Before going to the fix, let's look at the problem and its cause.
Problem (observation):
You have two lamination seams separating. They seem to be separating towards the back of the neck, and still together at the front. One of the seams splits by a tuner screw, comes back together, and splits again at the volute. The other seam is split in the vicinity of a tuner screw, and then all the way up to the top of the headstock.
It is assumed that when the bass was manufactured/purchased, this was not the case.
Causation (analysis):
For them to separate, there must be two coexisting factors:
a. A force causing tension at the seam
b. Insufficient opposition to this force by the glue joint.
Let's look more closely at some possible contributors to these two conditions. (letters reference the previous paragraphs.)
a1. The force may be caused by the tuner screws at the seams, combined with insufficient pre-drilling. However, split-together-split separation of the outer seam would seem to counter-indicate this as a sole cause.
a2. It could be due to warping/twisting of the wood, perhaps made worse by a1.
b1. The joint could be improperly formed (boards not flat, smooth, and parallel).
b2. The joint could have insufficient glue.
a1 is probably contributing. The open-closed-open seam mentioned in a1 seems to imply that a2 would be at least partially to blame. b1 and b2 might be contributors, also.
What can we do to test? Measure the response to removing the screws. (
more observation: ) Take the strings off; measure the gap separation by inserting a business card as far as possible at specific places, and drawing a line on the card where it emerges from the crack. Then remove the two screws, and check again. It may close up partially, completely, or not at all. This maybe be important to know when figuring a course of action. Why?
(analysis) Because, if twisting of the wood caused the seams to separate, then even if you glue the seams closed under clamping pressure, the tension will be re-introduced and sealed back in the joint, and will stress the new glue line. And at that point, you are hoping that the stress is not so great that it will either re-split the new glue, or split the wood.
Fix (action):
Here are some possibilities.
1. You can go back to Ibanez, and ask for a new new bass, if it is not discontinued. This is my suggestion for a first course of action - even if it an older bass. It can't hurt to ask. A person presenting a logical case in a straightforward, unemotional manner will hopefully at least be listened to.
2. You can re-glue, with clamps. This will work fine and look good, unless embedded tension re-splits the joints. If a1 and b2 were the only reasons for the failure, and you re-pre-drill the screws, this could be just fine.
3. You can re-glue, without clamps or with partial clamping, using gap-filling glue. This will not be as attractive, but may be less prone to re-split.
That's what I've got, though certainly there are other possibilities I've missed.
BTW in my experience with CA specs, while they do bond with gaps, the strength goes down as the gap increases. Some CA's are more sensitive to this than others, but all I've run into so far have this characteristic.
