Official Luthiers Forum!

It's fairly easy for repair folks to blame poor design or build quality for problems, just as it's easy for builders to blame unknowable maltreatment after leaving the shop.
To take another swing at the poor pulp of a horse, This is the need for Cross training between build and repair!

The longer I do repair, the more I know about what works and what doesn't. Yet, despite this increase in knowledge, I've become slightly more intimidated by what is required to build an instrument and send it confidently out into the world knowing all my ducks are in a row.

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Me too, it's ugly out here. One of my clients left his Heshtone in a hot car in Nashville for a week in the summer.... The only issue was a lifting bridge and that was fixed at no charge because I can. I used to worry about what if this or what if that but after seeing how even some of the best of the factory instruments can be built at least at times and I stopped worrying about my own stuff.

To be clear I respect both building and repair but I will be the first to admit that when I was only building I was VERY ignorant as to how instruments can fail and why. Had I learned repair first it likely would have been the other way around.

With this said lets all agree that we are all perfect and it's the clients who suck big time.... Kidding of course.....

Please use truss rods and better yet if you don't have any great reason why such as an exact replica of something consider double action rods too. You guys may build perfect stuff but it's ugly out here after it leaves your mitts and very likely to get abused eventually.

...which makes me glad I'm out of it.
Ugly out there is when fix a totally dried out mandolin, you tell them to humidify their mandolin, provide a violin Dampit and a year later, you get the instrument back with a soap dish drilled full of holes and a sopping wet sponge inside the case, RUSTY strings (duh!), back separated from the tail block and the back looking like a roller coaster in that area...must be unknowable maltreatment...by whom again? If a little is good, a lot is better, right?

Overhumidification has been a far greater problem than excessive dryness in my clientele. One comes back with concerns about high action and there are a couple of soap dishes in the case and a high output Oasis in the soundhole.

It’s a frickin’ rainforest in there. They never seem to go back where they were after drying out and may require a neck set tweak.

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It's not what you don't know that hurts you, it's what you do know that's wrong.

Yep. I know there's gonna be trouble as soon as the case is opened and I smell mold.

I guess we've arrived at the final takeaways:
Clients suck and the solution is to get out of the business.

Before I started building and repairing I was a client and did exactly the same stuff. I have enormous empathy!

In my previous profession I think most nurses thought their job would be great if it wasn’t for doctors and patients.

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It's not what you don't know that hurts you, it's what you do know that's wrong.

I still prefer and use the simple lightweight single action truss rod.

I've been growing orchids all of my life and find that these instruments make excellent planters..... I call them guitardens... You can just keep the thing in an inch of water and bottom water the roots. . So what if they drip when playing...

Dave Collins does too with the G*bson single action rod his favorite. He would make his own when he was building.

He admits though that for instruments not in his care a double action rod is a better idea for if and when the client lets it dry out. In your climate Clay drying out is not so much of a problem as it most certainly is here with our furnaces on right now and for the next six months or so.

There is beautify in the simplicity of that single action compression rod though, I agree. When servicing instruments with these rods I always take the nut off, lube it up and put it back on so it works well for the next servicing.

I think the problem with the massive over-reaction is more "The Internet"...

On one of the larger player forums - there are a whole bunch of "Priests of Humidification!!"

These fellows trot out into any topic that veers into humidity with a fervor for Converting the Sinners doe their Lack of Humidification and the Righteousness of Humidification!

One recent post that really got me....
Here's a fellow living in Costal South Florida... Chances of LOW humidity are right at 0%. Its swampy there - the average day runs around 70%.... He was looking for DE-humidification advice because all bis guitars sounded dead and thumpy from the moisture... He was also (rightly) concerned about mold....

And out trots the Priests of Humidification Righteousness... Telling him all about how be NEEDED supplemental humidification and how his guitars would all implode and crack to pieces... Supplemental humidification in SOUTH FLORIDA!!!! I had a good laugh and chided these folks a bit over growing moss in the fellow's guitar ... Recommended the fellow get a dehumidifier from BORG and set it at around 45%.. It may stop running maybe 3 days a year down there....

Yes - I get it... The key issue is humidity CONTROL... Keep it in the range YOU are super comfortable and the guitar will be too... Air conditioning/heating companies already know all this and have a whole host of solutions worked out because humidity control is important to your comfort... Most of these solutions are already built in (or can be for a small fee)..

Priests of Humidification..... John my friend can I borrow your excellent term from time to time?

EDIT: My conscience got the best of me, sorry if I offended anyone. I self-deported my prior post.....

Hi all.
This is good advice. Thanks Hesh. A couple points from a guy with a near ulcer and nervous ticks... Uhemmm me. I still use a single action 3/16 inch rod that I fabricate myself. When my Pleck machine is down (Kidding) i resort to leveling the fretboard, after fretting and inlays using a radius sander. Then fret the board off the neck. I keep this fretboard at low humidity before and after this. I also have the neck complete and make sure it also is at EMC but low. I give the rod a quarter to half a spin and sand it flat again taking out a little curve. Now here comes the sticky part. I glue them together. Then again I put a little more tension on the rod and level again.


