Fret Rockers

Bellycaster

Do Luthiers use the same size Fret Rocker for Bass and Guitar. As fret spacings are different I ought to ask.

I'd like to check the frets on my Jazz Bass.

Also, would a numpty like me be capable of lowering the fret height should there be a high one or two. Don't know what tools used for frets: File, Stone?

Thanks.

Funkfingers

I use the same Fret Rocker tool for guitar and basses of scale length up to 35". It could probably cope with 36" and, maybe, even 37".

BillDL

Bellycaster said:

Also, would a numpty like me be capable of lowering the fret height should there be a high one or two. Don't know what tools used for frets: File, Stone?

Your choice of tool will be dictated by how many high frets you find, and how much higher they are than the surrounding ones.  If you have more than a handful of high frets it may be better to remove the neck, straighten it using the truss rod, skim all the frets using fine abrasive on a beam or on a radiused block of wood, and then use either a recrowning file of the appropriate curve/width or a triangular file to reapply the apex/crown.

Where you find high frets, the fret most often isn't above the adjacent frets by the same uniform amount across the entire width of the fretboard.  It will usually be higher at one or other or both sides or only in the middle.  Often you will have a fret that's high on the treble side in towards the centre and it's then perfect on the bass side, or vice versa.  If you are "spot levelling" selective frets you need to be aware of where on the fret it is high otherwise it's very easy to accidentally take off material where it wasn't needed.  The easiest way to assess a fretboard for high frets is to use a felt-tip pen and carefully mark the crown of the frets where they are found to be high (mask off the fretboard if it's maple).  You can very quickly then assess whether you can spot level them or if there are too many high frets whereby a fret skim / level would be better and easier.  You can alternatively draw 3 columns on a sheet of paper to represent left - middle - right, draw 20 fret lines across it, and mark on each fret line where it is high.

Assuming your fretboard only has a few high frets.

If they are only a gnat's whisker high you MIGHT be able to take off enough material by masking off the fretboard either side of the fret (or use one of those flat stainless steel fretboard protectors with a slot wide enough for the fretwire on bass guitars) and use a piece of fine wet & dry paper (P400 or P600) with your thumb or finger back and forward along the length of the fret while checking frequently with the fret rocker.  Using a finger or thumb allows the abrasive to conform to the crown of the fret and you may not even have to recrown the fret.  If the fret is a bit too high for wet & dry paper to reduce it in height without spending an hour sanding away at it, then you would need a very fine file.  You could use one of the fine flat files from a set of "needle files", or a triangular file that has had the 3 sharp and rough corners ground off to leave a safe edge or a fine file with a concave that's a bit less radiused than the fret's crown.  There are various types of files you can use for this, and some people have even been known to use a fine fingernail emery board.  All you do is file along the length of the fret (or wherever the fret is high across its width) concentrating on the top, but while you are doing this you can also try and go down either side of the apex to try and keep the rounded crown.

If you have a couple of frets adjacent to each other that are high you can use a short fine fret levelling file (eg. the mini diamond fret levelling file) to file across the frets going along the length of the neck or from side to side along the lengths of the frets.  No, I am not in partnership with Chris Alsop, but he makes and sells some very nice luthiery tools.

If you have to take off a reasonable amount of material from the top of some frets whereby the apex is flattened, you would need to reapply that convex crown using a file with a concave size and width that only removes material from the top corners of the flattened fret without touching the top, like the larger radius ones here.

Bellycaster

Thanks @BillDL for that very comprehensive description. It sounds scary but probably isn't, but deffo skills involved. I'd probably manage the wet and dry method

I put some 40-95's on the Jazz Bass tonight, which I was gonna do anyway and I've adjusted neck relief and string height. I'm quite pleased with the results as there is now only a slight buzz on the D string at 19th fret. Amplified it doesn't really show much. Not that I'd play up there much anyway.

I also inspected the frets to see if any had lifted a little and it appears not. I'd assume that would be easy to spot if so.

I might buy a fret rocker anyway to start with just to do my own checks. Will any do? Is there owt to avoid as I've seen prices vary from very cheap upwards.

BillDL

If that's the only buzzing fret you're getting with an acceptable action, then I wouldn't bother, especially if you don't hear it when the bass is amplified.  It's almost impossible to completely eliminate very slight buzzing when played acoustically if you want a lower action.  It's whether you hear it when amplified that really matters. By all means rub the affected fret with fine wet & dry paper and see if it lessens the buzz. It probably wouldn't take much rubbing and it's your last fret anyway.  If it's buzzing when you fret the D string at the 19th fret, then the 20th fret will be the one that's high. It's amazing how such tiny increments can affect the fretting.

