Brad H

Fitting New Fingerboards to Old (Not new) Violins

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Maybe I need just moral support but, more likely, there are techniques and tips which would help me improve the task of fitting a new board to a non-new violin.  Here is what I do:

1.  "Flatten" underside of board.

2.  Align board on neck, clamp, and then scribe the neck outline on underside of board with awl.

3.  Use shooting board to plane sides of board within 0.5 mm of scribed lines....(hopefully getting close to 24, 32, 42 mm marks).  I haven't been planing in any side relief at this point.

4.  Mark board thickness on each side and plane playing surface down to marks with correct curvature and scoop (saving final playing surface work for after board is glued)

5. EDIT I might as well add that the hollow on bottom of free end of board needs to be extended towards neck root and shaped to specs before gluing.

6.  Align and glue board to neck with the 0.5 mm overhang

7.  Shape bottom of board sides to fit neck, then top of board sides...blending in curve.  So far, I have been ignoring the free end of board.  Shaping the board at the neck root is a pain for fear of dinging the varnish.

At that point, I have some relief in the each side of the board in the neck area but none in the free end portion.  I have struggled with blending in the sides of the free ends to the relief already created in the neck area.  Do you have any advice for  getting a smooth, flowing line of relief along the entire sides of the board?  Or, what can I change in my routine to make this easier?   

Maybe I should be planing the relief of the free end right down to my scribe marks before gluing the board?

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I'm not sure I understand you correctly, but I'd plane down upper end (nut) and neck (middle of FB) area almost same width to the existing neck , just leave enough you can file and sand lightly. 

Don't worry about the middle of the neck joint. (Take down FB or neck as necessary)

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I think that no matter what, some touch up/refinishing of the neck may have to take place. I thought that when you fit a new FB, you shape the sides by blending the neck edge and the FB together?

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5 minutes ago, Nick Allen said:

I thought that when you fit a new FB, you shape the sides by blending the neck edge and the FB together?

Yes.  My question was more about blending in the side relief on the free end of the board with that created in neck area by my step #5.

ChungV, you are probably right that I need to reduce the overhang before gluing the board.  

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Really good question.  

The board is flattened and the sides are taken down on the shooting board to where the nut side is at the measurement we chose (24 or 24.5 mm+) and the body side is at the measurement of the neck, and the end is 42 mm+.  If the neck is smaller than our measurement (32mm), we will change the angle of our shooting plane blade, which is also rounded for scoop, to make the board the same width as the neck at the joint, and flaring to as close to our measurements as we can at the playing surface and still look proper.  With the center at the bridge calculated and the top shimed to account for distortion, we center the fingerboard to the centering bridge by moving the nut side of the board to and fro while keeping the body side centered on the neck. Shape the surface. Once glued, the overhanging board is blended with blade and rasp to the neck leaving 1/3 of the fingerboard clean for final scraping and sanding.   I hope that makes sense.

So to your question, plane the fingerboard to exactly the correct width at the neck heal with a little bit of flare if needed; this allows you to not touch the varnish there.  When blending the sides, make a pencil mark at 1/3 down from the playing surface and blend in facets to the neck stopping at your line. Finally, if you still need to blend more nut width, move your 1/3  line on an angle from the  “g” on the “e” up to the nut while keeping it crisp.  Scrape and sand.  From the fingerboard surface you will not be able to detect the undulations of the neck underneath, and it will feel like on piece to the player.

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One thing that can be really useful in getting to the correct width at the neck heel (and any where else) is using a scraper clamped to the bench. I put it in the bench vise, using a thick scraper, and draw the board along the scraper. You can adjust the angle of the cut by moving the scraper, and it is a much more forgiving/slow process.

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Thanks, Jerry.  

1 hour ago, Jerry Pasewicz said:

So to your question, plane the fingerboard to exactly the correct width at the neck heal with a little bit of flare if needed; this allows you to not touch the varnish there

I like that idea.  It also sounds like you finish getting the correct width and relief in the free end of the board before it is glued on (easier to do since you have established your width at neck root).  

1 hour ago, Jerry Pasewicz said:

With the center at the bridge calculated and the top shimed to account for distortion

Not sure what you mean about shimming the top to account for distortion.

1 hour ago, Jerry Pasewicz said:

Once glued, the overhanging board is blended with blade and rasp to the neck leaving 1/3 of neck clean for final scraping and sanding.

Not sure what you mean about leaving 1/3 of neck clean for scraping...

arglebargle, I need more convincing....I can't imagine a vised scraper having any more control than having the  scraper in my hands.  What am I missing?  Is the scraper just barely protruding above the vise jaws, like a plane blade?

