All acacia (wattle we think of next?)

Tannin

I've been turning over an idea in the back of my mind for a future build. Not any time soon, understand, this one would be a few years down the track. 

I'm thinking all acacia. Blackwood and Koa are both well-known, backs and sides obviously, but both are frequently used for tops as well. But I'm thinking of a more common but less well-known acacia for the top: Silver Wattle. People say it is very similar to Blackwood in its tonal properties, and it is certainly a nice timber to work with tools. It tends to be paler in colour, which is why Blackwood is usually the first choice for fine furniture. (And guitars too, maybe.) It's readily available, though seldom cut for guitar parts. In fact there are lots of Silver Wattles right here on our own property - maybe I could use one of my own trees?



^ Silver Wattles at home on a frosty winter morning. Huon Valley, Tasmania.

For the fretboard, we are spoiled for choice. Mulga (Acacia aneura) would be first cab off the rank, but there are heaps of hard, dark, heavy acacias, nearly all of them from the deserts - and if there is one thing Australia is not short of, it's desert. Gidgee (Acacia cambagei) is well-regarded, and then there is Red Mulga (Acacia cyperophylla, sometimes incorrectly known as "mini richie"), Western Myall  (Acacia papyrocarpa) and many others. Any of those would be a good choice. Gidgee and Red Mulga are both harder than ebony! These are also all trees I know well from my years travelling the outback doing bird photography, so having them represented in a guitar I see every day here at home would be lovely. 


^ Minni richie is a type of bark with little curls on it. The term applies to half a dozen different acacias and several eucalypts also. The example above was growing along a creek near the point where Queensland, New South Wales and South Australia meet ; it is  Red Mulga.

Blackwood is a well-tested neck timber (in fact two of my current guitars have Blackwood necks) but Paul says he's happy to make necks out of almost anything so long as it's properly quarter sawn and well-seasoned. 



^ Blackwood back and neck at left. All three guitars are Matons, the other two are rosewood and mahogany (centre) and Queensland Maple (right).

As for back and sides, well I did think of Gidgee first. It's been done before apparently with excellent results but it's a bugger of a thing to work and it is so hard and heavy it will probably ring more than rosewood and be akin to ebony or African Blackwood. So I'm having second thoughts about that one - I generally prefer softer woods. Blackwood and Silver Wattle are of course sensible possibilities, and it also occurs to me that Black Wattle (Acacia Mearnsii) would be suitable, if I can find a bit that's borer-free. Blackwood, Black Wattle and Silver Wattle are all very common trees in southern Australia so supply shouldn't be an issue. 

Anyway, I spoke to Paul Mineur about it yesterday (Paul has made two of my guitars) and he's happy to build me another and thinks all-acacia will be a nice theme. At present I'm thinking grand auditorium or OM size and a slightly longer scale length (685mm, 27") with a view to tuning it in D, probably on standard strings (12s) or possibly 13s. I reckon hardwood tops go better when they aren't too small, but I'm getting too old to want too many more dreadnoughts and jumbos.

He thinks my trees might be a bit small to make an orthodox two-piece top out of, but I'll make some measurements and we will see. Like most wattles (but not the desert ones) Silvers are fairly short lived and one blows over every six months or so so I wouldn't have to cut a good tree down. We will see.

drofluf

Sounds a great project; any chance of sourcing all of the wood from your estate?

earwighoney

Tannin said:

As for back and sides, well I did think of Gidgee first. It's been done before apparently with excellent results but it's a bugger of a thing to work and it is so hard and heavy it will probably ring more than rosewood and be akin to ebony or African Blackwood. So I'm having second thoughts about that one - I generally prefer softer woods.

Gidgee is heavier than ABW.  I have tried a few ABW guitars and they are spectacular but very heavy.  I imagine Gidgee would need to be thinned quite a lot and could be a little prone to cracking.  I think it would make a great fretboard/bridge set for an acoustic guitar though.

Tannin

^ Cheers @earwighoney. The Wood Database lists Gidgee at 1150kg/m3 and African Blackwood at 1270 - but numbers of that nature are just averages and if I'm any guess the Gidgee number will be an average of a very small sample, so not very reliable. The weight was the first thing Paul said too. But I'm a former 1970s Les Paul owner so it would have to be a solid-body acoustic to rival that mega-heavy boat anchor! In any case I always play sitting down. 

But on the whole I think Gidgee might not be ideal. Something in the medium-weight category appeals more. 

Hi @drofluf - that's a notion. Yes, it should be possible, but with limitations.

First, we might be pushed to 3-piece tops and backs (which apparently makes bugger-all difference to the sound) because the trees are mostly not big enough yet. They are mainly regrowth from the dreadful 1967 bushfire, and fairly slow regrowth because they are mainly on the steeper, rockier, drier and least fertile part of the land. The lower, flatter parts were cleared many years earlier to plant an orchard, but are in any case not overly fertile - Huon Valley soils aren't, they just happen to suit apples and pears for some reason.

