Australian/New Zealand Luthiers Forum

Started work on an arch-top mandolin prototype a couple of weeks ago for Tony O'Neill, who did a concert for us at Port FairyFolk Festival.

This is somewhat of a daunting task -
a) because we've never done archtops before and

b) The reason Tony wants a new mando is that his Gilchrist costs as much to insure to take it overseas as it'll cost for us to build him a new one.

So when completed it'll compared directly to one of Steve Gilchrist's. (we'll be able to measure it and have a good squizz at it though)

Still, it's been fun liaising with Tony and throwing a few ideas around and coming up with a design that he's happy with.

It's going to be based on an arch top jazz guitar and will be the same width as a Gibson F5 and about an inch shorter.

Instead of traditional F holes it's getting Rickenbacker type sound holes.

Sitka Top, Blackwood back and sides, Cumberland Acoustics bridge and Randy Allen cast tailpiece and banjo frets.

I've been using Graham MacDonald's book as a reference which is excellent.

I've rough carved the back and top. Did this by hand with a gouge and finger planes. It takes forever but is quite enjoyable. (mind you I did buy a buy an angle grinder today for any future ones )

Here's some pics.









Bob

Bob,

That's looking good. It's always fun and interesting to make something new and different.

That really is a daunting build Bob. Lovely wood you've chosen there. Looking forward to the progress pictures on this one.

Welcome to the dark side Bob, you know you will not be able to escape......

I got a carving bit for my angle grinder to speed up the carving. Works well but one slip and well........

Looks good. I think one hand carving of a blackwood back will send you to the tool shop for an Arbortech angle grinder blade real quick

If you get stuck anywhere just drop me a line

graham

Looking great Bob!!!!

You have gotten pretty far with it already in seemingly no time at all.

That's an incredible spruce top, Bob. It's got the most dark, dense late growth I've seen in any spruce for a while. It must be really stiff?

Are carved mando tops selected for stiffness (as one criteria) similar to flat tops? How does stiffness work into a mando top selection?

Larry, this is the first arch top instrument I've made so I'm still trying to figure out all this stuff as I go along.

The stiffness does play the same sort of role as in a flat top but I wouldn't have a clue whether this piece is stiff or not yet until I hollow out the inside of the top.

I don't know how mando builders select their top wood as it's a bit hard flexing a piece of spruce that's an inch thick.

Maybe Graham MacDonald will chime in here.

That piece came from Tim Spittle and was advertised as 20 year old Sitka, so I guess it's been kicking around for a while.

Cheers

Bob

As Bob says, you certainly can't flex a carved soundboard blank. I suppose there are scientific ways of measuring it, but I just start carving and stop when it gets thin enough

I reckon that is about when I can feel a bit of flex around the edges and the basic tap tone (hold at 10 o'clock, tap at 4) seems about right, based I what I can hear and how that co-responds to previous info I have noted down.

If you are going to use f holes of some kind along the sides of soundboard rather than a single oval or round hole, I would suggest making the centre under the bridge no less than .180" / 4.5mm with the recurve 40% less than that. Too thin is often worse than too thick

Good luck with it

graham

A few thoughts ...

If you're into cat-eye sound holes; have a 'google' at german 'mandolines' esp. Höfner and Framus 1950's mandos, many of which have bound cat eyes. They can look quite elegant ( when they resist the temptation to cut cat-eyes AND round holes on the same instrument ... )

And remember, as legend has it, all Gilchrist had to guide him in making his first mando was a black and white photo on a Bill Monroe L.P.

Good luck, I'm sure based on your past work it's going to be slick and a very sweet little diversion for you and with company like that, maybe next you can build a classical for someone who can't afford to insure their Smallman !

Cheers, A.P.

bob wrote:(we'll be able to measure it and have a good squizz at it though)

I don't think I'd do that if I were you!
(Uhm!! How do you Australians squizz something anyway!)

Looks really nice Bob! Beautiful cut to it! Outstanding looking top!

Well it's almost finished.

Got the back glued on today so there's only the back bindings to do, install the machine heads, some finish and we're done.

It's been a very interesting process throwing up a lot of problems and questions that you simply don't come across building flat top guitars.

If it doesn't fall apart when we string it up it's heading to Ireland and then Europe for a couple of months.

It's looking like an instrument there Bob. Would you say it's a difficult thing to build, or is it just different? Any plans on doing another now that you've wet your feet?

It's just different Allen, no more difficult but Dave and I spent a lot of time looking at things and there was much scratching of heads.

We've already started numbers two and three, one of which is a flat top mando in the same shape and the other is going to be another arch top to try and develop what we did on the first one further.

What there is to develop we haven't got a clue yet 'til we put the strings on the first bugger.

bob wrote:We've already started numbers two and three, one of which is a flat top mando in the same shape and the other is going to be another arch top to try and develop what we did on the first one further.

What there is to develop we haven't got a clue yet 'til we put the strings on the first bugger.

Ahhh the dark side takes over........

Great looking instrument Bob, what are your finishing plans?

Mirotone pre-cat laquer on this one Sebastiaan.

We've just about finished the tin that we have and then we're going to try some of the Mirotone polyurethane. Apparently it's tougher, hardens quicker and it sands to a fine dust.

Dave and Bob,

Great stuff!! Can't wait to follow the banjo build

Great work guys . Looks fantastic !

Sweet!

Really nice, Bob and Dave!

Can't wait to hear it all strung up.

Dennis

It's coming along very nicely Bob and Dave ! I Can't wait
to see it strung up and makin' music !

Well it's finished and has been delivered to it's new owner.

Tony was well pleased with it from first impressions but he's got 3 gigs on this weekend to put it through it's paces so I guess I'll get a full report early in the week.

Thanks for looking.

Bloody beautiful Bob.

Cheers

Alan

Bob,

Wow - a Django Mini-Me

That looks fabulous. When are you going to do a full sized archtop guitar?

Looks great, reminds me of a couple of 50s era Framus mandos from Germany. Hope the book was of a little use

cheers

graham