First Classical Build

[ozziebluesman]

Hi to you all,

Its been a long time since I posted so I thought I would pick the brains of the good people here on classical guitar building. Steel string guitars have been on my bench for the past 15 years and I thought it about time to have a go at a classical. My health has been not so good for some years but the last twelve months has been good since the pacemaker was fitted. So I have not been slacking off but doing research about the classical guitar building during the rest time. I'm at the stage that over the past six months I have made all the parts to build three classical guitars. The first will have a bolt on neck as I know how to go about the neck geometry and the other two will be traditional builds on a solera. My mould is duel purpose and can be used for a body only build or with neck attached to the top built on a solera. The guitars have different spruce top species 2x Englemann (one for Graham Hein), 1x Lutz with Sapele, Blackwood and Silver Wattle backs and sides. The tops are thicknessed down to about 2.7 mm and the rosette's are fitted. The bolt on guitar has the rims ready in the mould for the top and back to be glued on. So now for the bit I have had no experience with, bracing the top and back.

I have chosen a very simple brace pattern first for the bolt on with the seven struts and two tail braces, soundhole patch with two transverse braces one glued flat and the other in the 28' foot radius dish. I am using the Neal Osberg plan 7/8th guitar shape of a FE18 Torres copy as a guide. I am not going to arch the second transverse brace on this build just to keep it simple. My intension is to do that on one of the the solera built guitars. I think I want to use a truss rod as well and would be happy to hear some discussion on that subject.

So what have you all been building into your classical builds that you feel is a good bracing combination? I am skeptical regard using carbon fiber but lots have with great success even with a torres seven strut systems.

Thanks for your attention and hope to hear soon your thoughts.

Cheers

Alan

[Steve.Toscano]

HI Alan, I'll break up my reply based on your questions

The tops are thicknessed down to about 2.7 mm and the rosette's are fitted.

Firstly, 2.7mm is quite a thick soundboard for a 7 fan classical. For good quality stiff engelmann I typically end up around 2.3 - 2.2 in the middle down to 1.9 - 2.0 at the edges. In saying that my braces start off slightly taller then most traditional designs.

I have chosen a very simple brace pattern first for the bolt on with the seven struts and two tail braces, soundhole patch with two transverse braces one glued flat and the other in the 28' foot radius dish.

While what you have described is fine, you'll find most traditional makers keep both top transverse braces flat (me included). My solera's are only domed in the middle area of the lower bout and is flat everywhere else, including the entire upper bout.

I am using the Neal Osberg plan 7/8th guitar shape of a FE18 Torres copy as a guide. I am not going to arch the second transverse brace on this build just to keep it simple. My intension is to do that on one of the the solera built guitars.

So this is a relatively small bodied instrument, in that case i'd seriously consider reducing the thickness of the soundboard. Assuming your soundboard doesn't resemble wet cardboard.

I think I want to use a truss rod as well and would be happy to hear some discussion on that subject.

Certainly fine on classical. about 80% of my classicals now have a dual action truss rod with access through the soundhole. The only downside here is the weight, try to pick a lighter weight neck material to compensate.

So what have you all been building into your classical builds that you feel is a good bracing combination? I am skeptical regard using carbon fiber but lots have with great success even with a torres seven strut systems.

My design is an asymmetrical 7 fan with a single slanted lower transverse. I modified this from a Hauser design. I have on numerous occasions done CF on the top only of the fans on this design, and it works well. Adds a lot of stiffness to the overall structure with approx half the brace size. So don't be scared to use CF.
One of the faults i see new comers to the classical realm do with fan bracing is to butt the fans up against the closing or lower transverse brace/s. In my opinion this is a bad idea.

Something else to think about is what you will do for soundboard edge kerfing/linning? Refer to Trevor's work on this topic.

