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If I want to build a 12 string guitar or an acoustic bass, is there anything I need to watch out for?

Also I was curious about making a harp guitar, I've never seen one before (such a thing does not exist in Taiwan) but does it have a regular guitar tuner on the arm?

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

I've used short scales on the 12-string guitars I have built. The top is a bit thicker around the bridge and in front to around the sound hole. Also bracing was slightly beefed up. So far they have been fine except for one which needed a neck reset after about ten years. But that was also one of my earlier guitars. If I was building one today I'd put in two carbon bars along with the adjustable truss rod too.

Depending on stringing and tuning a twelve string guitar may have about 50 percent more tension than an equivalent sixer. However many 12's are tuned down, have different scale lengths, and/or use different gauges of strings. The bottom of this has some very good starting information for calculating the tension on the top.

http://theunofficialmartinguitarforum.y ... ng-Tension

Once you have selected the scale length and know the tension you can determine how to compensate for it. I own a old Martin 12 string with short scale and standard 5/16 unscalloped bracing just like a D28 - it required a neck reset and developed bit of a belly after about 25 years. Taylor uses a thicker top plate and third tone bar - their standard 12's are not scalloped, but the LKSM which is designed to be down tuned 3 semi tones has thick braces that are fairly deeply scalloped. Guilds tend to have heavier braces and two truss rods (but still use a dovetail neck joint).

My OM sized twelve has 24.9 scale, is designed for D to D tuning with mediums (12's) and has a 0.120 top plate, 5/16 bracing with three tone bars and dovetail neck joint. It is a very responsive fingerstyle guitar that has held up well. I have also built a ladder braced long 26.5 scale copy of the old Stellas that is tuned C or C# and strung with heavy strings (13 or 14). It is a tailpiece guitar which means that the top in not under rotation - the ladder bracing and 0.125 thickness seem to be fine.



GAL has plans for a harp guitar and there have been several articles in American Lutherie.

Below are 12 strings threads I have bookmarked, I know some day I would like to make one for me, so I have been gathering information.
viewtopic.php?f=10101&t=30127
viewtopic.php?f=10101&t=30126
viewtopic.php?f=10101&t=29478
viewtopic.php?f=10101&t=28982
viewtopic.php?f=10101&t=28909

Rob

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http://shastaguitar.com/
http://www.kalimbakit.com/
http://www.youtube.com/user/comfyfootgr ... ature=mhee
http://www.facebook.com/robert.renick.7

I was asking because my customer is going to bring me a 12 string Stella (I think) to work on, so that got me curious. I might want to build a 12 string sometime and want to know things to watch for. I don't even know the right question to ask.

As for the guy who shot my ukelele down, he hasn't been very helpful in the area of "cracks in the market". Basically when I asked about stuff like baritones, harp guitar/ukes, etc. (none of those exists in Taiwan by the way) he basically said no one wants them because people only wants whats popular in the US. I am not even sure he wants to help me because he most likely sees me as a threat to his business, because he obviously wants people to throw away broken instruments and buy new ones rather than repair it.

All I really got from talking to him is that the music scene in Taiwan sucks and that America is the land flowing with milk and honey when it comes to music, and that the grass is always greener in Western countries.

Also my Asperger's means that I can't really chase a million different avenue of getting connection, my mind simply cannot handle it. I have to focus on fixing or building guitars, because anymore and I will go crazy.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Tai,
There is a person out there who can and will help you, do whatever you can to get out, put yourself in the right spot at the right time. If the music store contact is going no where, move on. Helping with shows, give it some more thought, I don't like to be scattered either, so I never volunteer to host the open mic or organize events. Simply showing up and helping with chairs and tables, bring some basic tools just in case, you will make relevant connections. We create our own momentum, in a direction.
Wish you the best, you will make it happen.
Rob

_________________
http://shastaguitar.com/
http://www.kalimbakit.com/
http://www.youtube.com/user/comfyfootgr ... ature=mhee
http://www.facebook.com/robert.renick.7

Well, the guy who owns the Stellas that I am restoring is a features reporter for a local English newspaper. He helped a lot although I do make a lot of stupid mistakes that ended up rubbing him the wrong way but he seems cool with it (I apologize whenever I make mistakes like that). I don't mean work related mistake, mostly social related mistakes.

I'll see where it takes me.

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Tai, two quick comments. There are two classes of "Stellas" (with several variations). The orginal ones, built in the thirties, we long scale ladder braced instruments. We associate them with Huddie Ledbetter (Leadbelly), Blind Willie McTell, BBQ Bob, Stefan Grossman has one as does Paul Geremia. They have an almost cult following and fetch very high prices when they appear. If you one of those, treat it with respect.

The second are the Harmony-Stellas of the 50's (I think, I'm not very knowledgeable about them). They were cheap guitar, have lots of problems, really aren't worth all that much (but you do see them advertized as the "real" stella). If you have one of those, reset the neck, fix the other problems and move on.

My second point is that in building a 12 string you can either make something generic - more or less standard strings, tuned to concert - and assume 50 percent more top tension. Stiffen the top accordingly. The other option is to build it to the tuning, strings and playing style of yourself or your commission - now you have all the issues of scale length, body size and shape, intonation issues (12's are typically bad), neck, bridge - even how to fit it in a case. If you are doing this you need to seriously design your guitar.

Good luck

If you want more information than you can possibly digest about harp guitars, go to www.harpguitars.net. You'll get an eye full.

Yep. Harp guitar is one of the least strictly defined instruments All sorts of different tunings, number of strings, shape of body. No need to be bound by tradition. Design it however you like, for tone, playing comfort, and whatever you think looks good.

