Top sinking on new ukuleles

Christian Schlichting

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Hi everybody! My name is Christian. I am like most of you an ukulele addicted suffering from UAS as many of you. Been playing since ten years and rarely touched my guitars since I started playing ukulele. Can't tell, what it is. It's just so much more versatile. They are everywhere. Where ever I am, I just have to reach out with my arm and have one in my hands. Believe me, I have been reading here since a long time, but as I am not a typical forum writer, I just read, never signed in. But this is such a wonderful community and now, when I see a first reason for posting a question to you much more experienced players, owners and builders, I feel ashamed, that it`s something about worries. I also posted this in the Four String Farmhouse on the UMGF, in case some of you see it there, too..

My concern is a sinking top and a strange brigde.
Two of my new aquisitions show the sinking top under string tension, one is a soprano, one a concert size. The soprano has the strange bridge. The other one's bridge is straight.

Both are Sigma Ukuleles, all solid hog, kerfed linings, light bracings, build well and sounding very nice.

The soprano is shown here. It weighs 340 g, the top thickness measured in the soundhole is about 1,8 mm. The bridge looks rotated, but upon closer inspection, it is bomb fast. No gap, just missing finish, where it looks opened on the fotos. In a magnified foto it looks as it was shaped trapezoid, when you get, what I mean. I put a straight ruler across the top to show you the amount of dipping. The dip is 1 mm lentghwise and 2 mm across at the lowest points.

I am not the typical complaining customer, who measures everything and suspects faulty workmanship. Also do I believe, that there is some natural physics involved, that a thin and light top warps under string tension. But how much is too much?

For better information: The soprano ist strung with a Worth Brown Low-G 0.358, the rest are Martin 600. Tuning is GCEA Low-G. Humidity is ok, as I live in an old farm house in Northwest Germany, 100 km from the coast. Not an arid area.

Hope, you can help me decide, what to do! Both sound really nice, action is perfect on both, just 2,4 mm about the 12th fret, no string buzz, playability is about perfect. Shall I live with it, or return? My laminate do also have a little sinking but it never worried me. But these are solid. Thanks!!
 

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This is common and as long as the intonation is not wrong nothing to worry about. If it gets worse then you want to take it to a luthier.
I have seen this on cheap and expensive ukes. Laminate tops should infact have less of this as the stiffness can be better controlled than finding a piece of wood that is stiff and thin.
In short, if stable and intonation is right, don’t worry.
 
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In pic 1980404 it looks like the bridge is just starting to lift towards the rear. It's likely the bridge was glued directly to the glossy finish rather than on the wood. Once it works off—if it does—I usually remove the glossy finish on the top and re-glue the bridge directly to the soundboard wood. Adheres much better and you might get a slight improvement in sound.
 
In pic 1980404 it looks like the bridge is just starting to lift towards the rear. It's likely the bridge was glued directly to the glossy finish rather than on the wood. Once it works off—if it does—I usually remove the glossy finish on the top and re-glue the bridge directly to the soundboard wood. Adheres much better and you might get a slight improvement in sound.

Thank you!

I can see through the gaps of the string slots, that there is no laquer where the bridge is glued. Around the rim of the bridge there is a very faint area without laquer or finish. So, the bridge is glued directly onto the wood, after the laquer was removed carefully. Inspected with magnification, there is no gap between the rear of the bridge and the top wood. Rock solid here..
 
After hearing your opinions on this and having received exactly the same at UMGF, no worries any longer.

Thanks all of you! Have a nice week, stay healthy everybody!

Cheers
Chris
 
Minor - and often typical. I have a concert that's been like that for more than a decade and it still doesn't affect its play-ability.
 
Sorry, but I have to disagree with this statement. The right support will not mute the sound. I don't know of any builder that built the top so it would dip, on purpose or not. Dips in the top are easily avoided with the top built with a slight radius or bracing designed to stop the dip. Ukes are a system were everything depends on everything else when it is constructed. Care must be taken to build things right. Mass produced instruments often suffer this dipping problem, as do instruments were the bracing has given up or was weak in the first place. Many older guitars suffered because of bracing failure. Once the bracing was replaced, everything comes back to life. Also remember, its the top plate that produces the sound, not the bracing.

