NECK RESET - ever necessary on a mandolin?

[scgc.om]

"A guitar either: A) needs a neck reset now, or B) will need one later."

But is the changing of neck angle an inevitability, as it is with a guitar? Will any/every mandolin eventually need a neck reset?

Thanks for your thoughts.

[pickinNgrinnin]

Yes, probably true with a Guitar. May not be the case with a Mandolin. Obviously there are lots of old Gibson's out there that are still in original condition and play perfectly. They seem to have passed the test of time. My Yellowstone may eventually need a neck reset but I doubt it will happen in my lifetime.

[BigJoe]

The Loar era mandolins rarely, if ever, need a neck set. The others may in time. We see several a week that need a neck set. The worst ones are the bolt neck mandolins. A good dovetail joint closely fit is the best protection for the instrument.

[pickinNgrinnin]

[QUOTE]The others may in time.

80 - 90 years is a pretty good track record Big Joe!

When you mention the (worst ones) bolt neck Mandolins needing neck re-sets, are you referring to the Montana made Gibsons/Flatirons?

[Big Joe]

Yes, along with others. There are some others that we see pretty often, but it really does not matter. Many of the mandolins in the hands of players are throw aways so we don't have to worry about them. Most of the pac rim mandolins are not really able to deal with. They are meant to be used while they last, then pitch them into a dumpster. If it were a banjo, it would be perfect pitch! http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif .

[pickinNgrinnin]

Big Joe-

When you do a neck reset on a Montana Gibson or Flatiron, is there any way to convert the neck joint to a dovetail without the bolts? Or do you just put it back together the way it was built? Is the neck joint on the Montana Gibson's/Flatirons more mortise and tenon type than dovetail? Perhaps dumb questions here but now I'm curious.

[steadypluckinaway]

where is the bolt located? This too may be a dumb question, but my Flatiron 1N has a sticker that is on the neck block and you can just see it if you look through the soundhole. Is it covering a bolt? Wish it had a truss rod. It's getting out of hand, and I don't know if it is worth the cost of repair.:(

[racuda]

The worst ones are the bolt neck mandolins.
Isn't a bolt on neck supposed to make the neck removal easier, and a reset therefore easier and cheaper?

[BigJoe]

The bolt on neck is not easier on a mandolin and that is not its purpose. The reason most use a bolt on neck is it is easier and cheaper than building a good dovetail joint. Not everyone can do that....even with good woodworking skills and bolting it in place is easier. Fixing them is as difficult, if not more, than a dovetail. Remember, mandolins are different from guitars.

[diamond ace]

how about the new webers? are they bolt on necks? and if so have you seen any problems with them?

[pickinNgrinnin]

The Weber's, both new and old have bolt on necks - as did the Montana Flatirons and Gibsons.

I suspect Bruce Weber could make a good dovetail joint. With all of the CNC work that is used in production Mandolins, I have to wonder if the bolt on neck is really that much faster to produce. I assume the bolt on neck still needs to be fitted to the body and the neck angle has to be checked and adjusted.

It seems to be a difference in design philosophies. I don't think having a dovetail neck joint will guarantee you will never need a neck reset. Tension, time, humidity changes, etc. all conspire against the Mandolin. Just play em and enjoy em. The good ones will probably outlive us all - bolt or no bolt. #http://www.mandolincafe.net/iB_html/non-cgi/emoticons/mandosmiley.gif

[FrankenMouse]

Of course, a dovetail joint is no guarantee that a mandolin will never need a neck reset. My 1925 Martin A-Style is about due for one. (Anyone know a good luthier in Vancouver? I know... different thread...)

The neck on my 1914 Gibson is great though!

Maybe I should call this post, "A Tale of Two Dovetails".

[futrconslr]

So who besides big G uses a dove tail?

[MANNDOLINS]

I still say..who needs a neck joint?

[Michael Lewis]

Some considerations concerning neck joints: properly fitted dovetail joints don't fail, bolted neck joints can fail. Aside from that, the body structure can deform, thereby requiring a neck re set. If a mandolin with a dovetail joint is properly planned and the plates properly carved it should never need a neck re set. Top plates that are carved too thin or improperly arched are more prone to failure.

You can't make a bolt on neck joint into a dovetail joint, but you can carefully shim the bolt on tennon and glue it firmly in place. No one would want to try to remove it again though.

