Mandolin neck reset stats?

[clarksavage]

I am very curious. I've been playing my Martin guitar and engaged in a discussion about the Martin warranty and its coverage of "defects in materials and workmanship..." and I thought, my goodness, a neck reset for a guitar seems to be a fairly normal thing, every 30 years or so (need it or not :-) because of the stresses on the various parts of the guitar itself, not because of any "defects." But bless Martin, they cover that under warranty (I'm sure they build it into the price.)

Now, I have a 1926 Gibson A4 and the neck angle is just about right and its never been worked on. Is it the tailpiece that transfers a lot of the stresses to the bottom of the body and then there is just the downward pressure on the top (ah, the arch!) and the stresses pulling the neck are more equalized than for the guitar?

If this is about right, then my Octave Mandolin should do fairly well over time (I like the thing, I hope it lasts a long time) as it has an arched top (not carved, but arched just noticeably) and the tailpiece is attached at the bottom of the body, then the neck should hold its own with its carbon fiber reinforcement.

Just interested. Any comments welcome. I love this message board.

Clark

[mythicfish]

Short scale and (relatively) stout neck = less chiropractic care?

Curt

[Dave Cohen]

Movement in the neck itself is not the usual reason for a neck reset in a guitar. It is deformation in the upper bout of the guitar body under the influence of string tension that creates the need for a neck reset. The top plate wants to cave on the heel side of the bridge, and bulge out on the tail side of the bridge. It is possible for that to happen in your OM, though less likely and less pronounced. The narrowness of the OM body in the heel region and the orientation of the ribs in that location is in its' favor.

[Big Joe]

Neck resets are fairly rare in old Gibson mandolins. It is a combination of the materials, the structure, and the way they were built. In the older A and F4 pre truss rod era the necks were very thick and were quite stable. Rarely do they need a reset unless something has happened very bad to the mandolin. From the 20's and 30's the dovetail neck joint was very good and has resulted in very few resets. We see neck resets more common from the sixties through the mid nineties. During this era the dovetail neck joint was abandoned and a system of mortise and tenon joints were used. These give good wood contact but have not been as stable as the old dovetail joint. That is why Gibson went back to the dovetail neck joint in 99. We have had great success with the dovetail and it serves very well for the purpose it is intended.

Depending upon how a mandolin is built and the quality of the neck joint, one may never see a reset or one may see one very quickly. We reset the neck on a mandolin from a current builder (who will remain nameless) on a mandolin less than a year old THe only think holding the neck in was a sheetrock screw. While the mandolin was pretty to look at, the quality of the build was way substandard and we were appalled that a builder would sell a product like that for a good price. No, it is not one of the "better" builders on the cafe.

A mandolin is structered differently from a flat top guitar. That is part of the reason the neck joints last better. Second, the shorter neck gives a lot more stability. In a well build mandolin with a good neck joint one should not expect to see a need for a neck reset for a VERY long time....if ever.

[clarksavage]

Thanks Dave, that makes sense to me when I think about it.

Thanks, Big Joe, your explanation helps me a whole lot. My old A4 was handed to me for free after it floated around during the Agnes flood in 1972 inside its original case for a few days!!!!! I took it backpacking on the Appalachian Trail inside its original case. Nothing bad has happened, in fact, it is in very good shape. The case doesn't look too good, though. I guess that's what a case is for. Thanks to the Gibson guys in 1926! It still rings.

Clark

[Antlurz]

A simpler explanation, though you already see it, might be to take a 12 inch square piece of 1/4" plywood, and while holding it by the edges, push in the center with your thumbs. Not much is gonna happen. Take a 4X8 foot sheet of the same plywood supported at the ends and exert that same thumb pressure in the center, and you will get a very noticable bend in the board. That's more why guitars give up and mandolins don't.

Ron

[Paul Hostetter]

As a Martin warrantee guy, I can say that Martin will not reset a neck under warrantee, nor will they pay me to do it, unless it's a bolt-on. It used to be a terrible situation, but to be honest I think Martin finally figured out how to put a neck on right. Back through the 80s many Martins came direct from Nazareth needing resets (a cause of some discomfort between me, Martin and customers) but they've made some production refinements (including radiused top braces) that make me think most recent Martins, like many other quality factory instruments, may never need a reset. The results are not all in yet, but I have 90's Martins coming by from time to time and they're holding beautifully with their first setups. At best a trussrod adjustment.

The old Gibsons are a masterpiece of engineering.

[Rick Turner]

Tim Teel, of the Martin R&D team, told me that he thinks that the biggest issue is the overall stress on the guitar body that tends to flatten out the back arch as the leverage on the heel takes its toll over the years. That allows the neck block to rotate forward as the fingerboard presses down on the top. Then the lower bout top bellies behind the bridge and collapses a bit in front of the bridge. That can be either a net zero change on the action or you'll see the action go up.

