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So I have built some greek instruments called bouzouki..they have no truss rod and they are similar to backbowl mandolin. I asjed peopld who build these instruments and they dont use a truss rod (most of them anyway) they place bigger tang frets so as to backbow the neck and then it supposed to come back with the string tension...my question is should I put sll the frets with a bigger tang or some of them?

I would put normal size tang frets in it to start with and then compression fret it with bigger sized tangs if it bows excessively. Wood deforms over time, so it would be hard to gauge how much back bow will be necessary to counter the pull of the strings.

Personally, If I were building it I would try to install a simple Gibson style truss rod that would be adjustable through the sound hole. Being able to adjust the action without changing frets might be a wonderful improvement.

Even classical guitar builders are putting truss rods on their guitars, and I have seen factory instruments with truss rods too, makes a heck of a difference in playability!

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I have repaired a number of guitars with no truss rods and the way I do it is install frets in every other slot and then take a measurement of the bow. If it still needs more backbow then I will crimp the tangs as I install the frets but I start filling them in from the center out. When I have achieved the proper back bow I stop crimping the tangs and finish fretting. Seems to work for me.

A truss rod will take care of the issue of having to put backbow in by either crimping the tang or using frets with thicker tangs. If you are building your instruments to exact spec's of the originals then I would follow tradition. If you are building a modern take on a vintage instrument then put a truss rod in and you won't have to mess with trying to get the bow correct.

Bob

thank you all for your answersRusRob csn you explain your method better?

pikolo.

Sure. In my situation with repairing a guitar with no truss rod, lets say the neck has too much relief (forward bow). What I would do is remove the frets and check the neck to see how flat it is with no frets. Lets say it has just a slight relief (forward bow). Since I know the neck has too much relief under string tension I want the neck to have a bit of back bow with the frets in. So I would clean the neck up and get it ready to start installing the frets. The frets I choose will have the proper tang for the slots and I will start installing the frets but skip every other one. So Frets 1, 3, 5, 7, 9, 12, 14,15, 16, 17, 18, to the end will have frets installed. The reason I install all the frets from 14 on up is because they are over the body and you don't need relief there.

At that point I check the neck to see how flat it is. If at that point if it still has some forward bow then I will use my crimper to crimp the tangs on a couple of the frets and install them in the center of the neck at #6 and #8. I check to see what difference that made (normally I will see the neck start to flatten out). Then I crimp the next 2 frets and install them at #4 and #9 and check the neck again. By this time I should start to see some back bow in the neck. Depending how much or little back bow I see I will either crimp the next set or just install them. In some cases I have had to remove a couple of the first frets I installed (Frets #5, #7 or #9) and crimp those frets as well to get the back bow that I want.

You can make a crimper or you can buy one but what it does is put little zig-zags in the tang which will make it fit tighter in the slot which will want to bend the fretboard backwards.
Here is a link to the Stew Mac one
http://www.stewmac.com/Luthier_Tools/Types_of_Tools/Pliers_and_Cutters/Fret_Crimper.html

I have both the Stew Mac on and one that I made myself which is not as aggressive.

Of course you can also buy fret wire with a thicker tang and do the same thing as above but not have to crimp them.

This process does take some experience to know how much the wider tang will back bow the neck and how many frets need to be crimped to achieve the proper back bow.

In the end you want to get the proper back bow and now days it is much easier to just install an adjustable truss rod so you don't have any of the guess work involved. But if you are building traditional instruments and you want to make them authentic with no truss rod then that is how you would do it.

Hope that helps.

Cheers,
Bob

I have another question for you, Bob... how do you get the oversize frets into the slots? I have a heck of a time hammering frets until I've ground the barbs almost completely off. Then it only takes a few fairly gentle taps, and with glue, they seem to stay put just fine. But certainly no backbow. I do bind all my fingerboards though, which prevents the slots from flexing open. Does that make compression fretting impossible?

Thanks Rusrob I have a Yamaha Classic I've owned since I bought it new in 1982. The neck has bowed I'll remove the frets and give that a try. I had stopped playing it anyway.


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Something I forgot to add in this equation is after you have installed the frets with the proper back bow you will need to level and dress the frets so you need to remember that the back bow you just put in can be completely un-done by leveling the frets so I usually either clamp the neck or be very careful when I file the frets that I don't remove the back bow. In a case like this I usually will just use my 6" beam with sandpaper on it to just barely take the tops off of the frets and check it frequently with a straight edge. This way you can be sure when the strings go back on you will have the correct relief. I have found that I may need to give some extra attention to a spot here and there after it is strung up but it is a pretty simple thing to do after the fact.

That is one of the reasons a truss rod is a great thing to have since you can actually put a bit of bow in a neck and then level it and dress the frets and adjust the truss rod after the fact to get the relief you want.

Cheers,
Bob

To be honest I have never had to do compression fretting on a bound fretboard but I am going to make a guess and say yes you can still do it since the binding will flex along with the board. I am also going to guess that you will probably have to crimp more than half of the frets (or use larger tanged frets).