[Mando Medic]

Let's not forget the 60's and 70's Gibsons as they too are frequent candidates for neck resets. I've done a few. Kenc

[Mike Buesseler]

Ok, I'm not a luthier, but I am able to understand some basic mechanics. #ANY kind of joint, when new, should be able to work, right? #A joint that later leads to a neck reset must be because the joint came loose. #Right or wrong? #So, what's hard about retightening a bolt-on neck? #

Please be patient with my thickheaded, amateur ignorance.... http://www.mandolincafe.net/iB_html/non-cgi/emoticons/rock.gif

[Michael Lewis]

When a bolt starts to pull out of wood just retightening may not be a good idea. The area needs to be stabilized before tightening. Sometimes all it takes is to apply some super glue to the wood threads to strengthen them before re installing the insert, but to get to it you need to remove the neck, and that requires that the fingerboard be removed from the support, and the neck lifted out. Don't mess up the finish or the binding. Then it all has to go back together properly. It is a bit of a job, not just a quick fix.

[Dave Cohen]

(1) If the bolt is tightened into a captured barrel nut, as in Cumpiano's guitar neck joint, the problem which Michael alluded to is not there.

(2) Mandolins, bolt or no, are currently finished with the neck assembled to the body. With guitars, the body and neck are finished separately, then assembled together. Thus, re-setting the neck on guitars does not involve breaking the finish at the neck/body joint, whereas re-setting the neck on mandolins currently does involve breaking the finish at the joint.

The key to making any hardware joint is the engineering. A well-engineered hardware joint should be as good as a dovetail joint, with the added advantage of being easier to remove and re-assemble.

[Mike Buesseler]

The key to making any hardware joint is the engineering. #A well-engineered hardware joint should be as good as a dovetail joint, with the added advantage of being easier to remove and re-assemble.

This would seem to be the main point, regarding the structural strength differences between dovetail vs bolt-on necks, then, am I correct? # All other things being equal (which, I know, they hardly ever are) well made joints of either type would do just fine, perhaps giving an edge to bolt-on as far as ease of repair goes.

I do appreciate the finish issues. #I know this is no small thing. # But, especially on an older mandolin, the simpler process of a bolt-on neck might be easier to do than a dovetail.

I had a Franklin guitar once, made by Nick Kukich. #I'm sure a few luthiers have heard of him. #One of his special "features" was some kind of bolt-on neck, which was supposed to make the eventual neckset SO much easier. #Michael, yes, I read your comments about the finish problems of mandolins vs guitars. #I'm just trying to get this straight. #

Michael claims that a dovetail will never fail. I believe this. #So, why do some good luthiers use the bolt-on?
(I'm not looking to cast aspersions on any builders. #I just like to know the why of things...)

[Kelly_guy]

As I mentioned when I first got here, my early 70's Gibson A-12 (lumpy) is in the shop for the 2nd neck reset. Sounds like they used a really awful design during that period for the neck attachment. So does my lumpy have a bolt-on neck or a mortise and tenon joint? Or both?

[Michael Lewis]

Kelly guy, I'm not sure about your Lumpy, but I re set the neck of a '77 F5 that was just a straight mortise and tenon. It was left in a car in the summer, the glue got soft and the string tension pulled the neck up pretty good. The glue seemed to be similar to hot melt glue, like used in glue guns, as it was quite flexible even when cold. There is plenty of surface area in that joint to hold the tension if it is fitted snugly (shims if necessary)and the glue is good.

I agree with Dave Cohen concerning the engineering of bolt on joints, the existing problem is the bolt on necks with threaded inserts that get stressed and pull out a bit. My first mandolins had bolt on joints, but I have long since switched to dovetails. One of my bolt on joints loosened, none of the dovetails have, yet. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/cool.gif

[Dave Cohen]

Michael, I never liked threaded inserts. I tried one, with unacceptable results. On guitars, I make my own captured barrel nut by drilling and tapping a section of 3/8" rod. I drill vertically through the heel to trap the nut. The drilling requires about as much precision as a traditional dovetail joint, but the results are good. I wouldn't consider going back to a dovetail on guitars.

I haven't tried a hardware joint on mandolins yet because of the finish issue. I am still thinking about it though, and hope to get to it one of these days.

[BigJoe]

The Gibsons from the 60's till they went to Flatiron used whatever method the current builder could figure to hold the neck and body together and they can be a pain to reset...but not impossible. The bolt in neck is NOT easier to reset for a number of reasons. All too often the inserts will pull out of the neck and either cannot be reused or are difficult to repair.

A good many bolt necks will fail in a lesser number or years than one would expect. It is not uncommon to see mandolins from the eighties and early nineties with bolt necks need reset. The tension on the neck of a mandolin is much greater than on a guitar and that affects the joint pretty seriously.

