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Hey guys,

I have a D-18 that came in with a loose neck joint. It is showing a slight gap at the heel and the gap can be opened and closed when applying slight pressure to the neck. I'm assuming the is a loose dovetail that just needs to be reguled, but I'm wondering what causes a neck joint like this to become loose? Dryness was my first though, although the guitar is not showing any of the regular symptoms associated with dryness. As a side note, the stamp on the neck block says CUSTOM with #1356138.

Interested to hear any thoughts from you repairs guys, especially those who work on Martins regularly.

Josh

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Josh House

Canadian Luthier Supply
http://www.canadianluthiersupply.com
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House Guitars - Custom Built Acoustic Instruments.
http://www.houseguitars.com

Most likely it was loose to begin with, but the glue held it up til now. Relatively easy to remove neck and shim the dovetail to get the actual joint to fit.

You have to pull it. Seeing the inside will most likely tell the story. A properly fit joint can be strung up w/ no glue and hold tight. Dryness is not a likely cause of the joint failing. Poor fit is.
You will probably need to remove any existing shims, glue on new ones, and fit the joint w/ chalk or carbon paper.
When sliding the neck down into the Dovetail, the very last bit of downward motion should be a squeak fit that pulls the shoulders of the neck tight to the body. Good contact inside the joint is especially important on the lower half, down to the heel.
When re- gluing, use just a small amount of glue on the mating surfaces of the tenon/mortise to facilitate an easy reset next time around.

I would think with CNC machining they could get the joints to fit very well the first time...

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Typhoon Guitars
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Nope. All the other handwork that happens post introduces variables that see and seen's can't foresee.

Exactly............!! Easy to have the joint nice and tight at the top but loosing the fit as one moves closer to the bottom.
Tom

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A person who has never made a mistake has never made anything!!!

Thanks guys, Yes it seems fairly straight forward.

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Josh House

Canadian Luthier Supply
http://www.canadianluthiersupply.com
https://www.facebook.com/canadianluthiersupply?ref=hl
House Guitars - Custom Built Acoustic Instruments.
http://www.houseguitars.com

Seems that guitar was constructed in 2007 -- is it the original owner? I would think Martin is responsible under warranty. Did it ever have a neck re-set?

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Ken Cierp

http://www.kennethmichaelguitars.com/

Thanks for that Ken, that was on my mind too.

Martin is an extraordinary company when it comes to standing behind their very fine products and their warranty is among the best in the business, ever! If the current steward is the original purchaser of the instrument a neck reset or a neck coming loose would be fully covered under warranty by Martin. Even if the original purchaser did not register the warranty initially they can still register it now, after the fact, even long after the fact and if this is still their guitar Martin will cover the repairs under warranty.

We participated in helping a client get warranty coverage 50 years after the purchase and Martin was enough of a stand-up company that they agreed to cover warranty repairs 50 years out and based only on a black and white picture of a toothless 9 year old holding the guitar.... Pretty amazing and as a fan and student of how companies do business it was a very impressive interaction to have been able to watch happening.

As for how a company handles revenue recognition with such a fine warranty I am at a total loss but hey it's very client centric and that is ultimately what really matters!

Disclaimer: Although I will always advocate for Martin authorized service centers and obviously have a bias here since we are a Martin authorized warranty center we don't and won't except shipped in work. I turn it down frequently because we don't want it, don't need it, and believe that customers are best served being served by any of the many other Martin authorized service centers closer to home wherever that may be. The statistics for guitars being damaged in shipping is a crying shame and in no way do we ever want to encourage the carnage that the shipping companies (and airlines) are unfortunately known to leave in their wake....

With that out of the way....

It's unusual for a dove tail to come loose as you are describing Josh. I don't believe that I've ever encountered one like this either. Most of the time repair folks have to jump though our sphincters to get the things apart....

As such step one for us if we were doing the work is to determine if someone else has been in there after the thing left the factory. More specifically I would be looking for or inquiring as to if someone else had worked on the instrument prior.

Martin is not known for their dovetails coming loose on the 18's. There were periods when Martin used a bit more glue than some of us would have liked but a dovetail coming loose kind of sort of defies reason when one has a mental picture of how a dovetail works.

The glue is only there to keep things in place where the real mechanical heavy lifting is done by the joint's design clever as it is. Seems to me that for a dovetail to come loose the neck would have to rise out of the joint with the fret board extension being unglued, etc. As such there may be a break or fracture in the dovetail but as to what would have done that it beats the heck out of me.

I guess that if warranty coverage is not appropriate and you do the work you will soon fine out. Let us know what you find Josh?

I had assumed, (maybe wrongly), that the instrument had been worked on before. I have seen dovetails that have come un-done, but, like Hesh, never un-altered from the Martin factory. If you open up the joint and find it was a manufacturing error, an e-mail and a couple of photo's will often get better companies, to cover repairs even for non original owners.

No..... We are talking about a material that used to be alive! It's never going to be as stable as a piece of stainless, for instance. Humidity and other factors continue to have influence on the wood. No getting around it.

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"Act your age, not your shoe size" - Prince

Hey Guys,

He is not the original owner. So I don't think the warranty applies. I don't know the details of the Martin warranty, but I'm assuming it is like most manufacturers, only good to the original owner.

The guitar is in very good shape, other than this issue. I don't see signs that it has been worked on previously and only the dings and scratches you'd expect on an instrument that gets played.

I suppose the dovetail joint could be damaged? But from what I can see with a flashlight, and slipping a piece of paper in around the heel it appears to be intact, just loose. I think with once the fretboard is lifted the neck will come right out, it seems loose enough that I don't think any steaming of the dovetail would be needed.

Whenever I see a decent instrument where I think the repair qualifies as a warranty issue I always direct the customer to an authorized repair centre first. In this case I don't think this qualifies, and the nearest Martin repair centre is a few hours away.

If anyone has more input I'd be happy to hear it. Otherwise, I'll probably take the next off early next week and have a look.

Thanks

Josh

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Josh House

Canadian Luthier Supply
http://www.canadianluthiersupply.com
https://www.facebook.com/canadianluthiersupply?ref=hl
House Guitars - Custom Built Acoustic Instruments.
http://www.houseguitars.com

It happens. Any maker that builds enough guitars, there will be some mistakes, poorly fit "Friday joints" among them. If they fit 99.99% of their dovetails perfectly (which would make for a pretty respectable record), this would still leave at least a few hundred less than ideal joints making it out each year.

It will still need to be steamed out, no question, but it should come out relatively easy.

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Eschew obfuscation, espouse elucidation.

Neck fitting requires 6 months of training before Martin will put you into the group as a regular. The good news (in a way) is that there's no short supply of practice materials such as neck blocks, and necks that failed inspection but aren't worth the time to rework. That was one of the more brutal realities of my time spent with them: seeing a box filled with perhaps 30 necks that could be perfect with a half hour of work, each awaiting their turn to be cut in half on a band saw.

After the initial setup and QC check, all of their instruments are put in cases and left in storage for at least 6 weeks (and they do everything they can to stretch that out longer if possible) to acclimate prior to final setup and checkout. So what you have can happen, but it's crazy rare. When I was with them as an intern during my last semester of high school their failure rate requiring service was well below 1%. It's also part of the reason why factory 2nds don't exist outside of jamming guitars placed in break areas.

As a side note on "Friday joints", it's a good thing their work schedule makes Friday a half day. Yes, I know what you meant... It was just a good opportunity to be facetious.