Not my area of expertise, but I suspect there's conflict between making the top rigid and letting it vibrate. Lots of support would keep it from dipping, but it would also mute the sound.
 
Always great to hear from Duane, one of the great (now retired) builders.
 
Sorry, but I have to disagree with this statement. The right support will not mute the sound. I don't know of any builder that built the top so it would dip, on purpose or not. Dips in the top are easily avoided with the top built with a slight radius or bracing designed to stop the dip. Ukes are a system were everything depends on everything else when it is constructed. Care must be taken to build things right. Mass produced instruments often suffer this dipping problem, as do instruments were the bracing has given up or was weak in the first place. Many older guitars suffered because of bracing failure. Once the bracing was replaced, everything comes back to life. Also remember, its the top plate that produces the sound, not the bracing.

I do agree with much of what you say and as an owner of a Scott Wise ukulele which has been built with a slight radius in the top I know exactly what you mean.

Yet, if you are building an instrument and strictly using "flat top" construction methods, then a flat top that stays absolutely flat and doesn't dish at all one way or another is an overbuilt top in my experience.
 
I don't have any first hand experience with vintage Martins, Gibsons, Favillas or other factory made 20s, 30s, 40s or so Ukes, but I read, that they are mostly extremely light built, with tops as thin as about 1.5 mm (0.059). I wonder, if these instruments had dipping tops, too, or if this is a modern problem. Can you vintage Martin owners please check this and tell? Without it to cause panic, when you discover a dipping, hopefully! Do these vintage instruments dip, when they are confronted with higher tension strings such as some flourocarbons? Or had they sufficiently matured or aged to stand up to harder tension more as when new?

(Now I think loud, being glad, that no one listen:)

My thoughts are: Maybe the material used in these vintage specimen (Mahogany, Koa) was from significant better sources than today's. Maybe the Mahogany for example was much older, slowly seasoned over longer periods, denser and stiffer. Perhaps could they develope cracks during their first two or three decades, but they eventually dried out over time until a point was reached, where they weren't prone to cracking any longer, when not extreme changes of the conditions occured. Once repaired (cracks filled, wood patched), they are today possibly more stable than ever before.
Are today's wood sources used by mass producers inferior just for economic reasons whereas hand builders can use higher qualities? How can Kenn Timms and others build their ukes with 1,5 mm thin tops without fear of dipping or cracking? Or do they dip under string load? And no one minds because of the good volume and tone? Are kiln dried woods not suitable for thin tops? Maybe I should put my unstringed uke away until it has seasoned enough and string it up, when I am 80 years old to see, if the top still dips. Or put it in the kitchen oven in 50°C (122°F) for some days, let it crack, repair it and off I go.

What did a young man like Cliff Edwards feel, when the top of his first Martin Uke, which he just had bought with his hard earned money ("Ukulele Ike" once said to have chosen the Ukulele, because this was the cheapest instrument, the shop had, and the only he could afford), dipped under string tension? Did he take notice of it at all or was he just playing it without inspecting it hour for hour for changes and imperfections like we maybe do? Are we more picky today, used to things that are perfect from the start? Did the old bones nanny their instruments like we are always educated to do, using humidifiers in their cases and checking for perfect storing conditions?

I guess, many 20s Ukes were bought, played a short while until the flame of interest was extinguished, than put under the bed where they are found decades later, when the lady had died (just imagination) and put on auction? I guess most people during the golden age of ukuleles bought only one and were satisfied. Maybe we have too many ukes availlable over the internet, that we are pulled into the quest for the best bang for the buck and the ultimative sound, which we maybe never will find, and so we buy and buy, and sell and sell, just to buy another and another (talking about me). There is even a term for this behavior: UAS! Am I satisfied, when I have my 20s Style 0? Or would I discover a dipped top? Or maybe doubt, that I have a good sounding one? Maybe there are differences? Maybe the other Style 0 sounds fuller and louder? Or is a later build, say 50s better? Will there soon come another Style 0? And a Style 1? Or maybe better a Style 3, because James Hill sounds so good on his?