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Ken

Just wondering and pondering the situation from afar. Do you think he might need a different guitar for stage use?


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Ken

Hey Ken when are you coming to visit now that you're in the area. We can enjoy some Protonix together!

Soon! Do I need an appointment. How about a fret job. Milk of magnesia?


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Ken

Heck no, we pay tens of thousands of dollars a year to have normal retail hours.... so no appointments required. Our hours these days since we are not a store and since we can are M - Wed 10 - 5 and Th and F 9 - 5. Stop in any time but I'm not always there, either is Dave so might be best to coordinate a day and time that we both can visit with you.

Tom R. from the forum is meeting us at our shop today at 10 and he just moved to the area too.

Absolutely my friend...

Back to the topic at hand...

I am finishing up a 1940's Harmony Stella rebuild. It's a Grand concert size.. Solid birch box... Poplar deep V neck.. And originally no trussrod...

Well - it was a complete basket case... It came to me in pieces - just a body and a neck.. No metal. Fretboard was toast....

So - in the process of the rebuild I installed a double acting truss rod.. Sacrilige I know on an old instrument like this... Call me a sucker for modern convenience.... But so many of these old instruments simply went in the trash when they needed some work because your only option is very expensive repairs...

Well.. I levelled the fretboard dead on and fretted it... Got strings on it a week ago and that old 1" deep V neck STILL has not pulled up for a little relief.... It's still dead level.... I am going to give it another week - but most likely, I will end up cranking a bit of relief into it via that double acting trussrod.. Sha-Zam....

If anyone is in the market for a DA truss rod check out Bitterroot Guitars,

http://www.bitterrootguitars.com/category-s/1911.htm

Excellent prices, especially in volume and a very high quality DA truss rod.

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tim...
http://www.mcknightguitars.com

Does anyone make a Titanium rod. I need one


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Ken

Ken,
I think Mark Blanchard or John Osthoff does.

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tim...
http://www.mcknightguitars.com

And Why They're Not:

I don't have any issue with the concept of double-acting truss-rods, but every thread needs a Devil's Advocate, so with the court's permission, may I approach the bench?

Let's start with the obvious (and most important): double-acting rods can create problems that don't exist in guitars with single-element rods, non-adjustable rods, or no neck reinforcement.

It's been a while, but I used to do quality evaluation for double acting truss-rods for a small manufacturer of high-end guitars. Here's a list of problems I encountered on a regular basis with the double-acting truss-rods:

#1: neck buzzing--I saw hundreds of these. To be fair, most of these didn't buzz when played. (They rattled like the devil when you rapped on the back of the neck with your knuckles.) Some that buzzed when playing were cured with a little tension on the truss-rod (and a little loss of playablity because now the neck relief wasn't optimum). Some of those that didn't buzz initially would buzz at random moments of humidity change--lots of fun for the repairman.

#2: Weld-fouled threads--I came into guitar building from a background in racing bicycle manufacture. All of the welded truss-rods I've seen have had amateurish welds. Let me say that again: ALL OF THE WELDED TRUSS RODS I'VE SEEN HAVE BAD WELDS. I'm not as much in the loop as I used to be, but every time I see a discussion here with pictures of a welded truss-rod, it takes me back. Fouled threads will limit adjustment.

#3 Cracked welds--ALL OF THE WELDED TRUSS RODS I'VE SEEN HAVE BAD WELDS. I would say that at least 70% of the welds I looked at had substantial cracks. In a very small percentage of the welds, the crack had propagated far enough to render the rod useless. Cracks propagate over time.

#4: Limited adjustability--Some designs rely on a difference in thread pitch between the two ends to achieve the relief adjustment. This results in a very precise adjustment that bottoms out very quickly. When you're done, you're done--at that point, you might as well not have a truss-rod

#5: Corrosion--Over time, the threads on any truss-rod may corrode. When that happens, you may be back to the repair options of a no-truss-rod neck. Multiple element truss-rods (single-acting, or double-acting) have more places for corrosion to occur. If the protocol for installing the truss-rod involves some sort of silicone sealant, it's important to note that most silicone sealants are corrosive. (Again, time is your enemy.) Non-corrosive silicone is your friend.

#6: Stripped hex socket. Many of the truss-rods I saw had poorly formed Allen wrench sockets. It was not uncommon for an accurately sized Allen wrench to spin in the socket of a truss-rod head that had been formed with an over-sized hole, and a hex-broach that just touched the corners.

#7: Truss-rod blows out the back of the neck. Rare, but this has been mentioned several times on the forum.

#8: Weight. For some playing styles (flamenco), neck weight is critical. Maybe Stuart's designs would solve that problem, but most truss-rods are a good deal heavier than Spanish cedar.

#9: Canary in the coal mine. There are several guitar problems that serve as a warning for something more serious. Low action and buzzing strings? Fret ends sticking out? Excessive relief? All of these are symptoms that precede cracks.

