An opinion please on bowl-backed mandolin

[Pelican tree]

Well, you seem to be moving very quickly, Pelican, you'll probably be ahead of me this time tomorrow. Since we're talking about a bowlback here, you better listen to someone better acquainted with them, all my experience is with carved archtop mandolins. But if I had to say one or the other: No, don't move it under full tension. Re the harmonic, you don't have to play the harmonic; if using a tuner, it should show e open string, for example, dead on e, and e at the 12th fret the same(of course, it will actually be one octave higher). All this info will be much clearer after you've done it a few times(about where to draw the line between perfection and practicality).

There are a number of Mcafe members in Oz, so if you mention your general location, there may be someone local who can assist . Good luck.

Thank you Benny, that's funny, yes, moving quickly, but into unknown territory! So, to protect the mandolin from my eagerness to work on it, I have returned it to it's case, at least for now. I'm really enjoying learning about it and am starting to understand that it is much more complex than it appears, with every component requiring knowledge, which I don't have.

Yes, tuning it does sound easier without the harmonics, especially since I've only just found out exactly what harmonics are. Fascinating really! I like physics. Perhaps I can slowly increase the tension of the strings up to the correct pitch while regularly comparing the open pitch with the 12th-fret pitch, and adjusting the bridge as I go, so that I sneak up on it? It also occurred to me that as a beginner, maybe I will mostly be fretting the first few frets only, in which case the accuracy further up the fret board will not be as crucial, but I don't really know.

Our of curiosity, I have just searched for carved archtop, mandolins. They're beautiful, real works of art!

Thanks again, Paul.

[Pelican tree]

The bend (cant) in the soundboard of Italian-style bowlbacks is there to enable a greater downward pressure on the bridge, and thus greater volume. The shape of the soundboard is such that it also arches downward from the center line, so that the strain on the top is not taken by the bracing alone, but also by a sideways thrust against the outer rim of the bowl. Due to the shaping, the whole structure is involved in distributing the strains involved.

There are a couple basic styles of bridge for these instruments. Some have a slot made to hold a saddle, usually ivory, bone or metal wire. This style has slots cut in the wood of the bridge behind the saddle, which serve only as string spacers. Sometomes the saddle is intonated a bit.

The other style has the intonation cuts carved into the bridge itself, the notches for the strings cut into the intonated sections of the bridge.

Bridges are usually pretty low, and not particularly massive. Of course, they are fitted to the curve of the top at their ideal location. Good idea to have a professional do this, it'll save time and aggro.

Action is generally about 2mm over the 12th fret. While the scale is approximately double the distance from the nut to 12th fret, this is not exact, due to factors like fretting the string at fret 12, which changes the tension of the string as well as the length of the vibrating section. Get the setup done by someone who knows how. They might also want to dress the frets, and verify that the neck joint hasn't been buggered by heavy strings. FYI, neck surgery on a bowlback is complicated, expensive and not always successful, not unlike the same procedure in humans.

Hi Bob, thank your very much for such a comprehensive explanation!

I can see now that the soundboard is not actually flat along the line where the bridge must sit. I had assumed, incorrectly, that it was. Now I'm wondering if the angle is standard. If not, I assume that the bridge must be fitted to the soundboard by sanding its bottom surface.

From what you say, the soundboard is angled in two directions, one along the centre line and the other perpendicular (which is called the cant). Given that the body is also a bowl, it is quite an amazing shape overall. I can appreciate now how the cant increases the pressure on the bridge. It's really a very clever design! It reminds me of the design of an egg!

I can see why I need to find a professional. I hope I can afford to. If I understand it correctly, the bridge has to be sanded or machined so that it is the correct height to provide approximately a 2mm action at the 12th fret, and also so that if fits the angled soundboard, and also to possibly provide intonation if it doesn't have a separate saddle. And then it has to be placed correctly due to the practical factors you mentioned due to increases in the string length and tension when fretted. Wow, this really is a lot to get right!

I've had a closer look at the frets and can easily see that the first few have actually been dented by the strings, which surprised me.
I really hope that the neck is OK! I have looked it up and down and it appears to be reasonably straight and in line with the body, but I don't really know. Thanks again. I'm learning heaps.

[Pelican tree]

The bridge is German and are sometimes found on between the wars mandolins. A little odd to find it on an American made bowlback.

Cheers

Thank you Graham. I had a closer look at the bridge. I quite like it because it is metal and mechanical, however soon it will be appropriately replaced. It has the word ‘ideal’ machined or stamped into it, in a cursive style. Interesting! I’ve attached a photo. Cheers from Paul

[Pelican tree]

Late to the dance here. Ony thing I can add is this one resembles others made by (or for) Lyon & Healy. Headstock and pickguard shapes resemble their Washburn line of mandolins from the early 20th century.

Hi Jim

I’ve just discovered a sticker located inside the body at the neck joint with serial number 65062! I have no idea how I missed this yesterday apart from poor eyesight.

Do you happen to know if this is a typical Lyon and Healy number? Does it shed any light on the origins of the instrument?

I feel very curious. Perhaps I can help my father remember why it is he has a mandolin and where it came from. He doesn’t play.

Thanks, Paul