Substiitute Bracing

[ernie]

Currently building 2 new models 1 is a 24in scale copy of a Cl giannini guitar that is lightly braced and another 23in scale 4 string tenor guitar. The 4 string has a carpathian spruce top and the CL gtr is WRC. I just bent the falcate braces for the 4 string using englemann spruce, which came out ok. I am going to use flatsawn balsa and cf for a lattice brace on the WRC CL .My question is can you substitute other woods for falcate bracing e.g I have some good 1/4 sawn WRC , as well as sitka, adi, and lutz spruce.For the lattice . I read of other luthiers just using spruce for the lattice bracing minus the CF. Would any of you comment on other woods for a non cf lattice brace besides spruce? . Can one use WRC , but then how thick ?? For the falcate gtrs , what other woods could be used besides king billy pine or spruce? . thanks

[DarwinStrings]

G'day Ernie, I have been using Queensland Silver Ash for my secondary falcates to get the tight bend (sitka for primary). It was one of Trevor's recommendations and tested as 18.8 Gpa Elong at 769 Kg per cube metre. If you can bend your spruce to suit though you may as well use that.

Jim

[ernie]

Thanks darwin I used englemann for the long falcate ,it/s softer than sitka and bends readily ,dirt cheap here in the usa at home stores/lumberyards.My laminates were just over 1/16in or abt 1.7mm I put a center piece of h.mahog in for insurance. The tighter c brace was all englemann. Am not familiar with the ash you mentioned. Most n. american ash is med to dense hdwd , but bends vy easily cold. when vy thin.

[Trevor Gore]

My question is can you substitute other woods for falcate bracing e.g I have some good 1/4 sawn WRC , as well as sitka, adi, and lutz spruce.

WRC has similar mechanical properties to King Billy, the big difference being that KB bends, whereas none of the WRC I've tried will. So I'd say stick with the spruces if you have some that will bend. Some does, some doesn't, even in the same species.

I read of other luthiers just using spruce for the lattice bracing minus the CF. Would any of you comment on other woods for a non cf lattice brace besides spruce?

For the same strength and stiffness, spruce will pretty much always give a lower mass outcome, which is why it is almost universally used for bracing in non-CF builds. The argument and testing supporting that is in Section 4.4.7.

[kiwigeo]

King Billy bends like melted butter.....

I haven't had much luck with spruce.....the stuff Ive got is stiff so it wont bend unless I take it down to The Tax Department.

[ernie]

Thanks trev, that/s what I noticed on 2 websites the builders were using spruce lattice for the build minus the cf. I/m following the balsa cf route on this small classical . Very cute kiwi, I did get my local tax dept to bend lol for $400 when they jacked up my taxes. A nasty letter and documentation seemed to work here. Guess it/s vy tight in OZ.I looked up the density of oz silver ash, and it seems similiar to the lower density ashes we have here. There are 7 types in our area. The colour is slightly different. Will rip some to try ,. it bends quite easily cold at 1.7mm. Will try it on the tight c bend next. I scored a 2 by 4 wrc the other day so I might try some experiments on bending .Coming from BC I did see some bending of traditional northwest coast WRC boxes.They were steam bent an vy attractive.