Does anyone have any walnut off cuts? I screwed up big time!

[Michelle_K]

Ok so I am half way through building my first ukulele with very little woodworking experience or knowledge prior to starting.
It was going ok until I got to bending the sides. The side thickness should have been between 1.8 and 2mm. I thought I had thicknessed them to the correct size and began bending. Half way through I realised that one side was bending easier then the other. I checked the thickness again and it was 3mm! In an attempt to save the side I tried to unbend it which has made it worse as now they are all warped so I don't think I can salvage it or get it straight enough to plane and then rebend.

So I was hoping someone may have some walnut scraps that I could buy to use as new sides. The rough dimensions I need are 50cm long, 8cm wide and anything above 2mm thick. I know it's a long shot I have phoned around some luthier suppliers but none have any sides along I'd have to buy a while set which I don't need.

Thanks everyone

 

[Kalimna]

Cant really help with the walnut, but a possibility to straighten out your sides might be to give them a good spritzing with water and gently use the heat/flatness of an iron (the sort that shirts get ironed with ) on a flat and stable surface (e.g. plywood offcut or similar) to knock out the uneven bends.
Could you post up a photo of your sides?

Adam

 

[Zeddedhed]

I think I can help.

I've got a board that's about 160mm wide, 1165mm long and approx 5 - 7mm thick.

I'll put some pieces up in an hour or so and if you want it then it's all yours.

Since you're only in South London it's probably best if you collect it (I'm in Tunbridge Wells - about 40 mins from SE London)

Pete

 

[Zeddedhed]

Piccys as promised:

PM me if you're interested.

 

[NazNomad]

Steam it, it'll straighten out and re-bend with no (or very few) problems.

That thin, a boiling kettle would most likely work well enough.

 

[custard]

European Walnut or American Black Walnut?

I've got off cuts of both that would suit your dimensions. I'm tied up for the next ten days but if you're not sorted out by then then let me know and you're welcome to have some.

Good luck!

 

[profchris]

I think the grain on Zeddedhed's board might give you problems bending, unless it's vertical grain with some fairly wild figuring (if so, you'll need a metal backing strip, I use aluminium salvaged from a caravan).

If no-one here can help you, Rob Collins at tinguitar.com will be able to thickness some for you (if he has walnut in stock), and won't be too expensive.

 

[Michelle_K]

Thank you everyone for the advice and kind offers of help. Here is a picture of the walnut. I'm not even sure what kind it is. As you can see the glue is a mess. Not having a go bar deck or many clamps the braces didn't make contact across the wood so had to top up the glue which caused chaos. I really want to build myself some can clamps but that's a project for the future. I don't have access to power tools and making multiple clamps by hand is a bit daunting. But I will someday as they are crazy expensive.
Will clean the glue up with sandpaper hopefully.

 

[ED65]

I really want to build myself some can clamps but that's a project for the future. I don't have access to power tools and making multiple clamps by hand is a bit daunting.

I'm in the same boat, but cam clamps are not your only option. Just for very basic work you could knock up a few of these from MDF in no time (use wood for the wedges):

One step more elaborate:

 

[Kalimna]

A couple of further thoughts? Do you have any photos of the sides? It might help to advise on whether they are salvageable?
Also, unless you are working directly from a plan, then you may want to rethink the top plate braces, as there is currently no support under the bridge.

Cheers,
Adam

 

[MIGNAL]

Why does it need support under the bridge?

 

[profchris]

Why does it need support under the bridge?

Most ukes have a bridge plate, perhaps 1.5mm thick and a bit larger than the bridge footprint. I've read various explanations, but find most plausible the idea that thin hardwood tops are quite flexible along the grain compared to spruce, thus increasing the risk of the glue joint peeling away starting at the rear of the bridge. The plate stiffens that area. Fan bracing would do the same.

 

[Kalimna]

What profchris said

Adam

 

[Michelle_K]

You are right about the bridge plate. I am not following a set of plans. I tried to find free plans online but couldn't all I could find was the stew Mac template which is what I used. I plan on adding a bridge plate when I get a neck blank and figure out where the bridge actually needs to go. I did it all a bit backwards really. I should have waitied until I had all of the wood ready and I should have had a better idea of the layout of the instrument. I just wanted to get started and saw no issue in cracking on before I had all of the wood. Big mistake.
I didn't take a pic of the sides but trust me there is no saving them! They were not perfect anyway. They were not bookmatched or anything. In fact it wasn't even an instrument set of wood. I just got an offcut of walnut as scrap because it had knots in it. I cut it into three strips which took hours! Jointed two bits together and then cut them in half for the top and back. And the last piece I cut in half down the length for the sides.

 

[bugbear]

Thank you everyone for the advice and kind offers of help. Here is a picture of the walnut. I'm not even sure what kind it is. As you can see the glue is a mess. Not having a go bar deck or many clamps the braces didn't make contact across the wood so had to top up the glue which caused chaos. I really want to build myself some can clamps but that's a project for the future. I don't have access to power tools and making multiple clamps by hand is a bit daunting. But I will someday as they are crazy expensive.
Will clean the glue up with sandpaper hopefully.

You could just use weights!! Access isn't a problem for the the force of gravity...

