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Bass Builder Undertakes Mandola Build
Hello all,
I am new to the forums here, so first, a little bit about myself:
My name is Jake, I am a bass (solid-body electric) builder in Chicago. I started out as a one-man operation, but over the last 6 years, we have grown to four-man shop building around 200 instruments a year. The company is called Serek Basses for those curious.
But I didn't come here to self-promote. Recently, I have become a bit burned-out running the business. I spend way less time these days working with my hands, so I started dreaming up a personal project to re-ignite my passion for woodworking; something to challenge me as well.
It turns out I have also recently become completely enchanted with the Mandola. Something about its sweet, deep sound really calls to me. I also appreciate that it doesn't quite fit in; its a bit of an outsider. I owned a cheap Mandolin many years ago, but could never quite wrap my sausage fingers around it comfortably, so I have high hopes that the Mandola will be my glass slipper.
Now, on to the build: I have designed a flat-top, two-point, oval-hole Mandola with a 17" scale. It will be a fairly traditional build, however, I am going to lean on my instincts along the way. I realize some folks may balk at some of the choices I make, and that's okay. This is an experiment, and while I have complete respect for tradition, it is also important that I try things my own way.
I have attached my drawings and I will post my progress along the way. I look forward to hearing what you all have to say!
TL;DR - Bass builder attempts to build Mandola, kinda winging it so hang on tight!
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Re: Bass Builder Undertakes Mandola Build
Welcome to the Cafe! That looks like a nice design (reminds me of a Kimble). I have built flat top mandolins and guitars and I would point out that they are not "flat". A 15 or better yet 12 foot arch should be induced into the arch of the top with the bracing of your choice. X-braced or H-braced or what ever else you come up with. This can be done with a hollowed disk (of plywood) and a go bar deck. The braces can be shaped using the same disc with sandpaper applied to it.
LMI sells them...
https://www.lmii.com/radiusing/2633-...hing-form.html
Good luck with your build, keep us informed.
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Re: Bass Builder Undertakes Mandola Build
Or, if you don't want to buy or make a go-bar deck for one instrument, you can make a couple of radiused clamping cauls out of a 2 x 4. You can stick some sandpaper to the face of a caul to use to radius your braces.
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Re: Bass Builder Undertakes Mandola Build
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Re: Bass Builder Undertakes Mandola Build
Graham Macdonald's book the Mandolin Project might be useful to you. It is all mandolin's but they can be scaled up.
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Re: Bass Builder Undertakes Mandola Build
[duplicate post] Can't figure why that happens sometimes.
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Re: Bass Builder Undertakes Mandola Build
Reminds me of a Vega 2 point shape, but a shade sleeker. I like the look of it.
Looks like the bridge will land at the widest part of the top. I've always thought that to be a good thing.
Have you decided on woods? Bracing? Body depth?
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Re: Bass Builder Undertakes Mandola Build
Wellcome and keep going. Nice body shape but I would check the headstock design with real set of mandolin tuners (or drawings), the holes look too far inward for A style tuners and the headsocka bit short so the shafts and plates footprint may interfere weirdly with the outline (think of worm over/under tuners, the shafts and plates on the underside are offset from post positions to one or the other side)
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Re: Bass Builder Undertakes Mandola Build
I know you don’t have any fret markers on your drawing but since you are a bass maker if you do intend to put in markers remember the standard markers for mandolin fretboard include a 10th fret as opposed to a ninth fret marker for basses and guitars.
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Re: Bass Builder Undertakes Mandola Build
Thanks for all the feedback and support so far!
Quote:
Originally Posted by
Jim Garber
I know you don’t have any fret markers on your drawing but since you are a bass maker if you do intend to put in markers remember the standard markers for mandolin fretboard include a 10th fret as opposed to a ninth fret marker for basses and guitars.
Thanks for pointing this out, I had noticed this as I started looking at pictures for inspiration. Definitely did a few double takes to make sure I wasn't losing my marbles!
Quote:
Originally Posted by
Charles E.
