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Hey Guys and Gals,

I'm planning on building #'s 1 and 2 consecutively (one 'trailing' the other, the idea being that the first will be the true guinea pig, the second actually stands a chance...).

Both OLF OM's.
#1 = Ambrosia Maple
#2 = Waterfall Bubinga (yea, probably not the wisest choice for a 2nd... but... I'm goin for it)

I'm getting a bit ahead of myself, but, I know there's an answer/answers out there that I'm not finding by searching.

I've now shot and will be joining two AA Sitka tops. They're still in their "raw" form from LMI, so it's not wholly accurate yet, but the're right about the same size and one is noticeably heavier than the other.

So my question is this; given the choice of the two tops, one being heavier than the other, is there something there that would make you inclined to use one top over the other (lighter vs. heavier) on either of the above guitars (Amb. Maple vs. Bubinga)?

I know it's definitely not THAT simple to answer and that weight doesn't necessarily go hand in hand with stiffness, etc. But, taking into consideration that I'm a pure novice... Whaddya think?

Thanks in advance.

Timbo

Timbo: Is one top noticeably stiffer then the other? If they are approximately the same I would be inclined to put the lighter top on your second guitar. You will hopefully have less problems with that one and more chance of a better outcome. I hope you are not building the two guitars at the same time.Build one at a time,learn the processes on the first and proceed from there.Have fun in your adventure.
Tom

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A person who has never made a mistake has never made anything!!!

Are the tops you are comparing the exact same dimensions?

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Formerly known as Adaboy.......

Thanks for the input Tom!

I am building both "at the same time" so to speak, but the idea being that I go through a given process on one, then the other. Maybe better to think of it as having one "test" guitar to practice/learn a given procedure on before I can do it on the "real" guitar. I don't have any intention of doing things on both guitars simultaneously (i.e. bracing two tops at once. I'll brace one & finish that part, then brace the other... that sort of thing). If I find that I'm biting off more than I can chew, I'll just put the 2nd aside, and only work on the first.

At least as they sit now (just joined last night), the tops seem to be "about" the same stiffness. Granted, that's nothing more than me giving them a little flex with my hands. I don't have the facilities/equipment yet to do any sort of deflection tests.

So, Is the idea you're going for that; given the same stiffness, a lighter top is more _______??? (responsive/well rounded/balanced/will match bubinga better than Maple)????

Or, that It's just generally better to have a lighter/stiffer top for all guitars and, since I will probably make more mistakes on the first, it's saving the better top for what hopefully will be a better guitar?



No, they're not exactly the same size, but they're pretty darn close. And the weight is different enough that I'm confident that even at the same size, one would be heavier than the other (i.e. one is more dense than the other).

The best thing to do is to figure out their density.....

Start by sanding/planing off the saw marks - or if they are already sanded, go ahead and measure thickness with a micrometer....

Then, measure length and width - LxWxT = Volume.
Weight / Volume = Density.....

Density usually tracks with Modulus of Elasticity... MOE x (Thickness)^3 is proportional to Stiffness long grain - so knowing the density gets you in the ballpark....

Now... Are they really much different in density, or was one plate just 30% thicker than the other?
The trouble with rough cut plates is that they vary IMMENSELY in dimensions - so a plate that FEELS heavier and Stiffer may just be thicker and of less dense spruce.....

Ok.. SO you did check and found that one plate is actually quite a bit more DENSE than the other..... Likely it's also quite a bit harder at the same thickness.....

Best thing you can do is to use the more dense piece for the guitar you want to run heavier strings and intend to play harder.... Use the Less dense piece where you want to run lighter strings or you want to play more fingerstyle.... Hard, dense spruce can make a fine unamplified stage guitar where you plan to play it hard and loud.... like a Bluegrass dread....

Now... If one piece is like 50% less dense than the other - save it for a Classical guitar or something along those lines....

Thanks

John, That's a GREAT answer.... thank you!