Nut re-worked in place?

[Skip@sealevel]

Do any of you, as part of a setup, fill existing nut slots and attempt to re-cut the slot with the nut still in place? If filling is done, what do you use?

[Bruce Sexauer]

When CA came along many people used it with baking soda or other dust and filled in nut slots and then refilled them. Over time I have found that this is a substandard fix, it is both too soft and also turns ugly over time. It works for a while,mesoeciallynif youndont try to make your ramps state of the art and instead add a few thou of clearance.

My current fix, when a new nut (the right fix) is not on the table, is to cut a tapered slot about a third of the way into the finger board side of the nut and glue a piece of bone into it. The wide end of the taper is the width of the string and tapers down to nothing. This allows an actual bone release for the string, and is invisible when installed. You do have to remove the nut, but that is generally no challenge.

[LouieAtienza]

Originally Posted by Bruce Sexauer

When CA came along many people used it with baking soda or other dust and filled input slots and then refilled them. Over time I have found that this is a substandard fix, it is both too soft and also turns ugly over time. It works for a while,mesoeciallynif youndont try to make your ramps state of the art and instead add a few thou of clearance.

My current fix, when a new nut (the right fix) is not on the table, is to cut a tapered slot about a third of the way into the finger board side of the nut and glue a piece of bone into it. The wide end of the taper is the width of the string and tapers down to nothing. This allows an actual bone release for the string, and is invisible when installed. You do have to remove the but, but that is generally no challenge.

It took me a while to decipher this, but that's actually a pretty good idea I never thought of before....

[Skip@sealevel]

Bruce thanks for your comment here. It was quite informative. I realize removing and even replacing with a re-slotted nut is almost always accepted practice as part of a proper setup, but am always interested in alternative approaches in the context on unusual situations. The learning never ends and that's a good thing.

[redir]

Some nuts are finished in place and are probably better off staying that way. I have used the CA and baking soda method in the past but I don't trust it either for longevity. I don't recall ever having a customer come back with such repair but in my tests it does just seem to be softer and therefore is probably not the best fix. It sure is easy though.

I now use a mixture of bone dust and CA. You can make a pile of bone dust easily with a spare chunk of bone and a piece of 180 grit paper. Then just fill in place like you would do with baking soda.

[Hot Vibrato]

Originally Posted by redir

Some nuts are finished in place and are probably better off staying that way.

Not an option if the slots are too deep and the customer wants it done right.

Originally Posted by redir

I have used the CA and baking soda method in the past but I don't trust it either for longevity. I don't recall ever having a customer come back with such repair but in my tests it does just seem to be softer and therefore is probably not the best fix. It sure is easy though.

I now use a mixture of bone dust and CA. You can make a pile of bone dust easily with a spare chunk of bone and a piece of 180 grit paper. Then just fill in place like you would do with baking soda.

I've done this with both baking soda and bone dust, and both are equally substandard. It's okay for a quick fix or on a cheap guitar, but if it's a good guitar, I'll just make a new nut.

[redir]

I don't think bone dust is substandard. It's a matrix of the same material that the nut is made out of. It's better to not replace a nut on a vintage instrument so in that case it's better to fix it. I've been doing it this way for many years and have yet to see bad results. Of course a new nut is better but from my experience this fix works well in any case and is very appropriate in certain situations.

And of course it depends on how blown the nut is in the first place too. These fixes are for very small adjustments. You could do an in situ fix similar to what Bruce outlined to by dremmeling out a slot and inlaying a solid piece of bone.

[Hot Vibrato]

Originally Posted by redir

I don't think bone dust is substandard. It's a matrix of the same material that the nut is made out of...
...from my experience this fix works well in any case and is very appropriate in certain situations.
...I've been doing it this way for many years and have yet to see bad results.[

Really? You've never noticed that "plinking" sound when you tune up your B or high E string after it's been filled? I've filled nuts hundreds of times, using the same method as you, and there's no doubt in my mind that glue and bone dust is much softer than bone. IMO, it's just not an adequate repair, and it should never be used on a guitar that belongs to a professional level musician. But it's fine for a quick fix or for a cheap import guitar.