Paul, when did Martin abandon hot hide glue? I wonder if there's a correlation there with neck resets. It may be that the Martins put together with Titebond will need more neck resets as the glue lines slowly shift with cold creep.

Martin's new warranty does protect them a bit better than it used to. They've been one of the best companies in the business with that, but I'd bet that paying for any kind of warranty work just erases the profit margin on that guitar. They can't stay in business covering what we now know is normal wear and tear.

[Paul Hostetter]

Martin switched to Titebond (I think they actually started with simple Elmer's) around 1965 or so. They were churning out guitars with awful necksets in the hide glue era and well into the Titebond era. What I saw at the end of the 90's was an entirely different approach to neck angle and saddle height that seemed to be in tandem with their move to more machined parts.

The hard part about "normal wear and tear" was that it was either owner abuse or an act of God, which is how they regarded a pulled neck and why they'd do nothing about it. Excuse me, but a brand-new guitar, right out of the box from Martin with the saddle all the way down on an already low bridge, has experienced no normal wear and tear - it's a defective guitar. They didn't see it that way, and the customer was simply screwed. I saw that happen time and again. At the time the most Martin would do was shave the bridge even further, but you had to pay shipping both ways. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/tounge.gif

I'm glad things have changed.

[acousticphd]

A question from an interested novice about this. If you look inside flattop guitars, you usually see a neckblock that is in flush contact with, and glued to, both the top and the back. In newer Martin guitars though, there is a gap between the neck block and the back - there is no contact there. Why is this? Is this somehow more resistant to forward neck block rotation, as described above? It would seem the opposite to me.

[sunburst]

My experience squares with most of what is written here.
Of the Gibson mandolins that I've re-set necks in, most were from the 60s with some variation of a mortise and tenon joint. One was a 30s F5 with a split head block.

Rick, I seldom see a glue joint fail in a Martin guitar neck joint (though it does happen occasionally). They almost always need re-sets because of the geometry of the guitar, whether from age or from questionable construction. (Two that I can remember the neck "falling" out of were a '40 D-28 and a '56 OOO-18, both from the hide glue days.)
Whether hide glue or plastic glue, I always seem to get the ones that only come out of the guitar after copious amounts of steam and sweat. When the joint is like that, I don't think the type of glue makes much difference.

[Bernie Daniel]

Big Joe: That is why Gibson went back to the dovetail neck joint in 99.

Joe, was that 1999 or was it 1989?

[Rick Turner]

The thing we all have to recognize is that hot hide glue in and of itself is no panacea. There were millions of guitars made with HHG that are just pieces of ####. They were cheap guitars, the glue had been cooking for days, they were sloppily put together...on and on and on. HHG must be used carefully and quickly to take advantage of it's good qualities, otherwise anyone is better off with Titebond. Glue joint must fit together properly unless you're going to use epoxy and fancy fixtures to establish proper geometry. So we can't pin a problem on one glue or another without looking at the total context.

What I'm interested in with this particular line of thought is whether well made guitars do better stuck together with HHG or Titebond. Let's assume that all other factors of fit and finish are equal. Now do the HHG instruments fare better than more creep-prone glues? Do they sound better?

In our own building of acoustic guitars here, we're using more and more HHG in those joints where I imagine it might matter more...top seams, top bracing, top to sides joint. I'm finding it no more trouble to work with than Titebond or my preferred LMI white glue other than turning on the glue pot.

Sorry for the thread creep, but that's what can happen here like this when something like neck resets comes up.

[Rick Turner]

Oh, a point about neck and end blocks...I don't know what Martin is doing on those these days, but it's not uncommon to bevel back the butt block of a guitar to match the glue line width of the kerfing so as not to interrupt a smooth and fairly splined glue line around the rim of the instrument. However, it would surprise me to see that on a Martin neck block where stability is probably paramount.

[Gibson A5]

Paul, my uncle brought me his 1990 Martin D-28 for a truss rod adjustment and said it needed it because of the high action. #It wasn't the truss rod that needed adjusting much (I did adjust it some), it needed a neck reset, which I didn't do,(it still has high, but not unplayable action). #He takes good care of his instruments and this one was no exception, it still looked in like new condition. #Just saying this to let you know all 90's didn't hold up as well as the ones you have seen.
Bill P.
Paul, sorry, I just reread your post and you said end of the 90's, so it's a different animal.

[Mario Proulx]

It's only the low-end plywood Martins that have the beveled blocks.....

Rick, it isn't scientific, but I'd noticed, years ago and before I began using Hot Hide Glue myself, that pre-60's Martins tended to hold up better, and that 70's and later had more neck angle issues. I also noticed that the tops' glue line was always nicer on the older ones, too, where the newer ones often showed a raised ridge. I didn't even know of the glue switch(which was mid '65, same time as a slew of other detail changes) at that time....