After you have removed all the frets and cleaned the fretboard up you can use a small triangle file to bevel the edges of the fret slots. This will do 2 things, It will help keep chipping down if you have to remove them and will help guide the tang into the slots. I also apply lemon oil on the board after it is all cleaned up and ready to install the frets (I do both of these on every fret job I do). This will slightly soften up the wood in the slots and act as a lubricant so they go in easier. When putting in oversized frets or ones that have been crimped you want to coax them in and not try to hammer them in with one blow. I usually start on the side away from me and get the edge of the tang to set almost all the way down but not completely. At this point the fret is sitting about at a 5 or 10 degree angle. Then I will hold the close end of the fret with my fingers and lightly tap the fret in by walking my hammer down the fret. It should just ease into the slot. When i have the tang in the slot then I walk it back down the same way making sure it is seated all the way in. I personally never glue frets in unless there is no other choice. I prefer to have them fit correctly and let the barbs on the tang do the job they are meant to.

I guess the best advice I can give that I have learned is not to try to beat the frets in with one or 2 blows. Take it easy with quick little raps of the hammer and they will usually go in pretty smoothly.

Bob


If anyone has done compression fretting on a bound fretboard and can add facts to my "guesswork" then please do...

Thanks again for your answers! !!!! I would place a truss rod but it adds to much of weight to the
neck that the player never want.also a baglama or a tzoura instrument both have very thin necks that a truss rod would be impossible to fit in place,also you say "That is one of the reasons a truss rod is a great thing to have since you can actually put a bit of bow in a neck and then level it and dress the frets and adjust the truss rod after the fact to get the relief you want." you mean a back bow or a relief made to simulate the strings under tension and then leveling?

You might consider just putting a reinforcing rod of carbon fiber or metal in your neck to stiffen it up so it is less likely to bow. Most of the guitars that I have fixed without truss rods were either really inexpensive guitars or like some of the early 1970's Martins with just a square tube for reinforcement. You could also laminate your neck with a strip of stiffer wood in the center. Other people here have much more knowledge of that than I do so maybe someone can speak about that process.



Actually what I am talking about is with a truss rod you can adjust it before and after leveling the frets to suite the neck you are working on. Because there is such a wide variety of necks and how they move you have the ability to level the frets to suite the guitar. It is a little bit like simulating the string tension but it is not really the same. When you simulate the string tension you are bending the whole neck as if it had strings on it and then doing all of your work. When you release the clamps (or jig) and put the strings on you will have exactly the same tension on the neck as when you did the work on it. The truss rod adjustment only bows the neck from about the 3rd fret to the 12th or 14th fret with is where the "relief" is set.

I can see where you could think they are the same but it is really very different. Both deal with the flex of the neck but that is about all that is the same.

Bob

The Gibson style truss rods are only 3/16ths in. (4.7mm) thick and don't weigh very much compared to double acting rods. Greek bouzoukis don't have wide necks, but do have fairly deep necks. It should be possible to fit a simple rod, much as is done for a banjo. I buy mild steel rod from the hardware store and thread the end with a 10-32 die. Quick and cheap to make and install.

https://www.youtube.com/watch?v=iuPwc8x ... 63DFBFBFF2
I gave a talk on compression fretting a while ago at the ASIA symposium. Here is the link for it. The only difference would be how much back bow. I would shoot for about .005.
then with the frets in , to level then you can add about 5 to 7 lb on the body to flex the neck to simulate a string load. Then level them with the weight. The string tension should pull you in to the .004 to .006 range. If you are using guitar frets I do have the wider tang fret wire to help out
good luck and let us know how you make out

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well I lke the idea of a truss rod I am thinking why they dont make them from carbon fiber rods? imagine a two way adjustable truss rod very light and also stif enough(?) as for the problem I managed to solve it by compensating the f
nut by removing 1.20 mm or 0.5"(I think I made this is thw number in inches) of the front part of the fretboard (also if someone knows how to exactly compensate the nut and the bridge I would be happy to know...in detail or photos or even video...) so the string tension increased and know it plays very good with 1.9 mm syring action at the 12 fret.i will make it lower in a month or so maybe bring it to 1.7....now I am trying to make every note in tone...is that even possible? I searched in the web for information in compensation and I have seen these steps first you intonate the 2 and 14 fret to each other and with the bridge (I think it means if the 2 fret is sharp by 3 cent s the 14 should be sharp by 3 cents also) and after thwt you compensate the nut to make the sharpness go away? I dound it to difficult to do so I would likw more information oor is thwrw a compwnsate calculator? Some time ago I was fret slottinhg with a printed template of fret find 2d and I show that the nut position were 1.5 mm closer to firat frwt maybe fretfind 2d does a compensation by its own? tell me what you think

pikolo,

I know nothing about repairing a bouzouki but I do know guitars (or at least the repair of guitars). Since I have only just built one guitar I am probably not be best person to talk about getting the intonation correct other than placing the saddle or bridge on a guitar.

But I will have a go at explaining what I do know...

If you are having intonation problems at different locations on the frets then my guess is you do not have the frets spaced correctly. I don't know if a bouzouki has the same spacing as a guitar but you should check to make sure they are correct. Even a slight difference in measurements will have a drastic effect on intonation.

If you are using a standard guitar scale you might try one of the on line calculators:

http://www.ekips.org/tools/guitar/fretfind2d/

Or this:

http://www.stewmac.com/FretCalculator/


As for the intonation on a guitar that is normally done with a compensated saddle and then making small adjustments to the saddle by checking the intonation at the 12 fret. That is providing the fret spacing is correct. I have run into some inexpensive guitars where the frets are off and no amount of compensation will fix that problem, only removing the frets, filling the slots and starting over can fix a problem like that.

As for your instrument I am not really sure.

I know this probably doesn't help you a lot so maybe someone else that has more knowledge of a bouzouki could help more.

Bob

do you cut the face of the fretboard as I stated before?I read that this is how they compensate the nut