Re-Fret Issue -- Ends of frets not seating

[mr smits]

Hey all.

I've done one refret ever, and it turned out great. But in that case the frets removed where the same size as the frets replaced.

With this problem I'm having today, I'm replacing vintage size frets with 6105 frets. They are pre-radiused to 9.5". When I hammer them in, the center goes deep enough, but the ends do not. The ends on both sides pop out (not a lot, but I can fit paper under them). I thought maybe there was glue or something holding them up. After looking some more, it seems the fret tang is slightly longer. I don't really understand what's happening. Why would the center of the fret bang in all the way, and the ends do not?

I measured the thickness of the tangs using calipers, and the new, larger frets are .21, and the smaller vintage were .19. It seems close enough that they should bang in just fine. The height of the tang looks to be .77 and .61. This might be where the issue is? But I'm just not experienced to understand what is going on.

Any help would be appreciated.

P.S. I have the basic tools for a fret job but nothing specialized like crimpers or fret barbers, etc.

Thank you.

[Mark Fogleman]

I would pull the fret(s) and use the dull side of a utility knife blade with your tang depth scratched on it with a caliper to test depth and clean out the slot. If adequate the slot is too wide. Then it's either use something to expand the crimps (I've used a finishing nail and hammer in a few of the edge crimps) and/or CA and accelerator while pushing down very hard with the face of the hammer or diy profile mounted in your drill press to glue it in.

[Todd Reich]

It seems to be an issue with the depth of the fret slot(s) combined with the height of the tang of the new fretwire. I'd say there are two possibilities:

The old frets had a shorter tang length than the ones you have now, and the fret slots were cut with that fretwire in mind. For example, if the old fretwire had a .61 tang, they may have cut the slots in such a way that upon being radiused the depth of the slots ended up being an acceptable depth for that wire on the outside edges where the cut would be its most shallow, for sake of example, let's say .68; This would manifest in plenty of room to accomodate the old fretwire, but would be too shallow for anything like what you're using.

There could be a build-up of debris/glue on the edges of the fret slot that hasn't yet been fully cleaned-out. I'd think this is less likely if you experience the same issue to approximately the same degree on all fret slots; That would seem to indicate the prior possibility.

StewMac sells a fret slot depth gauge, but you can also make one yourself with a razor blade or sheet metal stock (Mark Fogleman's suggested method is excellent for this purpose); Double-check the depth of your slot relative to the height of the new tang. If it's too shallow, it's a simple matter of deepening the fret slots to accommodate the increased height of your new wire's tang.

[Russell Vance]

Hi Mr Smits, Have you checked the fingerboard radius?  After that its a case of matching the radius of the fret to the actual board and then cleaning out or deepening the existing slots.   Once clean inject some water into the slots to plump up the wood a little (and yes, I know that the wood is endgrain but it will tighten up a bit anyway).   Hammering frets is also not my preferred way in this day and age but if you have limited resources so it is.

Rusty.  

[Mike Kolb]

Ditto about making sure the slots are clean & deep-enough.  Also, it's a good idea to slightly over-radius the frets themselves so that (when just held up to the fretboard before installing) there's a glint of daylight in the center.  

When hammering-in frets, I'll use a rapid succession of short, quick blows and seat the ends first, working in from both sides towards the middle.  Once the ends are seated nicely, any 'slack' in the center can work it's way to the outside and the frets will creep outward along the existing 'track' of the seated ends. 

As with most things, it's probably tougher to describe than actually do! 

[mr smits]

Thanks all.

I haven't had a chance to try the suggestions here, but I will soon and report back on what the issue is.

Are the fret saws stewmac sells worth it? If so, they have three sizes -- which is the most useful size? Is there a cheaper option that does the same thing? Thanks!

[Mark Fogleman]

How cheap? Harbor Freight has a flush cut saw that will get you by if you just need to touch up a few existing slots. Check the kerf on scrap as mine is about 20 years old (the version they have now is probably different) but it mics out to .025" and leaves a clean cut. I find lots of uses for it in the shop so a good tool to have if you don't have one. I use a page from an old phone book when using it as a flush cut saw to protect the surface.

[mr smits]

Thanks!

I think I am going to invest in a proper saw because I think what you guys mention about the slot not being fully cleaned, especially on the edges, is probably the issue. Do you think I should do the .020 or .025? The tang of the new fretwire is .021.

Here are the options on stewmac: https://www.stewmac.com/Luthier_Tools/Types_of_Tools/Saws/Refret_Sa...

There is also this option: https://www.stewmac.com/Luthier_Tools/Types_of_Tools/Saws/Japanese_...

I'm not sure which would be best so any advice is welcome. Thanks guys.

[Mike Kolb]

My experience has been that saw kerfs can vary a small bit, regardless of the advertised number.  If there are two identical saws, it always seems that one's a bit more or less generous than it's drawer-mate.   It never hurts to "mic" the saw kerf before cutting.

Secondly, when determining the slot width, keep in mind that a slightly tighter fit will tend to produce a backbow on the neck. 

So if your fret tang is .021" and the saw kerf is .020"... the wood on the side of the slot has to go somewhere and it gets compressed by a very small amount.  Multiply that small amount of compression by 'X' number of frets and there's where an overall backbow is introduced.

This effect can be used to an advantage to help control a somewhat rubbery neck but, in any event, it's a phenomenon to be aware-of.

[mr smits]

Ah yeah, I have read about the compression in the past. Can a truss rod adjustment fix that?

Would you go for the larger saw of .025 then? Or would that create the opposite problem where the tang is too loose?

[Mike Kolb]

In a word, yes, a truss rod adjustment can "fix" a compression backbow, but the idea is to not introduce the backbow in the first place... unless that's what you're intending to do. 

A lot of the choice made in fret slot width is dependent on the wood itself.  I tend to be a bit generous in width with a hard ebony, but go a little tighter with a softer rosewood. 

"Experiment with scrap" is a great mantra. Get some scrap of the fingerboard wood you'll be using and do some trial-and-error fitting. 

Also, get a great book on fretting!  There's lots of experience out there by real pros who were kind-enough to share the wealth. Frank has lots of great advice on frets.com, and then there's this book put out by StewMac.

[Russell Vance]

Hi All,

We use .023 blades for rosewood and .025 for ebony with our standard fretwires .05590 which is .020 tang and 51108 which is .023 tang.  New fret slots around this dimension will give us a slight compression fit which,along with cyanacrylate bedding,  is essential to good consistent tone transfer.  We use two way truss rods and I like to have to tension a neck into relief to ensure the truss rod the neck and the fundamentals and harmonics stays put when the neck gets a pounding.

However, for reconditioning used fret slots I use a narrow pull saw blade as the fret slots are already oversized from extraction (as a general rule) and any help to get some compression back into the neck is a bonus. 

My view is that good fret work requires appropriate and quality tools for consistent results.  Next time I see my surgeon he won't be using an Exacto knife and a kitchen spatula.

Regards, 

Rusty.

[mr smits]

Some new information: the old frets don't seat in the slot anymore, either. This is strange. I thought I could just put those back in. But the same issue happens. The ends of the frets won't sit totally flush, but the center does.

When I purchased this neck they were flush. Does this give any clues as to what could be going on?