# Octaves, Zouks, Citterns, Tenors and Electrics > Tenor Guitars >  Trying something new!

## fox

I have been experimenting with end gain sides backed with carbon fibre.
This is no 2, better than no 1' hopefully no 3 will better still?

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derbex

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## Magnus Geijer

That's awesome! I love it when people try something different than the standards. Let us know how it turns out.

Thanks,

Magnus

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fox

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## fox

Thank you Magnus, I don't get much support from this forum but I thought the design might interest a few members!
I have made a few tenor banjo rims from end grain blocks, I always preferred the look to laminated rims, so I thought I would have a go at an end grain tenor guitar.
I have also followed the banjo theme buy making the sides quite thick, at around 3mm they are almost twice as thick as normal heat bent sides.
I have also discovered that buy using slow setting, high viscosity epoxy resin, the epoxy actually penetrates right through the end grain making the blocks extremely solid & permanently set in shape.

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## bruce.b

That is very interesting. I like the look. I also like the idea of making the sides thicker and stiffer.

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fox

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## OneChordTrick

Looks great! Like Magnus I appreciate it when someone is not afraid to go against the grain.

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fox, 

hank

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## Dolamon

Great idea Fox. Did you have to do the heat curing routine for the carbon fibre to become rigid enough to support the end grain laminates? I recall some of the problems which Rigel went through and have personally had problems with aerodynamically shaped masts for ice boats. They both required special 'baking' before they were structurally sound and not like limp spaghetti. A home made sixteen foot long oven is a sight to behold.

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## fox

No, just ambient temperature (around 22c) It has not been as easy as I hoped it would be but, I have a system now.

Once I have cut the pieces I lay them out on some sticky tape, then paint the end grain surface with warmed epoxy & quickly set the tape with wood attached into a female mould. It is then a matter of pressing the male mould down with four large clams & letting it set for 24 hours.
I then remove the male mould & the tape, then apply two layers of carbon weave & epoxy. Finally I use a slightly different male mould (.75mm smaller) & clamp that down with as much force as I can.
At that stage I have one side complete & very ridged, so not a quick process compared to using a heating iron and bending wood.
A much simpler way would be to use three .6mm veneers & back that with carbon but then it would just look like any other guitar you can buy.

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## Tim N

I like the look of it.  It gives a sort of tortoiseshell look that is really different. Would it be correct to say that whilst celebrating the woodiness of the materials, it becomes more a question of aesthetics rather than of the tonal qualities of the wood? Or is that relatively irrelavent with the sides anyway? What kind of wood are you using?

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fox

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## CES

Looks really cool! What are you going to use for top and back wood?

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## Beanzy

That's going to be a very classy guitar.

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fox

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## fox

The wood is Camilla, I have been lucky with wood as I am friends with a landscape gardener who maintains several stately homes.
As a keen didgeridoo builder I have quite a selection of branches & smaller trunks, some are quite exotic.
The 200 year old Camilla in question has possibly the most spectacular colours, lots of red, green blue & yellow but I also have lots of other hard woods to choose from.
The top & back will most likely be Monterey Cypress but I only have enough left for one more guitar so I want to make sure I make a body worthy of the Cypress!
Anyway I have made another attempt at an end grain side that is ready to come out of the mould this morning, with a bit of luck it will have tighter joints & look even better....

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## fox

I though I would share some of todays woes.... after another 9 hours in the shed & I am still not satisfied with the results I am achieving!
This is meant to be fun for me but my stress levels are overflowing.  :Crying: 
I want to have a perfect finish out of the mould, the mould surfaces are lined with formica ( I think you call it something else in the States) The formica is highly polished, the idea is that the end grain will have a coating of epoxy that has a perfectly flat finish but, I am getting low patches and a dull finish in other places. I think this is due to irregularities in the formica  & a non perfect fit between the two mould halves.
I also think the end grain sucks up the epoxy so much, that I am not using enough to totally saturate the wood
So today I relined the mould with 1mm polished stainless steel & made another side!Unfortunately I now have to wait  12 hours to see if this will give a better result.