The other reason for the slow growth is that the trees suffer from "lock up". This is a condition well-known to foresters where there are many young trees too close together and they starve one-another of light and nutrient, resulting in unhealthy trees and very slow growth. It is common after clearfelling or a natural disaster (such as a big fire or flood). Foresters growing production timber thin out the trees by cutting out the weakest ones (exactly as a gardener thins out his carrots after germination). Left alone, nature  will do the same job, but very slowly. The weakest ones die eventually, and over (say) 100 years you get back to healthy forest with a reasonable number of trees spaced far enough apart to grow big and strong. That process in ongoing here - little by little the bush is healing itself. There has been a noticeable improvement just in the 5 years I've been here. I'd be reluctant to cut down a healthy tree to make a guitar from it, but we see half a dozen medium-big ones fall of their own accord each year. Trouble is they tend to be quite tall (30 or 40 metres typically) but quite slim (half a metre, give or take). 

The second limitation is species. There is only one acacia of any size (Silver Wattle). That would be the only candidate for a top. Come to that, there is no reason you couldn't make the whole guitar out of it - Blackwood is, after all, commonly used for tops, backs, and necks, and Silver Wattle is similar. It's a bit soft for a fretboard  but would maybe do at a pinch.  There is also Prickly Moses (Acacia verticillata) a medium shrub easily big enough to make a fretboard from. Is it suitable? No idea, but I have put bits of it through the chipper which seems to think they are fairly hard. We have Common Dogwood (Pomaderris apetala),  a tall shrub  or small tree, growing along the creeks. I've never heard of the timber being used for anything but it seems to be very hard and might be useful. There is also lots of Crack Willow (Salix fragilis), an invasive feral  tree useless for anything. As I find time, I am getting rid of it but it's a big job which will take years. 

Finally there are the eucalypts, mostly Messmate Stringybark (Eucalyptus obliqua) and Manna Gum (Eucalyptus viminalis). Manna Gum timber is not particularly valued, but Messmate is one of the four or five most-harvested eucalypts for construction timber and is well-regarded as a timber for back and sides. Eucalypts generally are not often favoured for necks because of stability concerns, but properly selected and dried they are sometimes used.

I see that Taylor have recently started using Tasmanian Blue Gum (Eucalyptus globulus) for the fretboards of their American Dream models, albeit dyed black. I have not noticed any Blue Gums on the property but it is common in the district. It is very similar to Indian Rosewood in terms of weight and hardness. I don't have weight or hardness figures for Messmate but it wouldn't be so very different. In fact when you buy Messmate in timber yards to build a house or such, it is sold as "Tasmanian Oak" (here) or "Victorian Ash" (mainland Australia) mixed in with four or five other eucalypts including Mountain Ash, Alpine Ash, and Blue Gum - you can't tell them apart once milled and for most purposes it makes no difference.

Jez6345789

Interesting project and as I understand it Australia is like Acacia Central with the highest number of species in the world. 
I think all the ones you suggest would make an interesting guitar but I have to say if I lived in Acacia Central I think I might want to find something a bit out of the ordinary Australia is spoilt for really lovely woods.  As for Eucalyptus, I believe Taylor is fuming with ammonia rather than dyeing the wood or they were a while back as they were getting it from a Spanish Supplier as we have tons of Eucalyptus in Spain a left over from the Franco era I believe. I have a couple of nice fumed back and side sets with flame from that supplier.

Anyway when it gets going keep us posted looking forward

Tannin

^ Wow! Ammonia. Very interesting!

Acacia central? Indeed. Well over 90% of all acacia species are native to Australia (over 900 different ones), with several dozen others native to the Pacific islands, Asia, and a few odd-bods in far away places such as Indian Ocean islands and Madagascar. 

How far does one explore beyond the ordinary? It would be nice to go right out on a limb (er .. so to speak) and build from four species hitherto unknown as tonewoods. (It wouldn't be difficult to find four such, or forty for that matter, though finding things in sizes big enough to make an orthodox two-piece top or back in might be a bit harder.)

On the other hand, a hand-made guitar takes several years from order to finished product and costs a minimum of $6000 (more than £3000)  so we need to be a little bit cautious!

PS: Assuming I go ahead with this - it's just an interesting thought-experiment at this stage - by the time we see any concrete progress, posting an update here might count as a necro-bump.  




^ Mulga  (Acacia aneura), an excellent fretboard timber, dark red in colour, hard and heavy. Mulga grows over vast areas of arid Australia and regenerates readily, albeit fairly slowly. The trees seen here are perhaps 30 years old and won't grow much taller than they are, though they will get thicker.