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I wonder has anyone ever used safety wire for bolt on necks?

It's basically a bolt with a hole drilled through the head, and a wire is threaded through that hole and twisted together, and then anchored to a neighboring bolt in such a way that the bolt could never possibly twist loose.

Because split washers do not work, belleville washers work but it still does not prevent the bolt from turning by itself due to vibrations...

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Cat-gut strings are made from kitten guts, stretched out to near breaking point and then hardened with grue saliva. As a result these give a feeling of Pain and anguish whenever played, and often end up playing themselves backwards as part of satanic rituals.

Typhoon Guitars
http://www.typhoon-guitars.com

I haven't heard of a safety wire being used, but it seems like Loctite Blue or Purple would be a much simpler solution if one was worried about the bolts loosening.

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Once in a while you get shown the light in the strangest of places if you look at it right - Robert Hunter

Anyone in aircraft can tell you safety wire is about keeping the nut from turning, not about keeping tension ON the nut. Besides, how do you propose we do this, Tai? You want the nut or the bolt sticking out of the guitar? Wouldn't a cotter pin work just as well? It's dang sure quicker than tying the safety wire. Let's face it, it's about as practical as roofing your house with chain link fence.

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

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

I've used crinkle/wave spring washers - no loose bolts so far.

Is this even a problem?
And why don’t split washers work?
B

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My memory is so good, sometimes I remember things that never happened.

I only wish that all "problems" were this unnecessary to solve.

I use belleville washers. They work just fine

However, fwiw, I have encountered three Art and Lutherie family guitars which have bolt on butt joined necks that have had loose bolts. Snugging them up fixed everything, not hard to do.

I use belleville washers as well. The heel blocks both shrink and expand due to humidity. The belleville washer have a wider diameter than the spit washers. I felt the larger diameter and the spring in the belleville washers makes them less likely to be impressed into the block.

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http://www.Harvestmoonguitars.com

Like John, I am more concerned with wood movement. I think having a bolt that is easily accessed and tighten-able is more of a priority than immobilizing the bolt.

I have used the split washers (without problems) but for the last several builds have moved over to the belleville washers for the same reason as John.
Never had a problem, but my guitars are not necessarily subjected to big humidity swings like there may be in Taiwan.

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The name catgut is confusing. There are two explanations for the mix up.

Catgut is an abbreviation of the word cattle gut. Gut strings are made from sheep or goat intestines, in the past even from horse, mule or donkey intestines.

Otherwise it could be from the word kitgut or kitstring. Kit meant fiddle, not kitten.

I watched a video on YouTube about how safety wire is installed. Then I thought about what it would take to do that, and later remove it for repair work, inside the body of an acoustic guitar. No, thanks. Even if it did some good (which seems to be in question), it looks like a hard thing to do and undo from inside the box.

I have continued to use the bolts that John Hall used on a couple of kits I bought from him. They have a large head and are tightened with an Allen wrench. The size of the head bearing on the wood might have something to do with it, but in the 9 years I have had guitars out there with these bolts, nothing has loosened. Just an amateur working on #9.

Trying to picture using safety wire pliers inside a guitar...

No need to wire a dovetail

I think maybe the idea of safety wire is a solution searching for a problem. There's reasons nobody does it, (1) it's not needed and (2) it would be almost impossible to do inside the confines of a guitar body. I've done plenty of safety wire on aircraft, and I don't propose to do it where it's not needed.

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Peter Havriluk

you can lock the bolt all you want it is the shrinkage of the wood that will make the bolt come loose

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John Hall
blues creek guitars
Authorized CF Martin Repair
Co President of ASIA
You Don't know what you don't know until you know it

I agree, I use the furniture bolt shown above with no washer. Only loosening I have seen is if the guitar dried out and the headblock shrunk.

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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 used 10-32 fine thread lag screws when I built with bolt-on necks, coupled with large flat washers. These lag screws are commonly used on banjos. I faced the mahogany neck block with a vertical strip of hard maple for the washers to bear against. I put a 3/8" maple dowel in the neck heel for extra strength. Collings also does the dowel, but I didn't know that at the time. I see no reason to use the more common 1/4" bolt, since a #10 screw (or even a #8) is plenty strong enough, and much lighter. The fine threads are better for avoiding the loosening, but you still have wood shrinkage to deal with. That can be minimized with proper seasoning, or even torrefaction.
My bolt-on necks were constructed at least 30 years ago, and I don't recall ever having to retighten a bolt, though one of them was reset about 7 years ago.

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John