings like we use today.

There are a lot of different approaches in making a guitar, but I tend to believe that making the sides extra stiff helps mostly in the construction as opposed to the sound.

best wishes,
Joshua

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Instagram: @jfrenchluthier
Web: https://www.jfrenchguitars.com/

OK so I have to ask, what are Fox Style Kerfings??

J... Those are called Tentallones and I use them on all my classicals because that's what alot of the great builders did...

I also integrate my side braces into the kerfing (like they do for archtops)..

Cheers

-Paul-

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-Paul-

Patriot Guitars

http://www.frets.com/FRETSPages/Features/CFox/cfox01.html

Pete, you bring up a lot of good points and yes, too much has been hashed out over these linings. BUT...I'd have to disagree with Mike over the stifining of the top. Because the thickness of the linings is actually less than that of standard wedge shaped linings. Thus less of the top is glued to the linings allowing it to move more freely. Yes, it's minimal but is probably measurable if one was so inclined to do so.
I'm in the "rigid back and sides" camp. My friend John Watkins is in the "build it as light as possible" camp. Two completely different ways to skin the cat yet we don't notice any significant differences between our guitars. (Yes, they are very different but we can't attribute a "certain" difference due to that particular difference in building).
For me the linings are worth the effort for two reasons.
1) the stability makes the rim workable before it is made into a box. Sanding profiles without a mold is very convient.
2)I like them over reversed kerf linings because you don't get glue stuck in the kerfs. Yes, it's in the inside of the guitar where it doesn't matter but to me, it does.

Paul,

BUT...I'd have to disagree with Mike over the stifining of the top. Because the thickness of the linings is actually less than that of standard wedge shaped linings.

I hadn't picked up on the nuance that they're thinner than standard. Gee, I wonder what I made mine? Probably the same as standard since I didn't know they were thinner. If they're made thinner, then I agree this would be a mitigating factor for losing effective vibrational area.

I like them over reversed kerf linings because you don't get glue stuck in the kerfs. Yes, it's in the inside of the guitar where it doesn't matter but to me, it does.

Well, we're of the same wavelength there. Frankly I hadn't thought of that (yet), but once I saw the ugly globs of glue stuck between the kerfs, I would have frowned and thought to myself "Hmmmmmmmmm ..."

To mix the stew a little more...how about using the stiffer "Fox style"
lining on the back to sides junction and a more conventional kerfed lining
on the top to sides junction?
My seat of the pants thought (no hard evidence) is that a more giving
top/sides attachment would dampen less. That being said, some of the
best sounding guitars I've played were Fox's...
-C

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Freeborn Guitars
and home of BeauGuard©

Chas, it's a non-issue. As I said before, they are thinner so the relative stiffness to the top is actually less. The stiffness is lateral which really only effects the sides.

Chas,

Actually, I used them on both the top and the back. Someday this century this instrument might just be finished.

I'm of the belief that the back coupling to the top can help the tone production of an instrument, and I would guess that having stiffer sides may make it easier to control the coupling. In other words, "mushy" sides might bleed off energy or couple it in unpredictable ways. Al Carruth would know this better than I.

Yes, I too use them on top and back. I don't see any advantage to changing them to standard linings on the top. Mine are less than 1/4" thick which is much thinner than some of the wedge shaped linings I've see. Pwoolson38415.6303819444

First off, great looking work!

But how the heck did you get that huge picture in there? It took me forever to keep shrinking mine until it finally didn't come back with the message that it's too large. Even when my computer said it was several KB under 35K, it came up over the limit by the time it got to the forum. So what's your resolution and size above?

Wow, that's obnoxiously huge. the pic is actually hosted on my site rather than downloading it here. If you have that capability, the third button on the right (the tree without the arrow) will allow you to link to off-site sources.

Aahhhhhh, that's what you did. Well, since I have no site, guess I won't be using that button. Thanks for the answer, though!

I'll add another ingredient to the pot. Why not just use veneer strips around the top and bottom of the shell to add stiffness to the sides? I've read that someone does it this way but can't remember who (maybe Rick Turner).   

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Don Atwood
Arlington, VA

Geeze Woolson....

Are you even human?? that thing is awesome

So what are the dimensions of the kerfing, if you some for sale I'd like to buy 4 pieces to give it a try and see how it works. I might have to end up switching to that

Cheers

-Paul-

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-Paul-

Patriot Guitars

I am constantly amazed at the helpful attitude of the members of this forum...an email to Paul, and he offers to go out of his way to help me with these kerfings!

Great group of people here!

Paul, If that was my guitar I'd never put a top on it, I'd just hang it on the wall as the work of art it most certainly is. Sometimes this forum is can really depress a chap! I can't even imagine that one day.......

Colin

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I don't believe in anything, I simply make use of a set of reasonable working hypotheses.

Guys, relax, it's just a guitar. And I'm just a builder. I make just as many mistakes (check that, probably many more) than all of you. To prove it here's a story about this one:
I put a douglas fir top on this as an experiment. Very crisp almost brittle tap tone. I thought is would be nice for a big guitar. As I was sanding the top (already on the guitar) with my RO sander, I got into a pitch pocket. So of course it tried to chase it out. Long story short, that made the top .040 just below the bridge. I'm thinking that would be a disaster waiting to happen so I cut the top off and put on a sitka top. All was good and I went to bind when my router slipped off the top surface and cut down an extra .060 in depth. HMMMMM, well I guess I'll put on taller bindings. So I wanted to even it up to the depth of the mistake. And the router slipped again in another place (I've since rebuilt my binding jig due to this experience). Now I've got bindings that are almost .400 tall and looking really funny. I went to sand them and realized (I used Padauk) that even though I sealed them prior to installing them, they stained the maple very badly. So I routed them off and in the process cut too deep the third time. The guitar now sits unfinished on the shelf of guitars that sit unfinished but I haven't the heart to throw them away.
Moral: heck, there is not moral, I'm just a sucker trying to make it in this biz like everyone else. I just know when to post the "good" photos.
Paul

Don A.: there are lots of people that use solid linings. They can look really nice in my opinion. But I think they are a LOT of work. And they probably ad about 50% more weight than kerfed linings. (Maybe even more)
Paul: they are 1/4" x 1" tall. The height is what really "locks" in the stiffness to this whole sandwich thing. I'm experimenting with some different blades that don't chip out when I cut the kerfs. When I land on something I'll let you know and see if you want some then. For some reason I'm busy building clamps at the moment. ;^)

Paul, what I was trying to describe,poorly I should add , was just a veneer band glued to the sides as a reinforment around the top and back. The kerfs are then glued to the band, either standard or reversed. I guess the best way to describe it would be semi-laminated sides. It wouldn't improve the inner box appearance but would provide extra stiffness. I wish I could remember for certain who does this, but I'm still drawing a blank.    

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Don Atwood
Arlington, VA