Violin build real time start to finish?

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Ken Nagy
Posts: 39
Joined: Wed Jan 15, 2020 8:03 pm

Re: Violin build real time start to finish?

Post by Ken Nagy »

Yesterday I had a productive day. In 3 hours or so, I got the bass bar fit and glued, and cut the back so I can patch those 2 spots.

I had 6 clamps made for bass bars, but 2 snapped, I think it was when gluing the parallel bars on the guitar belly. I used a wood screw with a pink eraser behind it. I fit it with the belly clamped with 2 spring clamps to a piece of plywood clamped to the bench. The plywood had a square section cut out, so I set the belly so there was just enough room to fit the bar.

I have had problems a couple times with the fit. Not that I couldn't GET it to fit, but the glue up. Using HHG I would heat up the back and bar on the heat register. Then they didn't fit! Nice. This time I decided to use fish glue. It worked great. Fit it until there are chalk marks the entire length; wipe the chalk off; put a bead of glue on the bar; press in place; slide it around a bit until it wants to stay put; wipe the excess glue off; clamp overnight.

For the patches I cut a round slot out with a small gouge that I use for scroll eyes. I smoothed it up with sandpaper. Now I'll make the matching pieces, and chalk fit them, and glue them.
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Ken Nagy
Posts: 39
Joined: Wed Jan 15, 2020 8:03 pm

Re: Violin build real time start to finish?

Post by Ken Nagy »

Yesterday I trimmed the bass bar down, and drew out the scroll 2X's size. I used a technique that David Beard showed last week on maestro net. It worked pretty good for the main shape of the pegbox and first curve of the scroll, but the scroll is an odd ball with an extra half turn in it, and it looks very circular, and not so much spiral. It has a 4:5 ratio like a del Gesu, and not the 3:4 that Stradivarius and others used. I'll get it looking good, and make a couple half size copies. I'll find out where to place the peg holes too. I noticed the other day that my drill press isn't square. How nice. Isn't that a main point? The holes for locating the back and belly are on an angle. right at the purfling on the belly, and in a ways on the back. So I'll drill 1/2 way through from both sides using the same points. That should keep the holes square. I drill them before I even cut the outline.

The tap tone on the belly went up to g# with the full uncut bar. It is down to 96/280/346. The back is 82/156/312. I used a tone generator on the computer, and matched by ear. So the low mode on the belly rose more than the ring mode with the completed bass bar.

I use a simple "exponential regression?" formula to get the heights. Full height in the middle, then divide by 10/9 at 3/4, 10/9 squared at 1/2, 10/9 cubed at 1/4, and 10/9 to the fourth power. I keep the little cheat sheet I made so I don't forget.
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Ken Nagy
Posts: 39
Joined: Wed Jan 15, 2020 8:03 pm

Re: Violin build real time start to finish?

Post by Ken Nagy »

Happy New Year.

I tried to finish up a couple instruments. A baroque guitar in G needed frets tied on. I got them on, and overnight the bridge popped off. Nice.

I went to the violin that just needed to be set up. It takes longer than you think. At least for me. I've only done about a dozen, so it isn't an everyday thing for me. Getting the tailpiece in the right place. Carving the nut, saddle and bridge. This is the bridge I did. It is flat on the TP side, and curved on the neck side. After stringing it up with Warchal Karneol's, it seems that the A is muffled some compared to the others. I know it will open up some. The E seems really stiff to me. I'll have to look into what to try. The bridge can be carved more, I just need to find where to carve!

On the Padauk violin, I have the one patch done and the gum pocket patch started to give me trouble. I was fitting the patch, and it started to split when I pushed harder while chalk fitting. That was a dumb idea, wasn't it? If it was a sound post patch, most would make a form to set it in to avoid doing something stupid like that.

I mixed some fresh HHG, spread it on the offending crack, worked it in, and it seems fine. I'll glue a couple studs near the ends of where it opened up. Then I'll finish fitting the patch. Someone told me, I forget who, that Padauk doesn't have a lot of cross grain bending ability. I might put a sound post PAD in, just to keep the forces spread out over a couple grains, and not just one.

Does that sound like a good idea?