Welcome to the Cafe! That looks like a nice design (reminds me of a Kimble). I have built flat top mandolins and guitars and I would point out that they are not "flat". A 15 or better yet 12 foot arch should be induced into the arch of the top with the bracing of your choice. X-braced or H-braced or what ever else you come up with. This can be done with a hollowed disk (of plywood) and a go bar deck. The braces can be shaped using the same disc with sandpaper applied to it.
The Kimble is definitely an influence here! I did go ahead and order a 15' dish from LMII. I know this won't be my last Mando build...
Quote:
Originally Posted by
rcc56
Or, if you don't want to buy or make a go-bar deck for one instrument, you can make a couple of radiused clamping cauls out of a 2 x 4. You can stick some sandpaper to the face of a caul to use to radius your braces.
This is gold. I will eventually make a deck, but might do this for this first go-round.
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Quote:
Originally Posted by
rcc56
Reminds me of a Vega 2 point shape, but a shade sleeker. I like the look of it.
Looks like the bridge will land at the widest part of the top. I've always thought that to be a good thing.
Have you decided on woods? Bracing? Body depth?
About to answer these questions in my first progress update!
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Re: Bass Builder Undertakes Mandola Build
When you're strictly a repairman working in a basement shop with limited space and budget and you need a jig for a job you're not going to repeat often, you learn to improvise; or beg, borrow and steal ideas from wherever you can get them.
The radiused clamping caul was a trick I remembered that was passed down to me by a fellow who took a course at The Apprentice Shop 40 years ago and built 6 or 8 guitars. Yes, for regular production, a go-bar deck and dish is much more efficient, but for one instrument or the occasional brace or two, radiused cauls will get the job done. And they don't take up hardly any space. I have four of them, and they can also be used [with sandpaper] to bevel and regularize the surface of a corpus to prepare it for a top or back that's being glued on.
I've also made one or two temporary molds from rigid wall insulation board. It cuts with a utility knife, and if you get a spot that's a little off, you can make a shim that'll fit between the mold and the instrument side to correct the error.
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When I find myself wanting a tool for a job I might not do again for a couple of years, or I don't have the space or budget for it, I remind myself that Strad didn't have no belt sander; and look at what he did with a few gouges, a couple of homemade planes, and beach sand.
Torres might have had sandpaper. I remember a TV feature of the Ramirez shop from the 1980's. They were still bending their sides over a hot pipe, heated with a handheld torch or on a stove [I don't remember which].
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How many of y'all have seen a Strad up close? I have. His workmanship was so gorgeous that the shapes and craftsmanship just jumped off the table towards my eyes. I've never seen anything else like it. No, it wasn't the wood, or the varnish, and it certainly wasn't the primitive tools. It was the man.
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Re: Bass Builder Undertakes Mandola Build
Mandola looks great! Checked out Serek Basses and they look nice too...
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Re: Bass Builder Undertakes Mandola Build
Progress Report #1
First up, some specs: The back, sides, and neck of this build will be African Mahogany (aka Khaya). We use this a TON for our basses and while it isn't typically as dense as Genuine Mahogany, it is very stable if you know what to look for. I have plenty of offcuts at the shop, so I have chosen a few of the densest pieces I can find for the body and neck. The fingerboard will be Ebony and the top will be Redwood. I plan to use modified X bracing and will induce a 15' radius to the top, but not the back... more on that next.
The next choice I am making is where I may lose some of you. I have decided that instead of bending the sides, I am going to route a "dish" for my back and sides. I know, I know, the grain runs out and it's just inviting all kinds of bad, but I am an experimenter at heart, and I am going to try some of my bass-building techniques here. I also have a CNC so I can "cheat" a little bit. I also realize this means I won't be able to induce a dome on the back of the instrument, but let's see what happens!
I glued up a body blank made of two pieces of Af Mahog sandwiched with a layer of 1/16th" phenolic material in the middle. This will act as some extra support around the rim as well as an accent line. The neck blank is glued up as well.