One last comment, some guitar makers do finish the guitar after the neck is installed so the finish is a factor in neck resets on many guitars too.

A good dovetail joint is still the best at distributing the stress without causing the neck joint to pull loose.

[Nick Triesch]

Sorry Joe. I think you use this site to belittle the smaller makers when you get the chance. This is about the neck joint system. I really think you are not playing fair. I have so much more respect to shops like Weber who never and I mean never put down Gibson products on this web site. When you say things like the Gibson dovetail system is the best and the you have seen many bolt on necks fail.... Well it's ok. Just look at how well Weber is doing and the others like Breedlove and Collings. There are a lot of things the other makers could say about your mandolins but they don't. I think they have to much class for that. Nick

[Dave Cohen]

Joe, you glossed over a couple of important points. I agree that threaded inserts can pull out. That is what happened to me on my one miserable attempt with a threaded insert. But I never repeated that experiment. I stated above that I use a barrel nut captured in the heel of the guitar neck. That nut will NEVER come out, unless the entire heel fractures - not likely. Before you gloss over that again, you owe it to yourself to look at bill Cumpiano's website, with his description of his new(est) neck joint.

Second, maybe some guitarmakers do finish their instruments with the necks assembled to the bodies, but I don't know who they are. Martin certainly doesn't; Taylor certainly doesn't; nor do Collings or Santa Cruz or Huss & Dalton. And most important to me, I don't finish guitars with the neck assembled to the body. So the finish is not a factor in neck resets for me.

[BigJoe]

Nick...I have nothing but respect for other builders and have not said anything against any of them. My comments are not directed toward them or any small builder. Remember, Gibson and Flatiron also used a bolt in neck for a good while. There is a reason we have changed. My opinion is not designed to put anyone down and any attempt to make it such is just a forced effort. When it comes to repair or construction there are varying opinions...just like anything else. For me to say any less that what I believe to be true...by many years experience and having seen so many variations...would be wrong. One does not have to agree with me. One does not have to believe me, but I still reserve the right to express my opinion. Besides, if we felt there was a neck joint system superior or equal to what we do, we would be using it. We have not. My comments are not a put down, just our belief. If you like the bolt neck, go for it. You may feel different in fifteen years when it needs repair. If the current mandolin bolt neck makers have not had problems, it is because they have not been making them long enough to have a history to stand on. Collings does not use a bolt neck in the mandolin. For those that do, there is a difference in price. Whether that value will hold in time is yet to be seen. In the ones we've seen so far, the failure rate is pretty high.

That does not mean they are not repairable, just that they fail more often than a dovetail system. It's amazing that Loars have lasted eighty years. No bolt necks have been around long enough to see what their track record is. But, in mandolins and guitars, they do not seem to fair as well overall as a good dovetail. Maybe one of the current builders can change that, but history has not shown that to be true yet. Let's discuss this again in another twenty years.

[BigJoe]

Hey dave...my comments for bolt necks are more reserved to mandolins. The bolts in those necks have a tendency to pull out more than on guitars because of the higher stress on the mandolins. There are some great makers with bolt necks in guitars but history has not yet shown them to be superior to dovetail joints. Mandolins and guitars are similar, but quite different and therefore what may work on one may not work on the other. Like I said in my previous post. Let's see where we are in another twenty years and see how each holds up. In the meantime, I refuse to have a bolt neck mandolin but one of my favorite guitars is a bolt neck...much to my surprise http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif .

[Michael Lewis]

Aww c'mon you guys, don't be so hard on Big Joe. He's one of the good guys, and is here to be helpful. I know he has gone a long way to remain civil at some of the remarks thrown his way. If we can all get together we'll all be on the same side. WE're not children here, let's not act like 'em. http://www.mandolincafe.net/iB_html/non-cgi/emoticons/wink.gif

[Dave Cohen]

Joe, I just did the string tension calculations for a mandolin, 13.875" scale, w/ J74 strings and a Dreadnought guitar, 25.4" scale, w/ medium guage strings. The results:

guitar: approx 96 kg total tension
mandolin: 87.4 kg tension.

[Dave Cohen]

Joe, I just did the string tension calculations for a mandolin, 13.875" scale, w/ J74 strings and a Dreadnought guitar, 25.4" scale, w/ medium guage strings. The results:

guitar: approx 96 kg total tension
mandolin: 87.4 kg tension.