Much different experience with DA truss rods here:

1). Buzzing truss rods because they are double action is not been something that we've seen much of. On rare occasion an unengaged rod can rattle but simply just barely engaging it does the trick. Barely engaging need not fundamentally change that perfect relief. I would disagree with your contentions here. Buzzing rods do exist but the percentage of guitars doing this because of the truss rod is pretty minimal AND not exclusive to DA rods, SA rods can do it too.

I'll add that some of the rods that are actually more well known for rattling are SA rods. Fender for example can do this and that's why there is a repair person's fix of removing the dots, installing set screws that engage the rod mid length to support it and covering up the set screws with the dots reinstalled. We've done this on these rods and have never had to do it on a DA rod.

2). The Allied or Blanchard rod had better welds and I've not experienced fouled welds. Sloppy welds yes, welds that need to be filed, yes but not fouled welds. LMI rods from say ten years ago did have some bad welds and some welds that failed but this has not been my experience with the Blanchard rod or the Martin DA rod.

3). Never saw a cracked weld but again did read about some here and it was always the older LMI rod ten years ago or so. Lots of threads here advising testing the weld prior to installation.

4). I've never had a rod bottom out because it's a DA rod. Instead the Blanchard rod with different threads has the advantage of very easy adjustments making any damage to the adjuster from the wrong wrench less likely because it requires very little engagement force to turn the adjuster.

5). I've not seen or experienced any corrosion with the Blanchard "stainless....." rod or Martin DA rod. Corrosion is not limited to DA rods, SA rods do it too. Step one with G*bson SA rods is removing the adjuster and lubing it up because they corrode and commonly do so, again this is a SA rod.

6). Using the wrong wrench is not exclusive to DA rods either, it happens with SA rods and I would again argue that rods that require more force to use are more likely to eventually have damaged adjusters from improper wrench sizes.

Fender SA rods have a very shallow engagement depth and are known for breaking off the tip of the hex wrench (and getting it stuck in the adjuster...). I am unaware of any DA rod known for a shallow adjuster.

7). The only blow outs that we've seen and we've seen a few was the SM Hot Rod DA rod and that one has extra depth making for a thinner back of the neck. SM has since offered a shallower rod. I've never seen a Martin DA rod blow our the back of the neck or any other for that matter. I'm sure it can happen but this is not an epidemic by any measure....

8). Truss rod weight need not be a problem for instruments not equipped with truss rods at all. Classicals and Flamenco guitars rarely have rods with the exception of some low end, student Cordobas that are currently on the market and a few other examples. But the norm for these instruments is no rod at all.

9). Your symptoms are of a dry guitar not a defective truss rod or the existence of any rod at all. Proud fret ends are from a shrinking neck and frets that don't shrink, etc. None of this is related to the Truss rod EXCEPT that a dry, back bowed neck can be saved.... and often is saved.... by a DA rod that can bring it back to flat or some relief when the neck becomes permanently back bowed from exposure to an overly dry environment.

I may be misunderstanding your meaning here but a DA rod does not preclude this canary from going teats up and being that warning sign. Even with a DA rod these tell tales still occur and can signal other issues. A DA rod gives us options to address some issues that we don't have with a SA rod or no rod at all.

Most of what you are citing here is not what we experience in the repair world from DA rods. I'll reiterate that instead DA rods can save an instrument and often does in our climate.

Tell me more about non corrosive silicone...

1. Just a bit of info on the Martin SA rod. They are made in Japan by Gotoh and are very high quality.

2. When installing any truss rod, we've always removed the nut (on SA rods) and greased the threads prior to installation. This will keep glue from interfering with the thread operation.

3. DA rods also need lubricated with a light penetrating oil, on both ends of the rod and nuts. Same reason as above.

4. The oil, or grease, puts a protective boundary layer of oil between the corrosive sealants and allow the rods to work trouble free for life.

5. The Bitterroot rods are on par with the quality of the Gotoh rods in terms of construction and welding methods. I used to be a certified welding inspector, in another life, and I am fairly certain the welding is done by the TIG process as there is no slag inclusions, MIG wire arc strikes or chicken poop build up on the welded surfaces.

They have a couple of unique design features in that they have a sleeve welded over the rod nut, which prevents glue migration during installation. They also install shrink wrap tubing over the rod and bar assembly to prevent rattle.

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tim...
http://www.mcknightguitars.com

The two products I've used are Dow 748, and GE RTV 11. McMaster Carr carries them. Regular hardware store silicone sealant gives off corrosive fumes as it cures. The Dow product looks and acts like any other silicone sealant, but is formulated for electronics applications, so it doesn't give off corrosive fumes. The GE product is a two-part catalysed sealant. It is also non-corrosive. Before it sets up, it is liquid enough to be forced through a 16 gauge hypodermic needle. On guitars with buzzing truss rods, I pull the second fret, drill a 1/16" hole through the fret slot into the truss rod channel, and inject the sealant until it flows out inside the guitar. (Some tape and towels inside the guitar keep things tidy.) It sets up in about an hour, and forms a medium density non-sticky rubber.