In other words: will we ever be satisfied with what we get or have? I mean, I buy one uke after the other over the years, searching for "the" sound! But what is "the" sound to me? Is my hearing shaped by listening to old recordings (I know that old Django Reinhard recordings have manifested in my brain so much, that I don't like listening to modern digital recordings of his stuff played by artists using modern Selmer replicas). Or is it shaped by youtube videos? I made the test: I listened to my playing and found my ukes sounding not like I wanted them to sound (years ago). Then I came to the idea to record myself with my phone and listen to it through my computer speakers, like I would with a youtube vid. I was happy with what I heard, it soundel like all the other ukes at youtube! (This is the reason, why I can't find any sense in youtube videos, where people compare the sound of different ukes to give people like me the opportunity to decide which one to like more).
Would I like the sound of "Singing In The Rain", when I would play it on Cliffs original uke? Or am I too much wanting the sound to be like I know it from his original recording in "Hollywood Revue" (by the way, I can't play like him of course, can't even make out, if he used Low-G C-tuning and just tuned down a half or full note!)?

Now my loud thinking is at it's end. Good, that you did not listen.


I decided to stop thinking about my dipped top. I will remove some of the uke's "satin finish" with 000 Steelwool and play the thing. I even decided to stop babying it with humidifiers and such. I live in Northern Germany, just 150 km (93 Miles) from the sea in an old farmhouse. When it cracks, than it cracks and I repair it (have done alot delicate woodworking in my life). I just wait and see, what happens. Don't know what I would do, if it was an old Martin. Maybe the same, as I can assume, that it has been through decades of neglect, just to end up humidified by me for the first time in it's existing, if I'd care.

End of the story: I am very satisfied with how this thing sounds! I will enjoy it without fearing anything. May it go long or not. May I say, that those were very good days, when I had my first cheap Mahalo uke! I was not thinking at all about other things than just playing it and having fun.

Thanks for your patience! It was just my lock-down's abundance of spare time speaking.
 
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I wish people would stop referring to slight distortion in the soundboard of a ukulele as a problem. It isn't. I have a sixty year old Martin style 1, and a ninety-two year old Gibson. Both are sopranos (of course) and both have the characteristic dip and bulge. All but one of my many ukes are sopranos and all of them dip slightly. There was thread on here a few years ago which covered the subject in great detail.

If the front distorts excessively, it can tilt the bridge very noticeably, and this will affect the intonation. Then you've got a problem.

John Colter
 
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I have a sixty year old Martin style 1, and a ninety-two year old Gibson. Both are sopranos (of course) and both have the characteristic dip and bulge. All but one of my many ukes are sopranos and all of them dip slightly.

Thank you! This is exactly what I was believing. I also am convinced, that it is natural physics, that a thin and flexible top must dip and bulge when excentric forces affect it. I believe, one can either have a thin and dipping top or a straight and sturdy but thicker top or at least heavier or stiffer braced when using the simple cross-bracing. Don't know what an effect fan bracing has. I am going to search for the old thread now.
 
OK. I have a fair bit of experience in this. Soundboards that are domed (as in most guitars) don't suffer from this problem, at least not when they are relatively new. String tension (over many years) does have it's effects and is why neck resets are sometimes necessary. Soundboards that are built flat tend to go concave soon after they have been built. They can do so even before they have seen any strings - due to fluctuations in humidity. They don't seem to recover either, even when the correct humidity is restored. The vast majority of 19 th century ladder braced guitars were built flat.
In short your Uke is probably fine. . . . unless the soundboard really is too weak and it's caving in due to string tension. If that is the case then you should see a severe dip in front of the bridge and a bulge behind it due to the rotational force on the bridge.
Just make sure that the bridge isn't coming loose on that back edge.
 
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