Weight of ebony neck lams

[bob]

I've seen some comments lately suggesting that a single ebony neck laminate adds as much as a pound to the weight of a bass. That didn't sound right to me, though there does seem to be more general agreement that ebony lams will noticeably increase the weight.
 
So I took a stab at estimating how much this would actually be. On my bass, the lams are 1/4 wide. The portion in the body is roughly 14 long and 1.5 deep, while the neck section is 1/2 deep and 31 long. So for a single laminate,
 
body portion = 14 x 1.5 x .25 = 5.25 cubic inches
neck portion = 31 x 0.5 x .25 = 3.875 ci
total volume = 9.125 ci = 149.53 cubic centimeters
 
As a sanity check, take a block of wood 9 x 1 x 1 (9 cu inches). Using your infinitely-thin saw blade, slice it lengthwise into four pieces 1/4 thick. Take one of those, slice it in half lengthwise, and you have enough to do 18 worth of neck. So you don't need even half of the original block to handle the neck portion, and you should be able to satisfy yourself that the body portion can be handled by a little over half of the original. It's really not very much wood.
 
CC's are a little easier to work with, so call it 150 cc per lam, or 450 cc for a set of three.
 
Ebony has a specific gravity of .96, weight of 60 lbs/cubic foot.
Maple has a specific gravity of .71, weight of 44 lbs/cubic foot.
 
(You see slightly different numbers sometimes, but these are fairly typical - if anything, I think I've seen higher values for maple.)
 
A single ebony laminate should therefore weigh about 144 grams, a little less than one third of a pound. Three such lams would still total just under a pound.
 
Given a weight ratio of 44/60, the difference from substituting three ebony lams for comparable volume of maple is one quarter of a pound.
 
One quarter of a pound, if all three are ebony. That's assuming you were replacing maple; if you were replacing purpleheart, the increase would be less than half as much, since purpleheart lies a bit more than midway between maple and ebony in terms of weight.
 
Perhaps my math is wrong, which is why I mostly listed my assumptions and results, so you can work it out yourself if you care. Obviously, some laminates may be wider or narrower, but also keep in mind that any not in the center will be less thick (deep). Another interesting factor is that depending on where they are placed, a large chunk may be routed out to make space for the truss rods - depending on whether this falls in the heavier or lighter laminates, the difference will vary somewhat.
 
Still, unless I'm mistaken, concerns about the additional weight of ebony laminates appear to be grossly inflated. It would be interesting if someone were to either verify or correct me on this.
-Bob

[tubeperson]

If one can afford it, the ebony lams are well worth it.  You could always do crunches at the bench to beef up.  The ultimate sound is worth it!!!!!!!

[dwmark]

I'd like Mica or Susan to weigh in on this one.  I've also been advised to go with two ebony and one purpleheart, to save weight without giving up much in sound, and have to believe that the experts know.  But I follow Bob's analysis.
 
By the way, pun intended.
 
dw

[foth]

Bob  
Excellent job, as always, presenting the science of Alembics.
Is there such a thing as psychosomatic weight?  After working 15-20 hours every weekend with my four projects, I always feel on Monday that my 11 lb. bass must really be a 33 lb. bass!
Paul

[the_8_string_king]

Just for the record, I have a confession to make.  I've made an epistemological error here -which I do pretty rarely- recently.
 
I did indeed recently say that Ebony neck laminates weigh a pound per lam -or some such thing.  But I do not know this to be true.  I recall seeing the claim made on AT LEAST one other thread -I BELIEVE more than one thread- that this was so; and I have an IMPRESSION of the recollection that I believed/regarded the claim as valid... based on my perceived credibility of who said it.  I took it as an epistemological short cut.  (I took that person's word for it.)  But the fact is, I don't know if it's true, and one way or the other, it's an epistemological/logical error.  I should have qualified the statement with a disclaimer.  I can't recall who said it, and regardless, I don't know it it's true.
 
So I apologize to any who may have taken MY claim as an epistemological short cut.
 
And at this point, I'm curious to hear what the TRUTH is from any who KNOW.
 
What's the truth here, knowledgable ones?
 
P.S. It seems logical to have a frame of reference... that is, to have the relative weights per laminate of Rock Maple, Purpleheart, and Ebony, so that one can appreciate THE relative difference in weight resulting from substituting Ebony for Purpleheart vs. Rock Maple.
 
(Message edited by the 8 string king on February 02, 2007)

[bsee]

I believe that I wrote that based upon what Mica told me.  The topic arose between she and I when I was wondering why my new SC Deluxe weighed in around 11.5 pounds, just over two pounds heavier than another SC bass that I own.  The basses have similar neck dimensions and the same body core wood.  The differences are cocobolo top/back, one ebony neck laminate, and gold-plated brass backplate on the heavier bass vs. a vermillion top and plastic backplate on the lighter one.  Additionally, the heavier bass was supposed to have the core hollowed as much as possible to control weight.  I can't be sure, but I doubt the same was true of the lighter one.  
 