I drew out the scroll from the photo of the original, and went to Staples yesterday and had a couple 1/2 size copies made. It is much easier to draw 2X's size. The girl said she could PROBABLY do that. Really? I decided not to ask to have one of them flipped too. My old printer from 20 years ago could do both EASILY. Progress? I don't think so.
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Ken Nagy
Posts: 39
Joined: Wed Jan 15, 2020 8:03 pm

Re: Violin build real time start to finish?

Post by Ken Nagy »

I have the back about done. I need to put two small studs on; above and below the sap pocket patch. Then I'm still thinking about a pad over the sound post area. Would a linen patch sanded smooth work?

The next step is the neck. When it is done, it can be glued together.

I've been thinking about finishing it before gluing together. I usually don't have the back and belly finished; but this time they are. It would be easier to concentrate on one area, and not everything. The ribs would be much easier.

I have a new ground system that seems good, but I need to put some varnish on it to be sure that it will stick. The varnish I did on the third try on the birds-eye maple violin is kind of chippy on the belly. I haven't had that problem before. I don't think I had oil or anything on it between coats. The back and sides seem fine.

This one needs a filler. I tried plaster of Paris before, and tried it again. I don't get the rave reviews. I can't get it to do anything, and when it does sort of fill, it stays white. Not good. There are clear water based fillers that I will try. One that was recommended is from LMI, but there is another at StewMac, and I have a gift certificate. I don't know if that one is as good as the product sold at LMI or not.

It should look cool when done. Not "pretty," but cool.
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Ken Nagy
Posts: 39
Joined: Wed Jan 15, 2020 8:03 pm

Re: Violin build real time start to finish?

Post by Ken Nagy »

I put on my new 1/4" band saw blade, and cut out my neck block the other day. Then I marked out the sides of the neck and pegbox, and the first spiral around the scroll. I marked in the mortise, and put it in the vise. Using the 3/8" palm gouge from Flexcut that I use for the eye of scrolls too, and a 6mm Japanese chisel, I cut the mortise in. It took 15-20 minutes. I use the palm gouge to make a slot for the chisel to fit in, and keep digging until I get below the holes. I also make my bottom narrow, the sides are tapered. A good thing, because using the numbers from the Maggini poster, the outside walls of the pegbox are tapered too. Unfortunately, I forgot to mark the back of the nut! It's been a while since I made a scroll. So now I'll have to fix that. I clamped it on the bench with a wood screw, and sawed cuts so I could chisel out the sides. This is where it was yesterday afternoon.
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Yesterday, after Dinner, we eat about 1 PM, I started on the scroll. I cut the pegbox sides, and the first turn around. Starting with the small chisel to break away the saw cuts, and then with a 3/4" chisel to smooth it up. That took about an hour and a half.
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Then I marked the second turn, and cut them on both sides. Then I added some undercutting of the flanks, so it doesn't look so stiff. Then I marked the 3rd turn, because this one has an extra half turn on it. I only got the one side done before it was time for lunch at 5. I'll have to do the other side on the 3rd turn, and then go around evening things up. Then add the fluting around the outside, saw the taper on the neck, and work on the curve on the bottom.

Then it will be time to fit it to the ribcage.
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Ken Nagy
Posts: 39
Joined: Wed Jan 15, 2020 8:03 pm

Re: Violin build real time start to finish?

Post by Ken Nagy »

Yesterday I got the scroll roughed in. It needs cleaning up now. Counting the cutting out, roughing the mortise, and scoring the sides for the chisel, it is an 8 hour/one day scroll. I guess you could do several of them, and finish them when you needed one. I use fingernail chisels for the fluting. I guess that's what you call them.
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They are sharp, and work well as scrapers now for cleaning it all up.

It is a little dog eared, but it should clean up fine. Even so, the scraping takes as much time as the roughing. That tests my patience. "Is is good enough yet?" And I have to use the little Flexcut gouge to make a patch where I roughed the mortise into the nut area.
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Bob Francis
Posts: 534
Joined: Wed Jan 11, 2012 6:28 pm

Re: Violin build real time start to finish?

Post by Bob Francis »

Beautiful

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