I then went ahead and routed out the "dish." I realize this is a tedious and rather wasteful way of working, but I had the scraps, and only intend to try this for the sake of SCIENCE!
I was very pleasantly surprised when the rim didn't shatter while routing, I took care to alternate routing the inner cavity and outer edge. I did have some bit slippage toward the end that crushed a nice gouge into the bottom of the dish, but it didn't poke all the way through and I will be able to repair it later. The rim is 1/8" thick near the points and tapers to 3/16" as it approaches the tail block. Since there is naturally more end grain as the body widens out toward the tail, I figured some extra material would be ideal. The back is 1/8". I don't have a lot of references, but "the dish", as it is now dubbed, has a very lively, pleasing tap tone to my ears!
That's all for now, sorry if this is long-winded, I just want to be thorough!
In the headphones today: Jerry Garcia / David Grisman
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Re: Bass Builder Undertakes Mandola Build
Quote:
Originally Posted by
HoGo
Wellcome and keep going. Nice body shape but I would check the headstock design with real set of mandolin tuners (or drawings), the holes look too far inward for A style tuners and the headsocka bit short so the shafts and plates footprint may interfere weirdly with the outline (think of worm over/under tuners, the shafts and plates on the underside are offset from post positions to one or the other side)
Thanks for the heads up. I actually found out this headstock (my bass headstock) will work with F-style tuners pitched in at that angle. Still waiting on them to arrive to be double sure, but the math worked out so far!
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Re: Bass Builder Undertakes Mandola Build
Actually, your "dish" idea isn't new. A fellow by the name of Orville Gibson made his earliest mandolins using that idea, before the "business partners" [actually they were vultures] came along and started a factory. I believe his original idea was to carve everything, including the neck, out of a single piece of wood; but few, if any, were actually built with the integral neck.
I'm a repairman, not a builder, so I'm not qualified to give advice about this, but I've heard that redwood can deviate considerably in density and stiffness from spruce, and that this must be taken into consideration when you determine the thickness for your top. At least one of our builders has experience with redwood. I think it was James Condino. He might be able to give you some pointers.
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Re: Bass Builder Undertakes Mandola Build
Phil Crump also has experience with redwood. He made my OM with an old growth redwood top. It’s very nice. And, incidentally, a few years ago Phil had two redwoods fall in his yard; one on his house and one on his shop….
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Re: Bass Builder Undertakes Mandola Build
Dear lord I hope he was able to at least salvage the timber for future use!
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Re: Bass Builder Undertakes Mandola Build
Progress Report #2:
Spent some time on the top the last couple of days as well. I first sent the two halves through my drum sander to smooth out the rough faces and joined the edges. For the glue-up I used the tent method. Worked great!
The next day I was able to route out the rosette and sound hole. Here again, I was able to take advantage of my CNC. I was originally planning to use ebony for the simple rosette, however, since I still don't have a bending iron, I settled for more of the same phenolic material I used on the rim of the dish. I used the leftover cutout from the sound hole as a bending form along with a heat gun. I then used a whip tip to bead some medium CA into the rosette channel and called it a day. The phenolic is quite stiff material, so I am hoping this will reinforce the sound hole a bit.
On that note, have any of you ever tried laminating some extra veneer behind the sound hole? Not sure if it is necessary, but if it won't affect the resonance of the top, I may as well add the extra strength...
In the headphones today: Tone Poems by David Grisman & Tony Rice
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Re: Bass Builder Undertakes Mandola Build
Many classical guitar builders use a similarly shaped piece to reinforce under the rosette. You don't need much.
Steel string guitar builders generally just use a couple of thin rectangular stiffeners, and let the upper face brace and the X handle any area not covered by the stiffeners.
Google "guitar bracing patterns," and you'll see all you need to see in about 45 seconds.
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Re: Bass Builder Undertakes Mandola Build
Perhaps you have used the same brand of CA on this wood before and are confident of success, but if not, there is a chance that the top wood may be discolored by the CA used to set the rosette. A test on scrap would reveal whether or not.