[ozziebluesman]

Hi Steve,
Thank you very much for your reply.
You have shed light on a few things I was unsure of.
The tops are still nice and stiff and weigh 150 gram with the rosette in and soundhole cut out.
I will avoid gluing the struts against the transverse brace thanks for that tip.
In Neals plan he has 9 mm x 19 mm transverse braces. Is they a bit chunky?
Thank you again for your comments.
Cheers
Alan

[Steve.Toscano]

Hi Steve,
Thank you very much for your reply.
You have shed light on a few things I was unsure of.
The tops are still nice and stiff and weigh 150 gram with the rosette in and soundhole cut out.
I will avoid gluing the struts against the transverse brace thanks for that tip.
In Neals plan he has 9 mm x 19 mm transverse braces. Is they a bit chunky?
Thank you again for your comments.
Cheers
Alan

150grams doesnt sound too bad, I aim for my tops to be well under 140grams when at the same stage yours are at (under 170grams braced). However my plantila is 352mm across the lower bout so naturally should be heavier as its much larger then yours. Is the FE18 325mm lower bout?
That is quite large transverse braces. You could take a few mm off each dimension IMHO.

[ozziebluesman]

Hi Steve,
The tops are 355 mm at the LB 270 UB 230 W.
My mistake just checked it is the La Suprema FE19 plan by Neil Ostberg.
I thought maybe 8 mm x 16 mm for the second transverse and leave the first one a 9 mm x 19 mm.
I intend to extend the neck right to the soundhole to fully support the fingerboard.
Just trying to settle on my brace pla. Your input is very valuable to me.
Cheers
Alan

[ozziebluesman]

Also the Sapele back is 250 gram, a Blackwood also 250 gram and a Silver Wattle 190 gram.
After some research I found that a three ladder torres brace design for the back should be about B1 at the neck end 7 mm x 20 mm, B2 8 mm x 20 mm and B3 9 mm x 20 mm. Do you think they are reasonable sizes to start out at? They can be reduced easily.
I started making my own linings about four steel string guitars ago and make spruce reverse linings 15 mm x 6 mm and leave the kerf not so deep and bend the linings on the iron. That really stiffened up the sides on my builds. I would be interested in your comments when you have some spare time.
Cheers
Alan

[Dave M]

I have been building roughly to the GAL SE 114 plan and going to have a look I see they taper the back bars:
Head end 6.6 to 5.2
next 8.2 to 5.6
next 9.9 to 5.2

All at 18 high.

I couldn't persuade myself that these shapes were important so went for 10 by 20 high, rounded over at the top, and scalloped down to 2 for 50 mm at the ends. The back on that one was around 2.5, spherically braced at 5 m in figured maple. It came out very well - certainly my best so far.

Oh and the top in Engelman was around 2.1 to 2.2.

Cheers Dave M

[ozziebluesman]

Hi Dave,
More good experienced information to take in. Thank you.
I have ordered the GAL SE 114 plan but it has been 6 weeks and no sign of it yet. Being economy post from the US it may take some more time to get here. I believe it is very similar in size to the La Suprema FE 19. I am not looking to build a torres replica just the best sounding instrument I can. With no experience I need to ask a few questions before having a go.
Thanks again for your comments and your building specs.
Cheers
Alan

[Steve.Toscano]

I thought maybe 8 mm x 16 mm for the second transverse and leave the first one a 9 mm x 19 mm.

That will work fine. Dont be scared to shape these right up to a point.

After some research I found that a three ladder torres brace design for the back should be about B1 at the neck end 7 mm x 20 mm, B2 8 mm x 20 mm and B3 9 mm x 20 mm. Do you think they are reasonable sizes to start out at? They can be reduced easily.

Depending on what type of back you are trying to achieve eg live / non live, and back stiffness and thickness its hard to comment on the back braces sizes. But they are about close to what i'd expect on such an instrument, if anything they could be smaller, but as you say - easily reduced later.
My live back blackwood classicals have 3x ladder braces all at 8mm x 16mm. Back thickness typically in the range of 2.2 - 2.6mm depending on piece.

Also your reversed kerfing would be fine.