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## Denny Gies

Pretty neat, you are sly as a fox.

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fox

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## fox

This really is not easy, I have concluded a few facts though.
The 3mm thick end grain pieces I have been using are very porous, to such an extent that they suck up huge quantities of epoxy.
This means several things to me... one is the wood becomes totally saturated & in effect becomes more like moulded plastic than bent wood. I don't think this is a bad thing as the result will be extremely durable & wont be effected by moisture ( or hardly anything else) but the issue is the weight! I would guesse  the sides would weigh at least 3 x more that a standard wooden side.
I would think that the type of wood used will make a big difference as to how much epoxy it would absorb, I could just use a tight grain wood.
On a positive note, the last one out is looking amazing... just very heavy!

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## derbex

Hmm, if the wood soaks up that much epoxy do you still need the CF layers? Can you go any thinner on the wood, although 3mm seems pretty thin already.

Still at least you'll be able to use it club an unruly audience!

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## Beanzy

How about using shellac as a sealant followed by a thin layer of epoxy to bond it?
You could even stay with the theme and go for a french polish finish on the outside.

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## fatt-dad

Isn't there some trick with scrambled egg whites?

(I'm no builder, just curious. . . )

f-d

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## fox

Yeah thanks guys there are a few ways to go...
I do want thick dense sides, I like the speaker box concept, the carbon weave really looks cool on the inside so I could use a thinner wood veneer & add an extra layer of carbon.
I am probably going to carry on building the prototype as I have other interesting ideas to test out.

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## fox

By George l think I have cracked it!
After  many exempts and useing the very last of my camellia wood, I have managed to produce a good result.
I changed from slow setting epoxy to fast setting and added a thickening agent, I used 2.5mm pieces of end gain and two layers of carbon.
So I now have one side finished and one setting in the mould & a lot of not quite perfect sides LOL.

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## Magnus Geijer

Eh, weight is overrated anyway. This thing is probably my favorite of the ones I've built. Of course, it's electric...

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fox

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## fox

This mornings work straight out of the mould....

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Jerusalem Ridge

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## derbex

That does look the mutt's. Reminds me a little of a fossil bed.

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fox

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## Tim N

Looks amazing!

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fox

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## fox

Not much progress this week, but I have fitted some square carbon tube (round inside) as body bracing.
I have set the the sides slightly askew... just be different....

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derbex

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## fox

A bit more progress, I have just enough Monterey cypress to make a one piece top and a one piece arch back.
I had to cut the wood by hand then I planed the top down to 2mm, I have used a nice piece of mahogany for the sound hole area.
Also started the neck....

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OneChordTrick

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## derbex

Another interesting design -looks good.

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fox

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## fox

A bit more done...

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derbex

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## fox

The arch back in progress...

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colorado_al

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## derbex

Looks better than good now, I am not sure if it's an instrument or art, probably both.

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## fox

Thanks mate, I am just making it up as I go along but it has taken me well over 150 hours so far. 
I made a V neck profile and I don't like it so it feels like I need to make mother one now!

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## Tim N

That looks amazing! You've got to call it "the tortoise" now. It'll be interesting to see how it sounds, compared to a traditional build - but it's certainly art, and no doubt, very _you_ .

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fox

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## derbex

> Thanks mate, I am just making it up as I go along but it has taken me well over 150 hours so far. 
> I made a V neck profile and I don't like it so it feels like I need to make mother one now!


Neck profiles are funny things, my instruments vary from quite a deep V on the bowlback and tenor banjo -neither of which have a truss rod- to a shallow U on the Buchanan OM. The profile doesn't bother me that much, I quite like the old Vega tenor banjo neck it's quite narrow , and I can get away with mandolin fingering, the Buchanan is the same scale length but wider and I use more guitar style or a hybrid fingering and I enjoy playing that too.

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fox

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## fox

Yeah it might be OK but it looks a bit strange as I have tapered the V from the face of the fretboard to the underneath of the neck.
I have never even seen a V neck but I think my version might be a bit to radical.
I am also reluctant to glue the back on due to all the rain we have had and working in my outdoor shed, I think I need to bring all the components inside the house for a week or so.

