A5 headstock crack

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I recently bought an A9 (MC classifieds) and after cleaning it up and restringing noticed small cracks at the bottom of headstock where the side pieces of wood are joined to the main center piece. I emailed the seller asking if he ever had someone look at the cracks and he said he never even saw them. Under bright light and magnification it looks as though they are filled with varnish (whatever finish used). Then while scanning the MC classifieds yesterday I saw a mandolin for sale with similar cracks. Is this common in A headstocks?

[barry]

It just looks like the finish shrunk into the headstock wings. Should be of no concern.

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That's what I was hoping! Thanks

[sunburst]

In both pictures the tuner plates screws line right up with the peghead "ear" glue joints. That is not ideal, and the wedging action of the screws can separate the glue joints. Either that has happened or the glue joints were pretty poor, or the grain direction is significantly different between the neck and the ears, or the wood was too wet when the neck was made, or some combination of those things.
The worst that can happen is: the glue joint fails and has to be re-glued. The best that can happen is...nothing.

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I was hoping you would respond sir! The thing is, the treble side crack falls right on the screw position(where the two pieces of wood join), but the bass side crack is off to the right of the screw position but it is where the two pieces of wood join as well, so I'm thinking that maybe both cracks were there from the get go! The thing that got my attention was that the Kentucky 'joint/cracks' were the same configuration as my A9 cracks!

[mirwa]

In both pictures the tuner plates screws line right up with the peghead "ear" glue joints. That is not ideal, and the wedging action of the screws can separate the glue joints.

Yep, not the best design.

[HoGo]

On the left picture I see the joint moved slightly and the finish didn't crack, just got stretched a bit, that's why you see it as valley.
On the right I think I can see some superglue in the cracks. Perhaps they were more severe and needed fixing.
John is right about reasons why this happens. Basicly it's diferent rate of expansion of the pieces - the central part has wood fibers going at an angle (follows neck shaft) but in the ears it typically goes right along the pieces. If humidity or temperature changes too much they expand in different rate and sometimes the joint just slips (and finish may or may not crack at the line) but it stil holds, sometimes the joints open slightly at the ends (the badly posoitioned screw can help it). The worst cases arise when high temperature hits high humidity for longer period of time (tropics), the glue softens and the central part expands more than ears causing the ears to warp and open joints at the ends.

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Thank you!

[derbex]

My Flatiron has a rather worse form of this. A luthier has managed to get a little glue in there to stabilise things, but it's not pretty.

[Tom Haywood]

Just to be clear for the OP, these are not cracks in the headstock. These are slight separations in the joints between the main headstock piece and the "ears" which make it wider. It's not all that likely that these joints will fail, and it should be an easy repair if they ever do. I wouldn't consider what you have here to be a defect, as I've seen similar in very old mandolins and they are still intact. It does make me wonder, however, why a company would design their headstock to have tuner screws seated in a glued joint.

[sunburst]

It does make me wonder, however, why a company would design their headstock to have tuner screws seated in a glued joint.

I don't think the company, or anyone else for that matter, designed the head stock to have the screws in the glue joint. Instead, I believe it was left to chance and the screws just ended up there.
It makes sense to use available wood for necks and glue the ears to whatever width that wood turns out to be, and by chance the screws can end up in the glue joint.

That's something I've learned over the years: leave as little as possible to chance. We can get away with it for years, not even knowing that there is a potential problem until the problem shows up. Something just happens to line up or come out badly and we find a new potential problem to avoid.

[Tom Haywood]

Yeah, that was a little bit of tongue in cheek to say that it is not hard to design and build a head stock that completely avoids this problem AND looks traditional. I've seen enough old mandolins that had cracked head stocks related to the inherent weakness of this joint with holes in and around it to know that it can be a problem. But in the vast majority of cases it is not a problem.

[Jeff Mando]

Actually it is very easy to design and build a headstock that avoids this problem -- you just use a wider piece of wood, so that the adding of "wings" is not necessary.....

One of my pet peeves is how makers try to save a nickel by going cheap. Same with scarf joints on cheaper brands. On a $5000 mandolin the wood cost saving can't be more than $20-30 bucks! What am I missing? Same with electric guitars -- they put a dime-sized pot that probably costs three cents, when they could use a USA pot that probably costs less than a dollar when bought in bulk......................................the "logic" escapes me! Ouch. Rant over.

[sunburst]

On a $5000 mandolin the wood cost saving can't be more than $20-30 bucks! What am I missing?

Production.
When a company is making thousands of instruments per year wood savings really add up. Also, supplies are more limited than they used to be. Martin (for one) now has trouble finding mahogany pieces big enough for one piece necks without ears, as they have traditionally used. Shipping adds up quickly too. Buying bigger wood and wasting more of it (by making one piece necks) costs the company too much money. As one after another wood species traditionally used in lutherie goes on endangered lists, using wood less wastefully is more and more important.
Using peghead ears causes no loss in quality if the wood is chosen well and the joint is done well. Sometimes, since the ear joint is not structurally important, builders sort of punt, don't choose the wood well and don't execute the joint well. When well done, ears can be nearly undetectable.

[peter.coombe]

Actually it is very easy to design and build a headstock that avoids this problem -- you just use a wider piece of wood, so that the adding of "wings" is not necessary.....

That is all well and good in theory, but you need to have the wider piece of wood in the first place. Maybe it is different in the USA, but I have nearly always used wings on the headstock because it is very rare to get neck wood wide and deep enough to make a one piece mandolin neck. About the only one piece necks I have made have been from Tasmanian Myrtle which can be a very large tree, but nowadays virtually impossible to find pieces big enough for a one piece neck. On guitars I have Mahogany neck wood wide enough not to have to use wings, but then the heel needs to be stacked. It is not a matter of cost, but what is available. The neck wing joints are not joints that you need to worry about. They rarely fail if executed properly and are easy to fix if they do fail. My failure rate is at 0% as far as I know.

[lenf12]

It may have been viewed as a benefit at the time to use the joint line as a point of reference for locating the screws for the tuners. Perhaps it was not seen as a problem at all. Points of view change over time...

Len B.
Clearwater, FL

[derbex]

For reference here are the cracks on my Flatiron

[Timbofood]

As the fault lies on a joint isn't this technically a "separation" which, in theory is not a major issue but, should still be monitored closely.
Just one mans opinion.

[bernabe]

For reference here are the cracks on my Flatiron

I've always bought, cut, or laminated neck blanks to be 2" or just under which isn't wide enough to avoid ears however avoids the screws from even accidentally falling on or outside the joint line. The A9 and the above Flatiron neck stock is far narrower than that for rea$on$ already mentioned. Ive yet to see a tone wood dealer offer neck blanks that aren't around the 2" wide mark and suppose there's a good reason for that.