That is why I no longer use CA for that purpose and instead use rather thin high clarity hot hide glue on the warmed parts (to give it time to seep in like CA).
Hopefully you will not have problems with the cedar being colored by the CA.
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Re: Bass Builder Undertakes Mandola Build
Don't know if you are to thickness yet. If you are using Western Red Cedar, it should be 20 percent or so greater thickness than a similar spruce top to get similar stiffness. I have heard people suggest larger numbers for redwood but I have not had experience with it directly.
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Re: Bass Builder Undertakes Mandola Build
Quote:
Originally Posted by
CarlM
Don't know if you are to thickness yet. If you are using Western Red Cedar, it should be 20 percent or so greater thickness than a similar spruce top to get similar stiffness. I have heard people suggest larger numbers for redwood but I have not had experience with it directly.
Yep, I've shipped redwood mandolins nearly 8mm thick in the center. The whole "redwood mandolins sound great but don't develop over time, may wear out or cave in over time" myth is based on people carving the redwood way too thin, IMHO. This one is extremely loud and responsive, .300" thick in the center, all the way from the neck to the tailpiece.
https://youtu.be/r_fD7dxzRSc
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Re: Bass Builder Undertakes Mandola Build
Quote:
Originally Posted by
sunburst
Perhaps you have used the same brand of CA on this wood before and are confident of success, but if not, there is a chance that the top wood may be discolored by the CA used to set the rosette. A test on scrap would reveal whether or not.
I did think about this and ended up having a little squeezeout, but since I had some meat left the thickness sand, it came off fairly quickly. I find this to be the beauty of the Medium vs the Thin CA, it doesn't soak in as easily before it cures.
Quote:
Originally Posted by
CarlM
Don't know if you are to thickness yet. If you are using Western Red Cedar, it should be 20 percent or so greater thickness than a similar spruce top to get similar stiffness. I have heard people suggest larger numbers for redwood but I have not had experience with it directly.
I took the top down to just over .11". I don't have much experience with Redwood, but the board feels fairly stiff, and I think as long as I carve my braces right, it should hold.
On that note: Can anyone give me guidance for ideal brace dimensions? I have gathered that they should be about 1/4" wide and around 1/2" tall at the highest point. Should I be scalloping them toward the ends, or perhaps more gradually sloping them? I realize there isn't necessarily a right answer, but any guidance is appreciated!
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Re: Bass Builder Undertakes Mandola Build
Quote:
Originally Posted by
rcc56
Actually, your "dish" idea isn't new. A fellow by the name of Orville Gibson made his earliest mandolins using that idea, before the "business partners" [actually they were vultures] came along and started a factory. I believe his original idea was to carve everything, including the neck, out of a single piece of wood; but few, if any, were actually built with the integral neck...
You beat me to it. The patent shows as expired lifetime. At least he doesn't have to worry about Gibson knocking on his door. :cool:
https://patents.google.com/patent/US598245A/en
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Re: Bass Builder Undertakes Mandola Build
Quote:
Originally Posted by
Madphingers
On that note: Can anyone give me guidance for ideal brace dimensions? I have gathered that they should be about 1/4" wide and around 1/2" tall at the highest point. Should I be scalloping them toward the ends, or perhaps more gradually sloping them? I realize there isn't necessarily a right answer, but any guidance is appreciated!
1/4" is a good width. Any narrower and there isn't mach glue surface to hold them in place. Braces over 5/16" wide are more-or-less specialty applications, and although they can be seen in some Martin guitars there are also many guitars with no braces wider than about 1/4" to 5/16.
Ends should be tapered to "nothing" and in some cases tucked under linings so that the ends are not prone to popping loose when there is pressure or impact to the plate. I prefer fairly long tapers, others like shorter tapers.
As for brace height, that is determines by the overall stiffness of the plate (top or back) desired. Start with tall braces and then shave them down until your plate stiffness suits you. Without much experience with braced plates (I assume) you might want to consult with someone who has such experience, in person, so that they can flex and judge stiffness.