You can use whatever kind of tuners you want on the harp arm, as long as they get the job done. I'll probably go with open geared guitar tuners to keep the weight down whenever I get to building my first one. Or perhaps even the ultra-light (and expensive) Gotoh stealth tuners... although they do have a 44lb string tension limit to watch out for. I think some designs use alternating guitar and banjo tuners (planetary gear, where the key sticks out the back of the headstock instead of off to the side) to get them really close together without crowding the keys. Whatever you use, you may have to drill the string hole larger on the lowest ones if your design needs high gauge strings.

Harp guitars are quite rare even in America. I've never encountered one in person. I think it would be really cool for you to be the first Taiwanese harp guitar builder. Might be hard to find customers for them, but it would certainly stand out and maybe get more attention for your regular guitars too... that is, if it sounds good.

As for bracing, I don't think there's any way to communicate everything even if I knew, which I don't, because I haven't built one yet, although my harp ukulele should serve as some reference. Use an X brace and a big sturdy upper transverse brace, since those are proven to work very well. Lay out the others in a fairly even looking pattern of some sort, whatever feels right.

Calculate your total string tension before you start... you need that as a mental reference during the thinning of the plate and carving of the braces. Different people use different methods of deciding how thick to make the plate and how to carve the braces. I prefer the "all natural" style, using my eyes and ears and fingers to decide what's right, rather than measured deflection testing and such. I do use a homemade thickness caliper on the plate to check for thick/thin spots and as a ballpark figure, but flexing the plate with my fingers is the main way I decide when to stop. Same with bracing, although I use my eyes to judge evenness and relative stiffness of all the braces. Always pay close attention to the connection points between braces.

Tap tone of free plates doesn't seem to mean that much to me, but once I get the sides glued to the top, and especially once I can spool clamp the back on to get some air chamber and back interaction mixed in, tapping is the main way I decide where and how much to shave. I ended up taking quite a bit off at this stage on the harp uke. At first it sounded hard and solid, sort of a "pok" sound. After shaving, more of a hollow box "pom" sound.

And if you've never built a test mule guitar, I'd highly recommend it. Great way to calibrate your senses reasonably quickly and inexpensively. Whip up an ugly guitar out of whatever cheap wood, but give it a reasonably good soundboard. Then retop it a few times, recycling the same soundboard if possible. Try different plate thickness, different bracing patterns, different profiling of braces (can do some shaving through the soundhole), different bridge shapes and woods, whatever you want. Push the limits of light bracing, and see how the top deforms when you go too far.

I just got the 12 string "stella" from the customer.

He says its a 1930's ladder braced guitar, not branded Stella but he says it's made by Oscar Schmidt based on the fingerboard dot pattern. Has a spruce top (I do not know if it's red spruce or sitka... how do I tell?) but the runout on the spruce is kinda bad (based on the split at the lower bout). Dark dyed fingerboard, needs to be replaced because it split right down the middle and has shrunk badly. Back and side is mahogany, not sure what kind but I am assuming Honduran or Cuban. The neck is mahogany I believe but someone saved it down, because the neck is thinner than it's supposed to be and there are some tear outs that indicates that someone has worked the neck. The bridge has a large piece of bone inlaid into it (not a very good job) and a saddle placed over the top, and the string is attached to a tailpiece.

The spruce soundboard is in poor condition, wish I can retop but he liked the sound of old tops, so it's not an option. Several cracks, including a broken lower bout with another broken piece. The fingerboard has caved in somehow from the string tension, taking the side and portions of the top with it. The side is severely split, luckily no attempted repairs. Missing wood near the bottom.

I will start a new thread with pictures tomorrow. He believes it's made by Oscar Schmidt but there are no way to know, but either way it's worth about 4000 or so (whether its a Regal or Oscar Schmidt or Stella) in mint condition.

Anyways, the fingerboard needs to be replaced, it's badly split and I am not going to attempt to repair that... An adjustable truss rod will be installed because the neck has been thinned beyond its design, and carbon reinforcement rod will be needed.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

Tai, just a quick comment about something you said earlier in the thread: the guy who thinks ukuleles aren't popular in the US obviously hasn't been here in the last 5-10 years! Tons of young people, especially, are picking up the uke (just go to YouTube and search "ukulele cover" for proof); more and more popular songs on Top 40 radio feature the uke as quirky, added flavor; and as a result, both mom 'n' pop music shops and mass-market retail stores like Guitar Center have dedicated floor space showcasing ukes. Here in Southern California, I often see teens and college kids carrying around uke cases, there's a ukulele festival every summer, and near me in Huntington Beach (aka "Surf City, USA") there's even a store that sells and repairs only ukuleles and manages to stay in business. So don't let that person's negativity hamper your building aspirations; he might not be as well-informed as he thinks he is.

Of course, I'm biased (see my avatar photo).

Just had to rant for a minute. You may now return to your discussion on 12-strings and other high wire acts.

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Dan Greene
Greene Guitars & Custom Strings
(currently just a pipe dream)

I don't recall him saying that ukes are unpopular... unless I made an incorrect statement at one point...

He only made it sound like America is the land flowing with milk and honey when it comes to music, and how limited the market is in Taiwan. He said he didn't like the sound of my challenge uke based on the fact that cheap Chinese ukes sounded louder. I can't say I like the way it felt either because I followed the plan far too well, and haven't really gotten the whole art part down yet. But I will say he seems to be doing fairly well considering that he only sells ukeleles, so I am not sure why he says what he says.

It could be the traditional mindset that America is always better than Taiwan.

_________________
Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com