[VernBrekke]

This topic seems to come up periodically and we hope that it will be helpful to add some additional information, about our instruments, to the discussion. In general, there have been three types of neck joints used for instrument construction: the dovetail, the mortise and tenon and the bolt-on. The reinforced mortise and tenon neck joint that we use has not really been discussed but is often, incorrectly, associated with bolt-on necks or other types of mortise and tenon joints.

The dovetail and the mortise and tenon are fitted and glued joints when used on mandolins. They maximize surface contact between the neck and the body of the instrument and they are very stable joints, when done well. After the glue dries, they are not adjustable or easily replaced. True bolt-on necks are very different. They are not designed to be glued. A bolt-on neck may be removed or replaced by simply taking out the bolts and lifting the neck off.

When we started Sound To Earth, Ltd. we were not locked into any specific tradition. We could choose or invent whatever design elements we felt were best for our instruments. Most of us have worked with other neck joints in the past (I was responsible for adjusting the equipment that cut guitar dovetails at a previous job) and we prefer the structural strength and simplicity of the reinforced mortise and tenon joint that we designed and use. Our neck joint gives our instruments a tight, strong, and stable fit at the heel and body with very consistent neck angles on all three relevant planes.

The tenon is a simple rectangle the height of our ribs and extension block (1 3/4 inches tall), nearly an inch long and a 1/2 inch thick. The matching mortise is also a simple rectangle. It has very large wood-to-wood contact areas and we get a strong glued joint, on six matching surfaces (four sides of the tendon and two wings that transition the neck to the body), that has its greatest structural strength perpendicular to the force of the strings. The large height and length of the tenon also gives the joint good resistance to lateral and twisting forces. The screws, that we use, go through the headblock and into barrel nut inserts in the tenon. The style of insert and the way that they are placed is unique to our “WEBER” instruments. They clamp the neck against the body until the glue dries and give mechanical support to the joint after the glue has set. Since two of the three relevant neck angles are determined by two vertical cuts, perpendicular to the body and parallel to the center-line of the instrument, we really only have to focus our adjustments on the primary neck angle. We use two screws so that we can do fairly minute adjustments to that neck angle before the glue dries. All of the design parameters of our mandolin body are dependent on these neck angles. The top graduations; brace dimensions; and bridge height are optimized to our specific angle. If that angle varies from our intended specifications the tonal qualities of our instruments will be changed and we don’t like that. The mortise and tendon joint is ideal for keeping these angles consistent, from instrument to instrument, and that consistency is a primary reason that we use this style of joint. We also like the very tight fit that we get from the heel of the neck to the body of the instrument.

We do not believe that the mass or the weight of the screws will have any affect on the tone or balance of our instruments. The screws and inserts weigh less than 1/2 ounce. Our necks (peghead, veneer, tuners and fretboard) can vary in weight as much as 3/4 of an ounce - with a typical weight being 16 ounces. Wood is wood and the weight and density of it changes from piece to piece. With the average weight of our mandolins being 32 ounces, the screws represent an imperceptible fraction of the weight of the instrument. They are also located very near the actual center of balance of the instrument so their effect on the instruments balance is even further reduced. The shape of the neck and peghead; the type of tuners, and the style of tailpiece will have a noticeable effect on the balance and weight of the instrument. Our screws will not.

I apologize for the advertising quality of this post but we feel that our reinforced mortise and tenon joint has many inherent advantages for our instruments and our customers and that it should not be misunderstood or confused with other neck joints.

Thanks,


Vern Brekke,
Sound To Earth, Ltd.

[mrt10x]

Vern,

so if I read the post correctly, you and Bruce had the option of using a dovetail joint and chose instead to use the described mortise and tenon joint. #I would assume that CNC'ing a dove tail joint would be as simple or even more simple than the described mortise and tenon joint, so the "its cheaper and easier to produce a Weber neck joint" argument probable doesnt hold much water. Any chance we could see a picture of the Weber joint? or is that classified industry secrets? http://www.mandolincafe.net/iB_html/non-cgi/emoticons/smile.gif

[Bob DeVellis]

What a great, informative thread. Just on this page,we have Michael Lewis, Dave Cohen, Joe Vest, and Vern Brekke discussing the virtues of different neck joints. People pay money for information this good, and we here at the Cafe get it for free.

[Michael Lewis]

Vern Brekke, thanks for the information concerning your neck joint. I have never had a Weber neck joint apart, and it sounds as though I probably won't have a reason to ever see one unless I visit your factory.

Actually, it is fairly rare to see a mandolin that needs a re set. Flat top guitars on the other hand . . . . . . http://www.mandolincafe.net/iB_html/non-cgi/emoticons/wink.gif