Official Luthiers Forum!

Hello to everyone, i write from Italy and this is my first message in this wonderfull forum. I am a guitar player and a conductor and about 3 years ago the wonderfull idea to build a classical guitar came in my mind. And this finally i did: my first classical was finished after two years and half of reading forums (and this more than others), working, reading guitar building books, working, working hard to repair my mistakes i've done along this long yourney on my first buiding.
About two months ago i decided to build my second guitar, that means for me to build my really my FIRST guitar because my first was not so nice to see and not so powerfull and rich in the sound, but, i must say, wonderfull playable. I've finished till now the neck and the top and i decided to make a light top with laminated braces, yes, a five fan laminated braces. I've been reading on the book of J.S. Bogdanovich that for a cedar top he suggest to thickness the top to .090 on the edges and .100 above the bridge. So my idea was:" If i use laminated braces i can go a little more down in thickness" and with my stanley block plane began to thickness my top but... Unfortunately i was distracted by the paradisiac last movement of the Ninth Symphony of Mahler that i was listening during that work and made the unforgivable mistake to go too down. Take a look at the photos of my soundboard:



This is the first time that i upload an image on a forum, hope everything has gone well!

Where you see the dot in the soundboard, that is the center of the bridge location

So, this is the question, what can i do now to save my SB and all the work i have put on it?
I can only think at these possibilities:

1) Make a 7 or 9 fan braced soundboard with 3 pieces all wood laminated braces

2) Make an all wood lattice bracing like this, for example: http://www.byersguitars.com/Workshop/Workshop.html or these: http://www.redcliffguitars.co.uk/guitars.htm
http://coleguitars.com/

3) make the same lattice bracing but with thinnest laminated braces
4)Throw out my soundboard, of course, NO PLEASE...

I am very gratefull for the help you'd like to give to me
Regards,
Massimo.
P.S: Please, excuse my English. I hope you will understand what i have written.

Looks like you have gone way too far. You could only save it for a double top, although it is already very thin and it might get too distorted? Hopefully someone will double top experience will reply.

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Build log

Based upon what I've read in the past and the questions I've asked about a similar top, I agree a double top using nomex would be your best option. The top and bottom laminates are usually around .6mm or .024in, then you add the thickness of the nomex (which supposedly sands quite well also) and thickness the overall top to around 2.6mm or .100-.105in. in the middle and about 2mm or .080-.085 on the edges and leaving the upper bout at the 2.6mm range. Here are some pics from Tim McKnight on his double top construction and I'm sure someone here can point you to more info. Good luck and welcome to OLF!
http://www.mcknightguitars.com/soundboards.html

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Bobby Masten

Hello Maximus

Unfortunatly, my advice would be to start again with a new top .

Yes, this one top could be used for a double top or lattice style, but these are advanced techniques that should not be attempted by someone who has only built one guitar before.

You mention that your first guitar is "not so nice to see and not so powerfull and rich in the sound". That is all right for a first attempt. In my opinion, you should try to improve on that by using a plan of a well proven design (Hauser style, for example) and concentrate on reproducing it as closely as possible. Your chance of making a good guitar is then much better and you will more likely be pleased with the results. It is best to leave the innovations to the more experienced luthiers until you have at least become very comfortable with the basics of a well constructed guitar (you need to build a few good ones to get to that level).

I hope this helps, and don't be discouraged by this mistake on your top. It is a part of the learning process.

Cheers

Pat

I agree that that top should be set aside and try again with a new one. I can't imagine trying to do a double top without a drum sander, I'd think you would need the hands of a fine surgeon to block plane a DT to the proper thickness. But that top can certainly be set aside for a double top project. I'd also recommend getting a joiner plane to thickness the top.

I'd be nervous about using the jointer/planer for thicknessing anything close to spec as the potential for tearout is always present. For those that don't yet have a drum sander you could try what I did for my first 2 tops (before I ruined them in other ways) was to visit a local cabinet shop or two. They all have some type of drum sander and for a nominal fee are willing to thickness some wood for you. I think I took about 6 boards total including the 2 tops and paid the local shop around $20 for what took him 15 minutes of work. Was well worth it.

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Bobby Masten

It should work very well with a plane too. A good one, well sharpened, cuts effortlessly, and the shavings can go to as thin as 15 microns or so. I had to pile some 8 of these to make a 0.1mm measurement!

http://i299.photobucket.com/albums/mm30 ... ss/15b.jpg

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Build log

Scrap it Maximus and stop listening to Mahler! Bach is much more suitable, you will make less mistakes I promise you.

I mean a hand plane, a long one, aren't those called jointer planes?

Yes, you said it correctly. I understood what you meant.
L

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Cut to size.....Beat to fit.....Paint to match.

See what happens when you listen to a Bohemian? Pretty soon you can't live within a proper boundry.

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I read Emerson on the can. A foolish consistency is the hobgoblin of little minds...true...but a consistent reading of Emerson has its uses nevertheless.

StuMusic

By the way Massimo (aka Maximus), welcome to OLF!

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Bill Hodge


One does not simply, own enough guitars!