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## derbex

It sounds like one of the bowl back mandolins I have, and I have played an F5 with a neck like that too. For me the main issue with a V neck is when you want to move the thumb around the back of the neck to play chords -especially barres, it's not very comfortable. My Matsakis bowl back OM has more of a deep U section (still no truss rod) which works reasonably well, and my banjo is probably more of a rounded V.

I'm no wood worker, but it sounds like a good idea to bring the bits inside to stabilise for a while, it's been very humid here the last few days.

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## colorado_al

Updates? Looks super cool!

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## fox

Thanks al, unfortunately we have had a very wet spell and my shed has become very humid, damp even!
I don't like to work in those conditions, the multi piece back would be very susceptible to moister at this stage due to all the different grains absorbing moister at different levels and possibly swelling up causing the joins to become uneven.
I have brought the components inside the house for now.
I can't make my mind up about the fretboard, Roswood or Ebony are standard but a little ordinary, I would prefer to use a figured piece of mahogany, I am wondering if I can heat up a piece to open the pours and then paint it with warm epoxy so I get maximum penetration and a long lasting hard finish... 
I also wonder about coating the inside of the back with carbon fibre weave, that would completely stabilise the wood but might effect the tone in a negative way... impossible to know without experimenting!
The last six string guitar I built had a fibreglass body, just a spruce top, it sounded really good and very loud but perhaps a bit sharp or crisp for my mellow taste.

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## derbex

Hi Fox, Are you intending this one to by nylon or steel strung?

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## fox

Both! I have a plan using one of my bridge designs that should allow efficient use of both string tensions.
I will use a zero nut, so string gauge wont be an issue, the steel strings will go over and under a bridge & be anchored at a tail piece. Nylon strings will fix directly to the bridge.
There is actually not so much difference in string tension as some folk might think, around 78lb for steel & 58 for nylon.

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## derbex

Very cunning.

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## fox

Black Adder!

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derbex

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## fox

I found time to apply a single layer of carbon fibre to the inside of the back.
I love the fingerboard wood.....



Sorry I can only get one pic to show..

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derbex

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## fox

Almost ready to fix the back on, just a top coat of epoxy on the underside of the back & a bit of cleaning up.
I am sticking to the rigid bridge loose edge design as this has worked very well for me in the past but I am always nervous at this stage as once the back is on it will be very differcult to adjust or add anything to the bracing..

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## derbex

Fascinating! (Star Trek quote, this time)

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fox

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## fox

The needs of the many outweigh the needs of the few..... I think he was a musician?

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derbex

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## OneChordTrick

> The needs of the many outweigh the needs of the few..... I think he was a musician?


You may be right  :Smile:

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fox, 

James Miller

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## fox

So I fitted a light set of GDAE strings and tried her out for the first time, a bit of titavation required but sounding ok!
Next up .. take off the strings and pegs, give it a good scrub and a few coats of oil.....

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40bpm, 

colorado_al, 

Cornfield, 

Jerusalem Ridge

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## fox

I need to test a few string sets & fine tune a few things, I find it a bit brash & hollow at the moment, a bit banjo sounding but with very long sustain. 
Certainly different to anything else I own.
The bridge is also acting as a structural member to hold a curved shape too the top, the under soundboard bracing is very light.
The tail piece is fixed to an adjustable height steel pin that goes down into the carbon 'square tube' that runs right up the neck.
This means I can adjust the pressure over the bridge & experiment with the effect.
The most interesting thing is that the whole instrument is resident & you can feel  vibrations all the way up the neck.
Not as loud as I would of liked, I have not tried it plugged in as yet, similar volume to a Bueridge .
It might take a few weeks to work out what works best & then my friend Jonny can have another go to see if we can improve the sound.

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## derbex

That looks stunning. On my computer it sounded guitar like when strummed, but did have a bit of banjo or resonator twang when picked -which gave it a some character. Good effort  :Smile:

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fox

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## fox

Thank you Jeremy, I appreciate your support.
I tried out many configurations & decided it was far more suited to CGDA. I thought a light set of 09 13 20 30 sounded best, for my ears anyway. 
So now I need to get it nice and shiny, I had already sealed it with some clear lacquer from a spray can, just a very light single coat.
I will use truoil on this one.
I also plan a few accessories, arm rest & pick guard.