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19 minutes ago, Brad H said:

Thanks, Jerry.  

I like that idea.  It also sounds like you finish getting the correct width and relief in the free end of the board before it is glued on (easier to do since you have established your width at neck root).  

Also, when you have the final width when gluing, it is important to have a system to keep the fingerboard from moving under clamp pressure.  I use a three wood block trick Sam Z. showed me years ago, if you do not know it I can elaborate.

Not sure what you mean about shimming the top to account for distortion.

When doing a neck reset or new fingerboard we apply shims of tape under one bridge foot (usually the bass bar side) to compensate for the top distortion and twist; otherwise, the centering bridge would lean causing the neck reset to be off of true center.

Not sure what you mean about leaving 1/3 of neck clean for scraping...

Sorry, that should read 1/3 of the fingerboard, not the neck....I will edit.

1/3 measures from the playing surface down to the line....the purpose being as the light dances off the finished neck and fingerboard it does so in a nice even way.  It is much easier to cut to a straight line when there is a line to cut to.

 

arglebargle, I need more convincing....I can't imagine a vised scraper having any more control than having the  scraper in my hands.  What am I missing?  Is the scraper just barely protruding above the vise jaws, like a plane blade?

 

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Thanks.  Sorry, but now I have to ask about the top distortion and twist - what causes these?

And, yes, I would appreciate elaboration on the three wood block trick.  In the past, I have used tongue depressor sticks , notched to hold and  align the nut end of board.  I have also tried Jacob's method of gluing the board in phases (removing a clamp from a board clamped in place and sliding glue in and reclamping, etc.,)

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9 minutes ago, Brad H said:

Thanks.  Sorry, but now I have to ask about the top distortion and twist - what causes these?

And, yes, I would appreciate elaboration on the three wood block trick.  In the past, I have used tongue depressor sticks , notched to hold and  align the nut end of board.  I have also tried Jacob's method of gluing the board in phases (removing a clamp from a board clamped in place and sliding glue in and reclamping, etc.,)

I will attempt to make a drawing for Sam’s fingerboard trick.

As far as distortion and twist, instruments will distort over time.  For instance, it is very common to look at a violin and see where the back arch is slightly bulged in the soundpost area.  

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I took your idea about flaring the sides of the fingerboard and spot glued a shim on the side of my plane for use with a shooting board..  It was rather hastily done but it works.

IMG_2404.JPG

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8 minutes ago, Brad H said:

I took your idea about flaring the sides of the fingerboard and spot glued a shim on the side of my plane for use with a shooting board..  It was rather hastily done but it works.

IMG_2404.JPG

Great.  However, no need for the shim.  Just use the adjustment lever at the back to reveal more of one side than the other, that way you can dial in exactly how much you need.

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5 hours ago, Brad H said:

Is the scraper just barely protruding above the vise jaws, like a plane blade?

Yes. And using the bench vise, so assuming your bench is relatively flat, you are drawing the f.b. over a flat surface against a square (if you want) cutting surface.

I'll post pictures if I find the time. Again, not for removing a lot of wood, but for finessing the final few mm into place.

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2 hours ago, Jerry Pasewicz said:

adjustment lever at the back to reveal more of one side than the other

Ahh, yes.....the old slide-the-lever-trick.   Why didn't I think of that?

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5 hours ago, arglebargle said:

I put it in the bench vise, using a thick scraper, and draw the board along the scraper.

Thanks for the explanation.   It sounds like a diy scraper plane.  I am looking forward to trying it.

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11 hours ago, Brad H said:

Thanks for the explanation.   It sounds like a diy scraper plane.  I am looking forward to trying it.

Here are some pictures.

These, or something similar. The thicker the better.

IMG_20180114_103133501_HDR.thumb.jpg.d4e294f354ff5ef4c3687f214f694fca.jpg

Squared up, you can see how you can adjust the cutting angle to get your "flare".

IMG_20180114_103201350.thumb.jpg.988f11332a05ce7a73e5d867bbbf0265.jpg

Draw the board against the cutting surface, on either side. A nice flat bench helps.

IMG_20180114_103429561.thumb.jpg.5a1c3aa2213553fa1e212a7c380147f3.jpg

The resulting shavings.

IMG_20180114_103518360.thumb.jpg.75679e14e4bef87c54a6049ad09d6ef6.jpg

 

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Looking back to the OP I think it's important to note that you can only correct the boards measurements by a MM or so and   that you are going to have to scrape, sand and repolish the neck as part of this job.

