Flat Fretboard Thickness

[LowB_FTW]

How thick should a flat fretboard be?

A quick Google tells me the thickness of a radiused fretboard, I'm guessing it has to be a certain thickness to account for the thinner edges? But what about flat ones?

 

Mark

[Johannes]

I haven`t heard any rules about this subject. I think it depends very much about overall instument and neck construction. It wouldn’t hurt to make it thick enough to have some material for some future refrettings or in case of a fretless sanding/resurfacing.

[BigRedX]

Thick enough so it still has sufficient structural integrity when the fret slots have been cut?

 

Paging @Andyjr1515

[Andyjr1515]

27 minutes ago, BigRedX said:

Thick enough so it still has sufficient structural integrity when the fret slots have been cut?

If the fret slots are being cut before fitting to the neck, then yes.  And if the frets themselves are going to be fitted before gluing to the neck, then especially yes

 

Just to explain:

 

• Fretboard glued before slotting - structurally, the board can be as thin as you like because the neck provides the structural integrity
• Fretboard glued after slotting but before frets are fitted - then the extra thickness below the bottom of the slot is only needed to hold it all together while you handle and clamp it.  It depends on the wood, but down to 1mm remaining after the fret slots have been cut would normally suffice.
• If the frets are fitted before the fretboard is glued to the neck, then it needs a bit more remaining thickness...but the exact amount is a bit of a judgement call.  Here, the remaining thickness needs to withstand the side forces (and if hammering, percussive shock) that hammering or pressing in the frets makes.  I would personally tend towards 2mm remaining at the bottom of the slot.

So, and this is only my own view - for a flat board - given a tang slot depth of, say, 2.5mm, then I would be considering 3.5mm as the absolute minimum if I was fretting after gluing to the neck, and 4.5mm as the absolute minimum if I was fretting before gluing to the neck.  In terms of radiused necks, I personally aim for 6mm-7mm at the thickest point, depending on the radius.

 

Other folks may have different and valid views and experiences, of course 

[SpondonBassed]

59 minutes ago, Andyjr1515 said:

If the frets are fitted before the fretboard is glued to the neck, then it needs a bit more remaining thickness...but the exact amount is a bit of a judgement call.  Here, the remaining thickness needs to withstand the side forces (and if hammering, percussive shock) that hammering or pressing in the frets makes.  I would personally tend towards 2mm remaining at the bottom of the slot.

 

When Jack was making one of his ukuleles he did it this way.

 

He pressed the frets in with a modified mole grips that applied an even pressure across each fret.  The fretboard became quite curved with the combined pressure of all the fret tangs and it required a firm clamping when he glued it down.

 

I can't remember the overall thickness of the fretboard but it's worth having a bit of extra meat on it if you do it this way.

[Norris]

Of course if it was fretless as well as flat, a piece of veneer would suffice

[LowB_FTW]

Thank you to everyone for posting so far in this, it has somewhat set my mind at ease regarding this.

 

Mark

[LowB_FTW]

10 hours ago, Norris said:

Of course if it was fretless as well as flat, a piece of veneer would suffice

This has me intrigued now about a fretless, and I don't even play fretless! 😂

 

Mark

[3below]

The four I have built with flat fretboards have been 8mm  thick. I have slotted two of them with the board glued on the neck blank.  The other two are fretless.  The downside of this is you are left with not much trussrod depth  if you want a ~ 21/21mm depth.  If (like me) you are ok with 'baseball bat' necks (think some Warwick basses) then all is good.  I personally really like flat fretboards.