Thank you for the replies! I am, i must admit, very discouraged for the fact that i am in a position where throw out this soundboard seems the only thing to do now. But, even if i appreciate your suggestion to start with a new top, i'd like to try to brace this top with a lattice bracing; i mean an all wood lattice bracing, spruce probably. But not the thing you prepare before and only after glue to the top but maybe, i am just imaging now, a seven for seven braces where the first seven are notched to incorporate the other seven (i hope these are the correct words in you language to describe what i have in my minds). And yes, i can tell how much i find wise the suggestion to try to make a replicas of the famous patterns tried a million time before, that work well for sure, but, you know, why not try to play with this new challenge now: the all wood lattice bracing.
I am Italian, yes, i know

Massimo

OK, do the Byers lattice, but first of all, glue in a large bridge patch. I mean LARGE: 50-60mm wide, 26 cm long. Make it 1mm thick and then gradually thin it towards the edges so it ends up at the soundboard level. Make sure you do this in your solera or dish (hopefuly you have these) in max 45% humidity.

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Build log

+1
Do not Know enough to help...
can share my taste in music...
an anti landmine song...
great @100 watt suround...
http://www.youtube.com/watch?v=8JjQGt7WjK0

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"It's a Tone Faerie thing"
"Da goal is to sharpen ur wit as well as ye Sgian Dubh"
"Sippin Loch Dhu @Black lake" ,Kirby O...

Thank you for your reply alexandru, yes i have a 25 radiused dish (and a 15 for the back), i have a solera with the same radius i have putted in. But something i do not understand well: when i will apply the bridge patch you are talking about how do i glue the lattice braces? I have to escavate the channels on the patch to let the braces pass inside it? Am i right?

I'd recommend doing some additional stiffening in the upper bout too. Particularly around the sound hole. You are pretty thin there, and maybe a couple of finger braces in the wings of the waist. Above the sound hole, you might also put in a good stiff fingerboard patch under the area between the two upper TB's.

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Waddy

Photobucket Build Album Library

Sound Clips of most of my guitars

As a newbie, I would recommend setting this top aside until you have a bit more experience with the process.

When you are ready to revisit this top, you might consider a smaller instrument, such as a Jose Ramirez Senorita-sized nylon string, as featured on the back page of Acoustic Guitar magazine a few years ago.

Perhaps you can beef up the bridge area with a oversized, tapered bridge pad. For inspiration that is outside the box, look at the latest Kevin Ryan bridge plate.

No matter what you do, you'll learn something.

Usually luthiers excavate the braces (not that I agree with this). You can't really do that for the low fan, so you will have to make it from segments that stop at the patch. The notches in the tall fan will be pretty long...all the tangling would be a difficult project for a beginner. But...good luck!

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Build log

Lattice sounds good to me. Granted, I only have one guitar under my belt, and it's a steel string... but I read a lot.

I'd make the neck/headblock extend all the way to the upper cross strut so nothing is depending on the strength of that thin top to resist buckling. Also make sure you have nice strong braces along the sides of the soundhole connecting the cross struts together.

Alternatively, you could just laminate another layer of wood covering the area above the lower cross strut so only the lower bout is super thin.

I like the Byers lattice. The angle of the braces keeps the main stiffening in the direction of the string pull, similar to fan bracing instead of stiffening both directions equally like a lattice of squares.

Here is a very good technique for making lattice braces: http://www.luthiersforum.com/forum/viewtopic.php?f=10101&t=23892&p=325447&hilit=lattice#p325447

Not sure how to deal with the lattice going over or through the bridge patch... the dome of the top makes it much more complicated than it could be, just gluing the lattice together, using a router to cut a matching depth into the braces that pass over the patch, and then gluing it onto the top.

And one more thing. When working with lattices, one of the big variables is the stiffness at the perimeter of the top. Toward the center, the stiffness stays pretty constant, but as you approach the edges (the last inch or so), it naturally gets very stiff, so you need to shave down the braces to counter the effect or you won't get enough monopole movement (whole top pumping in and out). But too much and the monopole motion eats all the string energy and your guitar is too bass-heavy. I've never built a lattice, so I don't know what the sweet spot is, just that it's something to think about. Don't shave too much until you get the sides glued to the top, so you can tap on it and hear the effect of perimeter stiffness.

Thank you for all of your replies I have appreciated them very much. Just now i am fighting with making double sides and when i will finish this job i will begin to project and make braces for my top and i will follow your suggestion and, of course, will show to you my progress in this stage of construction of my second classical. Unfortunately all this week i will be VERY busy with my job and i don't think i will do much on lutherie.
Massimo

Hi, i wanna show you my progress in my first lattice bracing; first of all i needed to visualize something close to a lattice to better understand what i can do with it and i have used my binding material:


and after, with ruler and pencil, this is the best i could do:

Now i am occupied with my japanese saw to cut all the pieces for the lamination of these braces (spruce-spruce side by side) and after with block plane, double stick tape and scraper trimming to dimension all of them. Any advice regarding the dimensions of the braces?
Massimo

I would pull it a bit more close together. The outer four, short, braces, are too close to the edge. Just a feeling.

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Build log

Thank you for your reply, Alexandru, i will now riformulate the drawing leaving more space off the edges and putting more close the braces.
Massimo

Hi, here i am with my progress on bracing this soundboard. I've been pressed with my job and a little amount of time was left to me to work on lutherie, but, finally, i've finished to brace it.
I've done my...worst. to project and apply this lattice bracing and i must say that it was very very difficult and have taken a great amount of time to prepare the braces, gluing and notching the 9 tallest braces over the others. And some mistakes are obvious expecially with the notching:


Anyway, i will now try to laminate the linings and glue them on the sides.
More to follow, of course!
P.S: thank to all of you for the replies, and a special thank to JohnAbercrombie who have discussed with my problems of the lattice bracing.