[ozziebluesman]

Hi Steve,
Thanks for your reply.
I am not using a live back on the sapele which has good stiffness, is 2.2 mm thick and it will be a bolt on neck.
The blackwood also a non live back and it is the same weight as the Sapele back at 2.2 mm thick and very stiff.
The Silver Wattle is stiff enough at 2.5 mm thick but is light weight and I would like to make this one with a live back.
Are the back braces also carved to a point or are they rounded?
Would you please have a close up pic of a top brace carved to a point?
I have the Gore book maybe even tell me wwhich page if there is a pic in there.
Thanks again for your help.
Cheers
Alan

[Dave M]

Alan there is a pic of a gabled brace in section 7 of G&G first edition - probably the same in the second. Fig 7-8.

I liked their jigs for routing the curved base and the gables. Makes the process much quicker.

[ozziebluesman]

Thanks Dave I will check it out.
Cheers
Al

[Steve.Toscano]

Apologies Alan, missed your response. I don't have a close up handy, but you can just see the carving with the soundboard pic at the bottom of this thread - viewtopic.php?f=25&t=8447

[ozziebluesman]

Thank you Steve very timely as I am into the top bracing right now.
Cheers
Alan

[ozziebluesman]

Hi everyone,
Just a few pics for you to see progress on the classical nylon string guitar. It is a FE19 shape but that's about all there is similar to an original Torres. It is a bolt on the same as I build a steel string, 7 strutt basic bracing slightly rounded and the transverse braces on the top and back are gable shape. I voiced it as I would normally do a steel string and the box is closed now and it taps nicely. The top is Engelmann, back and sides Sapele and Queensland Maple, Blackwood laminated neck. It has been an interesting exersize. At the same time I have prepared all the parts for two traditional Spanish Heel classical guitars. I intend to brace one with a torres 7 strutt using the SE114 plan and the other will be Radial bracing with an active back. More on those later. Some pics for you and thanks for your interest. Cheers Alan

[56nortondomy]

Coming along nicely Alan, looks very neat and clean be interested to see it finished.
Wayne

[ozziebluesman]

Hi Wayne,
Thanks mate I like to keep my builds tidy.
I was suprised at the tap response.
This one is for my long time student.
The next builds I will follow plans just to see what the difference is in tone.
I seem to think that a bolt on neck seems to be a much better build method than the Spanish Heel although they both have plus and negative vibes.
Thanks for your interest mate.
Send me some pics of your latest when you get a change.
Cheers
Al

[Dave M]

Alan that is indeed looking good. If you have (finally) received the Jeff Elliot plans for FE 114 you may be as surprised as I was at how small the fan bracing is. You have the wider bracing I notice that Torres seemed to use earlier. I was quite worried that the thing would give up on me when I got the strings to tension but both I have built seem fine.

I always use a bolt on neck a la Gore for everything as it just seems sensible. Since I don't have to sell my instruments I also do a cutaway on classicals. It again seems completely sensible.

I like to mix it up so I am back to a steel string as I don't think I've got them quite right yet. Using G&G's design.

[ozziebluesman]

Hi Dave and thank you for your comments.
Your steel string top design looks great and your work is very fine. I haven't ventured into carbon fiber yet but will in the near future.
I have received the Jeff Elliot plan and have studied it carefully. I noticed first the top thickness and then as you say how small the fan bracing is. It is however a great resource. My bracing is my take on the Neil Osberg plan freely available on the internet and it is a little bigger than the FE17. When I braced the top the two transverse braces where big in my opinion but they may need to be because the top specs are very thin. Because this is my first go I thought I would approach it as a steel string build and voice it the same way. I had to take a lot of material off the transverse braces to get a good tap. The top is also 2.5 mm thick approx and no where near the thickness of most other builders are going to including Jeff Elliot. Or are they? Seems like you can come at it with a thicker top and lighter thinner bracing or the opposit a very thin top with heavy bracing. Because I was not sure what to do I went with how I usually build a steel string and I am happy with the tap. I also will sand down the top around the edge of the lower bout once the instrument is built.
I would be very interested in your thoughts when you have time and any one else who has experienced building classical's and their thoughts.
Thank you Dave again.
Cheers
Alan