I was wondering if maybe they forgot to hollow the body core or something so we tried to figure out where the extra weight was hiding.  The brass backplate was significant and the guess was that the ebony was another important piece.
 
-Bob

[southpaw]

Sorry, I got to highjack this thread for minute;
8 string king, no problem on ebony lam weight, we'll get the true weight soon but you got me with the word epistemological.  I haven't seen that word in years, you had me running for the dictionary. Could you define it's use for me in your previous post? Time for some schoolin', then we'll return to the original post. Thanks.

[bob]

Mark, no need to feel defensive. I was also pretty sure I'd seen at least one other person mention it here, and had a feeling that the concept also had some backing from people at Alembic.
 
I just have this problem with bad science, and more importantly would hate for someone to pass up on laminates they wanted for tone, on a (probably) mistaken assumption about the weight factor. Cost, of course, is a completely different matter.
 
And hey, I could be wrong.
-Bob

[the_8_string_king]

Hey, Hey, Hey, no defensiveness here guys, it's all cool!  I'm just owning up to an error.  It's the right thing to do when you make one... for me, it's the only thing.
 
Paul, Epistemology, along with Metaphysics and Ethics is one of the 3 primary/fundamental branches of Philosophy.  Philosophy, as a discipline, deals fundamentally with 3 basic concepts: reality, knowledge, and purpose.  Metaphysics deals with reality; Ethics deals with purpose; and Epistemology deals with knowledge.
 
Specifically, Epistemology is the theory/science/method of knowledge.  As a discipline (or branch of a discipline) Epistemology deals with/formulates answers/knowledge about the nature, limits, reliability, and methods of knowledge -and related issues.
 
Epistemology deals with such concepts as true & false, knowledge (and belief, and the difference between the two), certainty, proof, error, logic, language & symbols, concepts, etc.
 
One of the most common/basic epistemological errors people make is to present as fact something which is an unconfirmed belief.  This was the error I made... well, I think I did.  I actually haven't gone back and checked which I guess I'll do next, but I think I just said Ebony neck laminates weight a pound, and since I don't actually know this is true, I should have said a disclaimer of some sort, like my understanding is that... etc.
 
Anyway, that's what Epistemology means.

[dfung60]

bob
 
I agree with your analysis, however, I think there is one small flaw - your headstock is probably only 1/2 thick, but the rest of your neck (even excluding the significant fingerboard thickness) is considerably thicker than that.  On a bass that I had nearby, I think the laminate portion of the neck is probably more like 3/4.  So, increase your volume calculation by 50% and it'll be slightly more accurate, but your conclusion stands.  
 
If ebony is replacing purpleheart in the stringers, then you might see another pound of weight in the finished instrument (10% !!), but probably not more than that.  
 
 
bsee, I think there are enough differences between basses that the 2lbs difference isn't that surprising.  You gain a couple of ounces from the neck lam, more ounces from the metal back plate.  
 
But the big difference is the tops - the cocobolo (0.82 specific gravity) is denser than vermillion (0.75), and there's quite a lot of wood there.  If the body plates are roughly 14 x 6 x 0.25 each and there are 4 of them, then you're talking about 84 cubic inches of cocobolo.  Even if the core was hollowed out, the additional cavity would only be about the size of the control cavity and in much less dense wood.  Even at just 10% additional weight compared to vermillion, I would suspect that at least 10-12 oz of the difference is the cocobolo.
 
David Fung

[olieoliver]

I've reread this thread 3 times now and as John Cleese would say My Brain 'urts!

[bob]

David, I measured again and you're right about the neck being a little thicker. Still, on mine (which is a slightly thicker sterling shape) 5/8 would be generous as an average thickness, excluding the fingerboard of course.
 
Running that through the calculations gives a 10% increase in volume, to 10.09 cubic inches per lam, or 30.28 ci (496 cc) for three. Replacing three purpleheart with ebony would add about 50 grams, less than 2 ounces.
-Bob

[inthelows]

I'm with you Olie!
Mark, even if you did make a mistake, it was marvelous! (as Billy Crystal would say.)
NLP

[southpaw]

Hey Mark, thanks for the info, quite thoughtful.  I only had one philosphy class in college many years ago. Don't worry about misquoting around here, as you know this is fun place with good people who help each other, no finger pointing, just people enjoying life & Alembics.  
The hijack is over, back to our original thread.
Thanks everyone.

[hifiguy]

Hi Olie
 
It was actually Michael Palin who said My brain hurts!!  John Cleese was the doctor in the sketch, identically dressed as a Gumby, who provided the punch line:  My brain hurts too!
 
Paul
 
 
 
I will not be pushed, filed, stamped, indexed, briefed, debriefed or numbered.  My life is my own; I am a free man.
 
- Patrick McGoohan (The Prisoner)
 
Edited for bad typing
 
(Message edited by hifiguy on February 03, 2007)