You brought up an important thing that I forgot to mention.  If you have any high frets, then check first to make sure thay aren't lifting before filing or sanding off any height.  It would be most common at the ends of the frets, and often a slightly lifted fret can be reseated with a gentle tap from something heavy but soft enough not to dent the fret.  You can get small fret reseating tools that are really just a brass centre punch with a concave at the end that goes over the fret's arch, but often a sharp tap with the back of a plastic-handled screwdriver will reseat a fret. If it goes down but springs again, then it needs to be glued and pressed down until the glue dries.  If it doesn't go down, then the fret usually has to be pulled to clean out or deepend the slot where it won't bed down.

Bellycaster

BillDL said:

If that's the only buzzing fret you're getting with an acceptable action, then I wouldn't bother, especially if you don't hear it when the bass is amplified.  It's almost impossible to completely eliminate very slight buzzing when played acoustically if you want a lower action.  It's whether you hear it when amplified that really matters. By all means rub the affected fret with fine wet & dry paper and see if it lessens the buzz. It probably wouldn't take much rubbing and it's your last fret anyway.  If it's buzzing when you fret the D string at the 19th fret, then the 20th fret will be the one that's high. It's amazing how such tiny increments can affect the fretting.

You brought up an important thing that I forgot to mention.  If you have any high frets, then check first to make sure thay aren't lifting before filing or sanding off any height.  It would be most common at the ends of the frets, and often a slightly lifted fret can be reseated with a gentle tap from something heavy but soft enough not to dent the fret.  You can get small fret reseating tools that are really just a brass centre punch with a concave at the end that goes over the fret's arch, but often a sharp tap with the back of a plastic-handled screwdriver will reseat a fret. If it goes down but springs again, then it needs to be glued and pressed down until the glue dries.  If it doesn't go down, then the fret usually has to be pulled to clean out or deepend the slot where it won't bed down.

Thanks again. I've watched a few StewMac videos and seen a selection of the files that can be used. I admire the skill of using a flat file to create a rounded crown. I think if I did it I'd need one with the form already on

Just another question: When checking with a Fret Rocker, would I need to remove the neck of the Guitar or Bass in question.

I've gotten the Jazz Bass almost perfect now. The action is good and I'm as good as rid of the buzz up the dusty end.

BillDL

You can use a fret rocker (in order of ease combined with accuracy):

1. On a neck that is still on the guitar (strings removed) and has been straightened using a notched straightedge so you know it's the fretboard that is straight and not the line across the tops of the frets that may be crooked,

OR

2. On a neck that has been removed and straightened,

OR

3. On a neck that hasn't been straightened and is still in slight relief from full string tension on the guitar.

No. 3 is the least reliable and would normally only be used to locate and spot level one or a couple of troublesome frets in a hurry or find frets that are a fair amount higher than adjacent ones.  The fret rocker spans 3 frets.  When the fret in the middle is high it will rock from side to side on the lower frets at either side.  If there is relief on the neck, albeit only about 0.012" (about 0.3mm), the fretboard is in an arc with the frets on the inside of the concave.  A fret in the middle on a fret rocker may not register as high if it is just a teeny bit high because of the very slight arc but it could be just enough to buzz with a low action.  All the string cares about is the next fret up from the one being fretted, and ignores the fret behind it.  Ideally you wouldn't be wanting to file frets down while the guitar / bass is strung to tension.  As well as it being harder to file a fret underneath strings, you could end up taking off too much.  There are files that have been made that allow you to spot level frets while the instrument is strung to tension, but they are best left in the hands of the experts and only for certain circumstances.

If the strings are removed an electric guitar neck will either flatten out pretty straight or sometimes go into a tiny back bow if the truss rod had been tightened to straighten it against the string tension.  A bass neck will almost always go into a back bow without string tension, so you would need to relax the truss rod to level the fretboard.  If you tried using the fret rocker on a neck that was in a very slight backbow, it's possible that most of the frets in the middle of the neck would register as high because it's now has a very slight radius with the frets on the outside of the curve and the frets either side of a single fret on a curve will be lower.

Bellycaster

That all makes sense, cheers @BillDL ;

Adey

I've got some of those small diamond faced tool sharpening "blades". It's about 2" long by 1/2" wide. I use the finest one to rub down high frets to stop a buzz. You can use it across a few frets to level them up, but do the pushing above the one that's high. As they are only a few mm thick, you can use it with the strings in place too.