I start with the board about 2 mm oversize at each end,  straight sides and the playing surface roughly planed to shape. I  establish the center of the  board at the bridge end and move the nut end to get the board pointed where I want it. I check to see how much difference in the over hang of the board on each side, At that point I plane  the sides to spec so that the top of the board stays aligned with the bridge but I tilt the plane as needed to bring the bottom width of the board down to just over size (0.1mm)  at the neck root. If I am moving the board quite  lot I may leave slightly more or less side relief on each side by adjusting the width at the bridge end in order to disguise the correction. At this point I have the top edges of the board with a clean line from end to end and some degree of side relief according to the original neck and the bottom side of the board overlapping the neck everywhere and about o.1 mm wider than the neck at the neck heel  and what  is necessary at the nut.. I finish planing the playing side of the board down to the first sanding, plane a !0-15 degree  chamfer down the upper third of the board's edge  then glue the on the  board and an over size  nut. When glue is dry I shape the board and nut  to the neck touching only the lower third of the board's thickness using rasps, files and scrapers. Finally I finish sand the FB  playing surface then sand the neck from 150 to 600  blending the transition to the varnish as needed and blending the sides of the new board without touching the uppermost line of the sides. Finally color and polish the neck as usual and its done.

If the original neck was set well and the board removed because it was simply too thin then the new board will be perfect. If any kind of correction was done then the new board will be some sort of compromise and my job is to make it look and feel perfect. 

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Thanks, arglebargle, that gives me a clearer picture.  It does appear that one would have a lot of control with your set up.  

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1 hour ago, nathan slobodkin said:

Looking back to the OP I think it's important to note that you can only correct the boards measurements by a MM or so

Nathan, I am sensing that you thought that my original question had to do with correcting a neck that was off-centered to the bridge.  That wasn't the case.  Nonetheless, reading your post has me feeling as if I had taken the advanced course in the topic and I am not clear on a couple points.

 

2 hours ago, nathan slobodkin said:

At that point I plane  the sides to spec so that the top of the board stays aligned with the bridge but I tilt the plane as needed to bring the bottom width of the board down to just over size (0.1mm)  at the neck root.

Are you saying that the opposite sites of the board may not be symmetrical -  like this   (  )  -at this point?

Have you already finished all work to the sides of the free end of the board when you have glued it on?

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7 hours ago, Brad H said:

Nathan, I am sensing that you thought that my original question had to do with correcting a neck that was off-centered to the bridge.  That wasn't the case.  Nonetheless, reading your post has me feeling as if I had taken the advanced course in the topic and I am not clear on a couple points.

 

Are you saying that the opposite sites of the board may not be symmetrical -  like this   (  )  -at this point?

Have you already finished all work to the sides of the free end of the board when you have glued it on?

If you have to move the board over or if the original neck wasn't shaped perfectly  (very common especially on less expensive instruments) then it may be necessary to make  a variety of compromises as far as one side being slightly more curved lengthwise or having slightly different profiles. The trick is to make the profiles blend well enough that the difference is not noticeable.

As far as the edge profile of the free end of the board that should be as close as possible to the profile of the part that is glued to the neck. I plane a chamfer from one end of the board to the other before glueing on the board to give a clean even line between the edge of the board and the playing surface of the board so when you sight along the edge you see a smooth slightly concave line. The chamfer goes down close to a third the thickness of the board and starts the rounding off of the edge of the board. The lower third of the board should match the angle of the neck heel. Scraping off the ridges  between the three sections of the thickness will give a slightly radiused profile to the free end board edges  which runs right into the radius where the  board is glued to the neck. the free end edges are sanded carefully at the same time you are sanding to blend the new board to the neck. I also French polish that area or apply whatever finish is going on the neck.

Hope that helps.

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Yes, it does.   The part about chamfering the top third of the board to provide a clean, even line before gluing is what I apparently had to hear twice...got it.  Thanks!

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I might as well ask about the bottom of the free end of the board...do you plane in a relief...0.5 mm at free end?  At what stage of the process do you do this?

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5 hours ago, Brad H said:

I might as well ask about the bottom of the free end of the board...do you plane in a relief...0.5 mm at free end?  At what stage of the process do you do this?

No, not only is it not the tradition I come from, but it never made much sense to me.  Why make the part of the fingerboard thinner that is not supported by the neck? 

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5 hours ago, Brad H said:

I might as well ask about the bottom of the free end of the board...do you plane in a relief...0.5 mm at free end?  At what stage of the process do you do this?

I might do this, if fitting a wedge-shaped fingerboard to raise to the fingerboard height at the bridge end, so the bridge end doesn't appear excessively thick. I'd probably only do this though if other ways of "raising the neck projection" involved even greater compromises.

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