First Classical Build

Talk about musical instrument construction, setup and repair.

Moderators: kiwigeo, Jeremy D

Post Reply
User avatar
ozziebluesman
Blackwood
Posts: 1412
Joined: Wed Oct 10, 2007 9:12 am
Location: Townsville
Contact:

First Classical Build

Post by ozziebluesman » Mon Aug 19, 2019 12:03 pm

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
"Play to express, not to impress"

Alan Hamley

http://www.hamleyfineguitars.com/

User avatar
Steve.Toscano
Blackwood
Posts: 358
Joined: Thu Feb 07, 2013 11:43 pm
Location: Sydney

Re: First Classical Build

Post by Steve.Toscano » Mon Aug 19, 2019 6:38 pm

HI Alan, I'll break up my reply based on your questions
ozziebluesman wrote:
Mon Aug 19, 2019 12:03 pm
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.
ozziebluesman wrote:
Mon Aug 19, 2019 12:03 pm
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.
ozziebluesman wrote:
Mon Aug 19, 2019 12:03 pm
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.
ozziebluesman wrote:
Mon Aug 19, 2019 12:03 pm
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.
ozziebluesman wrote:
Mon Aug 19, 2019 12:03 pm
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. :)

User avatar
ozziebluesman
Blackwood
Posts: 1412
Joined: Wed Oct 10, 2007 9:12 am
Location: Townsville
Contact:

Re: First Classical Build

Post by ozziebluesman » Mon Aug 19, 2019 7:27 pm

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
"Play to express, not to impress"

Alan Hamley

http://www.hamleyfineguitars.com/

User avatar
Steve.Toscano
Blackwood
Posts: 358
Joined: Thu Feb 07, 2013 11:43 pm
Location: Sydney

Re: First Classical Build

Post by Steve.Toscano » Mon Aug 19, 2019 8:10 pm

ozziebluesman wrote:
Mon Aug 19, 2019 7:27 pm
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.

User avatar
ozziebluesman
Blackwood
Posts: 1412
Joined: Wed Oct 10, 2007 9:12 am
Location: Townsville
Contact:

Re: First Classical Build

Post by ozziebluesman » Mon Aug 19, 2019 8:40 pm

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
"Play to express, not to impress"

Alan Hamley

http://www.hamleyfineguitars.com/

User avatar
ozziebluesman
Blackwood
Posts: 1412
Joined: Wed Oct 10, 2007 9:12 am
Location: Townsville
Contact:

Re: First Classical Build

Post by ozziebluesman » Mon Aug 19, 2019 9:37 pm

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
"Play to express, not to impress"

Alan Hamley

http://www.hamleyfineguitars.com/

Dave M
Blackwood
Posts: 315
Joined: Tue Jul 15, 2014 6:44 am
Location: Somerset UK

Re: First Classical Build

Post by Dave M » Tue Aug 20, 2019 2:19 am

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
------------------
Dave

User avatar
ozziebluesman
Blackwood
Posts: 1412
Joined: Wed Oct 10, 2007 9:12 am
Location: Townsville
Contact:

Re: First Classical Build

Post by ozziebluesman » Tue Aug 20, 2019 9:21 am

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
"Play to express, not to impress"

Alan Hamley

http://www.hamleyfineguitars.com/

User avatar
Steve.Toscano
Blackwood
Posts: 358
Joined: Thu Feb 07, 2013 11:43 pm
Location: Sydney

Re: First Classical Build

Post by Steve.Toscano » Tue Aug 20, 2019 11:46 am

ozziebluesman wrote:
Mon Aug 19, 2019 8:40 pm
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.
ozziebluesman wrote:
Mon Aug 19, 2019 9:37 pm
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.

User avatar
ozziebluesman
Blackwood
Posts: 1412
Joined: Wed Oct 10, 2007 9:12 am
Location: Townsville
Contact:

Re: First Classical Build

Post by ozziebluesman » Tue Aug 20, 2019 12:18 pm

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
"Play to express, not to impress"

Alan Hamley

http://www.hamleyfineguitars.com/

Dave M
Blackwood
Posts: 315
Joined: Tue Jul 15, 2014 6:44 am
Location: Somerset UK

Re: First Classical Build

Post by Dave M » Wed Aug 21, 2019 3:09 am

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.
------------------
Dave

User avatar
ozziebluesman
Blackwood
Posts: 1412
Joined: Wed Oct 10, 2007 9:12 am
Location: Townsville
Contact:

Re: First Classical Build

Post by ozziebluesman » Wed Aug 21, 2019 2:53 pm

Thanks Dave I will check it out.
Cheers
Al
"Play to express, not to impress"

Alan Hamley

http://www.hamleyfineguitars.com/

User avatar
Steve.Toscano
Blackwood
Posts: 358
Joined: Thu Feb 07, 2013 11:43 pm
Location: Sydney

Re: First Classical Build

Post by Steve.Toscano » Thu Aug 29, 2019 7:11 pm

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

User avatar
ozziebluesman
Blackwood
Posts: 1412
Joined: Wed Oct 10, 2007 9:12 am
Location: Townsville
Contact:

Re: First Classical Build

Post by ozziebluesman » Sat Aug 31, 2019 10:45 am

Thank you Steve very timely as I am into the top bracing right now.
Cheers
Alan
"Play to express, not to impress"

Alan Hamley

http://www.hamleyfineguitars.com/

Post Reply

Who is online

Users browsing this forum: No registered users and 26 guests