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colorado_al

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## fox

Well I just couldnt cope with the look of the structural bridge and I thought the overall sound could be improved on so... 
off came the top and a new arch top caved and crossed braced.

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## derbex

I wasn't a huge fan of the bridge when I first saw it, but it's grown on me -looks like my face fungus  :Smile:

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## fox

Well new top now fitted...

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colorado_al

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## OneChordTrick

That looks better, to my eyes anyway. This is a fascinating thread, thanks for sharing

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fox

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## fox

Thanks, the new arch top seems to add more volume but less sustain, overall I feel it is an improvement.
I discovered a few things along the way too.
 Truoil is very time consuming to apply & takes an age to get hard & you cant spray anything over it! (well at least not acrylic lacquer) 
I really did not feel like starting over with the oil on the new top as it would take weeks to get it to match the rest of the body. So I sprayed the top with a lacquer however, even the tiny amount of overspray that seeped past the masking tape, reacted badly with the truiol!
Not easy this guitar building lark....

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## sonic

I have found from gun stock finishing (then used on my EOM neck). That truoil needs to be applied by hand not brush built up in very thin layers. The heat from your hands helps it harden. To rub down after a few coats use linseed oil with wet and dry as opposed to water. It doesn’t pick up and spoil the finish as I have found with water. Unless the truoil was very hard before rubbing down. I learned the technique from a gentleman who finishes shotgun stocks to a deep lustre with good depth to the shine too. I have had good results but am still working to get the standard he does. There’s another trick I read about on a shooting forum about hardening Truoil off quicker by spraying or adding something else. Can’t remember what but a search on gun stock refinishing might supply the answer. It truly is a lovely piece of work and I hope you have achieved the sound you are after. It has been very interesting following this build.

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fox

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## fox

Thanks Sonic, nice tip about the linseed oil.
Truoil is quite time consuming but does offer a partially nice finish when you get it right but, can be very frustrating getting there.
I also build gun stocks (air guns mainly) but I really specialise in spearguns. I use two pack polyurethane for those, I have often thought about using 2pac poly on my instruments but I fear it would be too thick & ridged a finish for the purpose.
However I have found nothing better than 2pac for giving that amazing shine & depth of finish!

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## fox

My friend James again, only an ipad vid but sounds ok with head phones.

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Drew Streip, 

Jill McAuley

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## CES

Really looks nice! Hard to judge the sound on my tinny work computer speaker, but will give a better listen when I get home. Agree this iteration sounds a little better than the first, even on the junky speaker. Thanks for posting, it's been fun to watch this project develop!

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fox

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## fox

Thanks Chuck, I don't own a decent camera ( that father Christmas he no listen) I found it interesting to hear it being played in front of me. Certainly a punchy & loud tenor.

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## fox

A bit more poor quality video....

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## derbex

It is interesting to hear an instrument played at you -I have a mandolin that I don't really like the sound of when I play it, but when it was played to me it was quite impressive.

Also interesting to hear how different the two guitars are, the one with the striped headstock has more of a guitar 'character', wheras the one in this thread has seems to have something of a banjo/resonator twang to it. Both sound good.

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fox

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## soliver

Looks and sounds good

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fox

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## fox

> I
> Also interesting to hear how different the two guitars are, the one with the striped headstock has more of a guitar 'character', wheras the one in this thread has seems to have something of a banjo/resonator twang to it. Both sound good.


Both are strung with the same strings - 12 18w 30w 45w but the flat top scale is 21" & the arch top is 23"
The flat top has wider spacing at the bridge (both have 32mm nuts) I feel the flat top has slightly more sustain but slightly less volume.
I think the more mellow flat top lends itself towards more gentle playing, fingerpicking, strumming &  chord melody. Whereas I think the archtop is more a session guitar.
Anyway the archtop will be shipped out to a new owner mid January, I will be sad to see it go....

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