Octave mandolin

[Bob_H]

I have been getting a great deal of pleasure from learning to build and play the mandolin, so have decided to add an octave mandolin to the family.

It is a 20 15/16 inch scale length, lattice braced with a pin bridge, drawing on the techniques and plans in Graham McDonald's "The Bouzouki Book". Sound board is sitka spruce, back and sides claro walnut, neck is Queensland maple and the fingerboard lacey sheoak. Headstock veneer, rosette and end graft will be river oak and have yet to decide on the bindings (either dark - ebony / blackwood - or light - maple).

Finished refining the bracing and attached the sound board to the sides this afternoon.

[amir]

Beautiful work

it's a very pleasing shape

[kiwigeo]

Nice work Bob.

If you're going with ebony for the bindings be prepared for some heart aches bending the stuff.

[Bob_H]

Nice work Bob.

If you're going with ebony for the bindings be prepared for some heart aches bending the stuff.

Thanks. I have used ebony binding a few times now, and found the bending to be a bit tricky, and that care is needed to stop black dust marking your soundboard. The result can be very nice though!

[Mark McLean]

That is a lovely looking instrument Bob. I did one like that from GM’s book a few years ago and really enjoyed it ( my first build that wasn’t a guitar). That stripy walnut is pretty stunning. With black bindings it would look very smart. That shape does not require as much tight bending as a guitar shape so ebony will probably be fine. Yes it can be cranky to bend, but on the other hand it is very forgiving if you do need to patch or hide a break or a join due to a bending mishap. I have done ebony bindings on a cutaway before and found it was not too hard to manage. Unkind folks have pointed out that a perfect ebony binding ends up looking a lot like black plastic - which some people will assume that you have used. But we will know the truth……

[Bob_H]

That is a lovely looking instrument Bob. I did one like that from GM’s book a few years ago and really enjoyed it ( my first build that wasn’t a guitar). That stripy walnut is pretty stunning. With black bindings it would look very smart. That shape does not require as much tight bending as a guitar shape so ebony will probably be fine. Yes it can be cranky to bend, but on the other hand it is very forgiving if you do need to patch or hide a break or a join due to a bending mishap. I have done ebony bindings on a cutaway before and found it was not too hard to manage. Unkind folks have pointed out that a perfect ebony binding ends up looking a lot like black plastic - which some people will assume that you have used. But we will know the truth……

Thanks Mark. The walnut is interesting - I bought it a few years ago and had forgotten the striped effect - I am hoping it will really pop with a glossy shellac finish. It will need some serious pore filling though. Re ebony, I used ebony for the bindings on my last mandolin, and was very happy with the effect - I initial though "smooth as butter" but perhaps plastic is more apt.

[Mark McLean]

Ahh, I can see that you don’t really need any advice from the rest of us to pull off a great result. Pore filling and then shellac? Will look great, but lots of work. I thought you had become a convert to hard wax oil finishes (and I see that bottle of TruOil on your shelf)?

BTW, it looks like you did a solid neck block for your octave mandolin, or did you try Graham’s hollow block idea? Any thoughts on this? Maybe solid could be good for sustain, but is it weighty?

I love the look of that body shape. The only annoying thing about it in a bigger size is that it doesn’t balance well on my knee when playing it.

[Bob_H]

Ahh, I can see that you don’t really need any advice from the rest of us to pull off a great result. Pore filling and then shellac? Will look great, but lots of work. I thought you had become a convert to hard wax oil finishes (and I see that bottle of TruOil on your shelf)?

BTW, it looks like you did a solid neck block for your octave mandolin, or did you try Graham’s hollow block idea? Any thoughts on this? Maybe solid could be good for sustain, but is it weighty?

I love the look of that body shape. The only annoying thing about it in a bigger size is that it doesn’t balance well on my knee when playing it.

Thanks Mark, but all advice is gratefully received (and generally needed!). I have previously used TruOil, and have recently Osmo PolyX. Very happy with the results of the Osmo, particularly in view of the feel and the ease of application, and will definitely use again. I tried to research pore filling under a hard wax oil finish, and couldn't really get a good feel for best practice, except a general vibe some common filling practices (like epoxy) would probably not go well with the Osmo as even absorption would be hindered by the fill. The claro walnut has some big pores, and I want to fill to get a smoother finish, so I thought hardened shellac over an epoxy fill. I don't really french polish, just wipe on and then wet sand with paper and then micromesh (that's what I did with the mandolin above) and have been happy with the return on time invested.

I went with the solid neck block for the OM, with a mortise and tenon attachment. I like the hollow block idea but opted for simplicity and robustness. The neck block is a birch ply (from Guitar Templates) so pretty light weight.

[Bob_H]

I have closed it up, and trimmed the overhang. I have finished most of the shaping work on the neck, attached a fretted fingerboard, and bolted it up to check fit. Happy with how it is coming together, so time to settle on binding and rout some binding channels.

[Mark McLean]

Looking good Bob. I also like to build with a zero fret, but it is not very commonly seen. Either ebony or maple bindings would be nice on that one. Difficult decision!

[Bob_H]

Binding on - went with the lighter colouring of the maple. Quite pleased with how it is progressing!

I am a big fan of the zero fret - I just can't think of any really good reason not to use one, and I have used on guitars, mandolins and ukuleles. I have been very happy with their playability and the ease of setup.

[DickHutchings]

Beautiful work there! I think you've convinced me to try a zero fret on my current dread.

[Bob_H]

Hard shellac finish, neck on, tuners fitted. Will let it rest for a day or two before fitting the bridge and saddle. I find this part of the prcoess very difficult, as I simply want finish as quickly as possible so I can play the instrument and hear its music!