Originally Posted by redir

It's better to not replace a nut on a vintage instrument

Only if it's a museum piece. If the guitar is to be played, a new nut is far superior than one that has been filled with glue and dust. Furthermore, many vintage instruments have nuts which are poorly spaced, or have been sloppily adjusted by someone who didn't have the proper files (or both). Therefore, a nut which is finely crafted by a skilled luthier in his workshop is way better than a nut that was made by a factory worker sixty years ago.

This vintage BS has gotten ridiculous. Do you want to play the thing, or just look at it?

[murrmac123]

UV cured composite dental filling is the state-of-the-art material for nut slot filling .... harder than bone and can be color matched exactly.

[redir]

I've never noticed plinking with the bone dust fix before. As for vintage, heck yeah I just want to play it but for those who want resale value you always have to take that into consideration. I agree, it's a bit out of control but that's just the way it is.

[redir]

Originally Posted by murrmac123

UV cured composite dental filling is the state-of-the-art material for nut slot filling .... harder than bone and can be color matched exactly.

Where do you get it?

[Hot Vibrato]

Originally Posted by murrmac123

UV cured composite dental filling is the state-of-the-art material for nut slot filling .... harder than bone and can be color matched exactly.

No kidding? What does the UV curing process entail? I know a couple of dentists. Maybe I could get my hands on some of that stuff. Sometimes the only reason for scrapping a nut is because one of the slots is too deep. I'd love to be confident that a nut slot fill is going to work well in the long term. I mean, I don't mind making a nut, but it usually takes me at least couple of hours to go from cow femur to a polished and adjusted nut. If I could just fill the slot instead, that would be a game changer for me.

[arie]

Originally Posted by Skip@sealevel

Do any of you, as part of a setup, fill existing nut slots and attempt to re-cut the slot with the nut still in place? If filling is done, what do you use?

i can work on a nut in place. i'll do this to fit larger strings (if asked for) and to provide better ramping. also, a majority of the nuts i see on factory instruments are cut so terribly wrong it insults me. professional ethics compel me to deal with a crappy nut before it leaves the bench. fwiw, nobody i deal with wants a "dust fill'' on a nut. i'd rather hack out a temp. nut from corian, or do a under the nut shim and re-cut then go that route.

the usual tools: nut files, a series of fine papers, optics,..

[murrmac123]

Originally Posted by redir

Where do you get it?

Originally Posted by Hot Vibrato

No kidding? What does the UV curing process entail? I know a couple of dentists. Maybe I could get my hands on some of that stuff. Sometimes the only reason for scrapping a nut is because one of the slots is too deep. I'd love to be confident that a nut slot fill is going to work well in the long term. I mean, I don't mind making a nut, but it usually takes me at least couple of hours to go from cow femur to a polished and adjusted nut. If I could just fill the slot instead, that would be a game changer for me.

I get mine from my dentist, have done for years. ... the stuff goes out of date, and they have to check before they use it in a dental application, but it still hardens perfectly satisfactorily.

You don't need to buy a special UV lamp ...the modern stuff cures with any bright LED light, although back in the day they had to use specialist UV equipment to cure . It's just convenient to call it UV composite, although technically it shoudl really be re-labeled as "light curing composite"

What you really need to get from your dentist is a bottle of out-of-date bonding agent to use before applying the composite ... I imagine the composite might adhere satisfactorily without it, but I have always used the bonding agent. It is however horrendously expensive to buy new , even for a 5ml bottle.

It's not difficult to wide and deepen a slot, fit and glue a piece of bone or ivory, then reshape and recut it with the nut in place. I prefer to do it that way since the nut is held neatly in place.