BugBear

 

[profchris]

I didn't take a pic of the sides but trust me there is no saving them! They were not perfect anyway. They were not bookmatched or anything. In fact it wasn't even an instrument set of wood. I just got an offcut of walnut as scrap because it had knots in it. I cut it into three strips which took hours! Jointed two bits together and then cut them in half for the top and back. And the last piece I cut in half down the length for the sides.

Ah! Sounds like my first attempts.

You need to understand a bit more about grain direction and runout to help you choose your wood. "Instrument wood" isn't critical - I've made some very acceptable ukes from an old wardrobe, shelves and so on.

Ideally your plank will have vertical grain (sometimes described as quarter-sawn, but that's a complex term). In other words, if you look at the end of the plank the grain lines would run like this: ||||||||||||||||||||||||||||||

The reason vertical grain is ideal is because this shrinks least at 90 degrees to the grain direction. Once you've glued on top and back, the sides resist shrinkage, so if the wood wants to shrink a lot the plates will crack. There are ways of reducing the chance of this which you don't want to know about yet, but should learn if you decide to build more.

Runout refers to the grain when you look at a plank from the side. No runout means the grain lines run along the full length of the plank, parallel to top and bottom (ever so rare!). Runout means they are angled somewhat - in exaggerated form the side view shows grain lines like this: ///////////////////////////////

Imagine bending a thin sheet of wood with bad runout - it is likely to separate where the grain lines meet the surface, or bend unevenly or kink. So for sides, you want as little runout as you can find. (Runout can give cosmetic problems on tops and back, and seriously bad runout can lead to bridges peeling off, but those are for later on!).

Wood with a pretty grain pattern is also a problem for bending, because the pattern is caused by the grain lines wiggling up and down, rather than running along the length. This means they often end at the surface - same bending problems as before. Knots have distorted grain around them, so bending is near-impossible at those points. So pretty wood is OK for top and back, but difficult to use for sides.

The further you get from these ideals the more difficult it is to use the wood successfully.

If you can find some plain-looking walnut with not too much runout, that would be ideal for your sides.

Another option to consider is to find a model-making shop which stocks mahogany sheets - these are something like 3ft x 3 ins or 4 ins, and those with plain grain tend not to have much runout. They're already thicknessed (2mm would be ideal) and should cost under £5 each. Once bent, you could stain them to a pretty close match to your top and back, and I bet only an instrument maker would notice.

 

[MIGNAL]

I'm not convinced the bridge plate is necessary at all. Over the years I've constructed numerous types of plucked instruments, many without any form of bracing, very thin bridges with little footprint, string tensions much higher than found on any ukulele. They all seem to stand up over the years. Anyway, the bridge itself is a pretty substantial brace. I have a feeling that many Ukulele makers just follow what's happening in the guitar world, so no doubt you'll get lattice, laddder, fan, double top and all manner of different ideas. The ukulele isn't a guitar though. For one thing they tend to use hardwood for the soundboard. Apart from a mere handful of guitars in the 19th century virtually no one uses a hardwood for the soundboard. Some things will transfer across, some things won't.

 

[profchris]

I'm not convinced the bridge plate is necessary at all. Over the years I've constructed numerous types of plucked instruments, many without any form of bracing, very thin bridges with little footprint, string tensions much higher than found on any ukulele. They all seem to stand up over the years. Anyway, the bridge itself is a pretty substantial brace. I have a feeling that many Ukulele makers just follow what's happening in the guitar world, so no doubt you'll get lattice, laddder, fan, double top and all manner of different ideas. The ukulele isn't a guitar though. For one thing they tend to use hardwood for the soundboard. Apart from a mere handful of guitars in the 19th century virtually no one uses a hardwood for the soundboard. Some things will transfer across, some things won't.

You could well be right about necessity. I've made a couple of ukes with no bridge plate and they've held together (but I've been making for only about 6 years, so I don't know about longevity). But these ukes sounded "jangly" (lots of high overtones?) and showed marked humping behind the bridge and dipping in front. If mahogany (say) is thin enough to work well as a top then it's noticeable less stiff longitudinally than softwoods.

I suspect the "standard" uke bracing patterns which use a bridge plate need it to control these effects, so that if the plate is omitted the bracing needs adjusting.

On Michelle's top I think I'd add a transverse brace at around the bridge location, maybe just in front, and probably shave down those two longitudinal braces to compensate. You've much more experience - what would you add or modify?

 

[MIGNAL]

I may not add anything but I've no idea how stiff that piece of wood is or it's thickness. I'm just speaking in general terms. The soundboard distortion that you refer to happens with instruments that have fan bracing. After so many years they usually settle down and the distortion doesn't really get much worse. Of course it depends on just how far the maker has taken things. A typical Torres guitar has a soundboard that is under 2 mm's, with bracing that is no more than 2.5 mm's high. Some of his soundboards are closer to 1 mm than 2. Sides that can be shockingly thin. If you look at instruments like the vihuela or baroque guitar you get a feeling of just how much you can push these things. It's amazing how little wood exists on those bridges yet they hold some 33 Kg of total string tension. The bridges with the 'tunnels' even less surface area, hardly anything. All held on with a smear of animal glue. If you gave that information to someone who just makes modern guitars it wouldn't compute. He would likely state that the bridge would be off in a matter of days if not hours. That's because they have no experience outside of their 'modern guitar bubble'. Same with zero bracing. They'll probably state that it would lead to terrible tone, uncontrolled. It doesn't.

 

[NazNomad]

Worst (or is it?) scenario, shove a sound-post in it.