Posts Tagged ‘ribs’

Two Bass Bars

Please share with your friends!

Two Bass Bars

How I install bass bars:

The bass bar in a violin-family instrument serves to support the bass-foot of the bridge, and the bass-side of the front plate (also called the “table” or, the “soundboard.”) Without adequate support in the proper place anong that side, the bass tones will sound quite flabby and unconvincing. The following is only a description of how install the bass-bar, not telling anyone else how it ought to be done.

We always make the bass bar of European spruce, with the grain vertical to the plate; thus, flat-sawn to the bass-bar, itself. I begin by laying out two locations, one seventh of the distance from the center seam to the widest part of the bass-side edge at both upper and lower bout. That usually translates into about 15 mm off the center, at the widest point of the lower bout and 12 mm off center for the same place in the upper bout. I strike a line through those points , checking to see if it is far enough away from the inner eye of the bass-side f-hole to actually accommodate the completed bass-bar If it is not, then I move the line over a couple of millimeters, as needed, to gain clearance at the f-hole. Then I measure 40 mm inboard along the line from the upper and lower edges of the plate, to designate the end locations for the bass bar.

I cut the bass-bar blank to length, and plane it to the appropriate thickness, then hold it on the lines I have laid out, essentially perpendicular to what will be the plane of the ribs. I use a compass, set to the maximum gap at the bottom center of the bassbar, to scribe the contour of the plate onto each side of the bass bar. (Notice that, due to the compound curves of the violin plate, the two marks will not be the same. This is important.) Once I have both sides traced in accurately, I carve away the excess wood outside the line, to follow the line as closely as I can manage. I try to achieve a straight line between the two, regardless of where the two lines go, because that will follow the complex curves of the plate.

I double-check the bass-bar against the plate, and usually it is surprisingly close to fitting, at this point. So I use a strip of the paper-gauze tape available in pharmacies, about an inch wide, to cover the layout lines I had scribed into the plate, and then proceed to chalk-fit the bass-bar on top of that tape. The tape is very thin, so that I can see the lines through it (although I do trace them again onto the tape, to make them even easier to see.) But the tape is also so thin that, if I can get a perfect fit on the tape, when I remove the tape, I will have a perfect fit on the plate, as well, and no chalk residue to remove.

The hardest thing for me to learn in chalk-fitting, was to only remove the transferred chalk and the wood immediately under it, not the whole area. Frequently the culprit in an imperfect fit is actually quite a small area, so it is counter-productive to remove too much wood.

I chalk the tape, along the layout lines, and then press the bar into place, sliding it lengthwise a few milimeters back and forth to pick up some chalk;. I plane or scrape off the high spots where the chalk transferred, then try again. When I get a more or less full transfer of chalk from tape to bass-bar, I know the fit is acceptable. Then I carefully remove the tape, and (finally) glue and clamp the bar into place. Usually, I trim the bar a little, first, so it is nearly the correct shape on the top surface, so the clamps will fit more easily.

One bass bar is complete: the other has only been trimmed to make it easier to clamp.

One bass bar is complete: the other has only been trimmed to make it easier to clamp.

 

After the glue has dried and the bar is rigidly secured, I use finger-planes to trim the bar to the size and shape I want.

Beginning with a medium-sized finger-plane.

Beginning with a medium-sized finger-plane.

 

Finishing with a small finger-plane.

Finishing with a small finger-plane.

 

Final touch-up with small plane and scrapers.

Final touch-up with small plane and scrapers. The camera angle is what is making the two bars look so different.

 

Installing the top plates

So, the next task is to complete the inner edgework, and then install the top plates on the rib garlands. I plane a tiny bevel around the edge of the plate that will face the ribs; then file it to a curve, nearly quarter-round, flush with the outer rim of the plates. Then I position the plate on the garland as precisely as possible (sometimes things seem to have moved a bit, so I have to compromise a little.) Finally, I loosen a few of the spool clamps at a time and slip hot hide glue into the joint, using a thin palette knife. I clean up all around, so as to not leave glue on the outside of the violin.

Spool-clamps.

Spool clamps can look like these, or even more simple: sections of closet rod with all-thread bolts. There are a lot of possible options.

 

Finally, the plate is fully glued and clamped, and I wait for it to dry.

Guarneri copy top plate installed with hot hide glue and spool clamps.

Guarneri copy top plate installed with hot hide glue and spool clamps.

After the top plates are installed, I trace the European Maple back plates and cut them out. Here are the two garlands with the top plates installed and the back plates cut out:

Completed Garlands with plates.

Completed Garlands with plates.

 

Next stop will be arching the back plates.

 

Thanks for looking.

 

If you found this post helpful, please share with your friends!

Beginning Two New Violins

Please share with your friends!

Beginning Two New Violins

First Things First:

I began by making sure that I had appropriate wood for both instruments: I wanted a one-piece back for the Guarneri model instrument, with deep flames sloping downward from left to right, and I wanted a heavily flamed two-piece back for the Stradivari model…both of European Maple, with ribs to match them, and European spruce tops. I had them, all right, so I bookmatched the two spruce tops, and the back for the “Titian” Strad attempt, and left them to thoroughly dry. Afterward, I visited my son’s guitar shop and used his power planer to flatten the plates, and bring them each down to the thickness I wanted for the arching height.

Prepared plates: European Maple and Spruce

Prepared plates: European Maple and Spruce

 

Working Vacation

I took a week off from work, intending to “get a lot done” on the violins, but ended up sick for most of the week. Besides, Winter is coming on, and we needed to get firewood in, so Ann and I loaded and hauled and stacked firewood for a couple of days, and I got about two good days of work on the violins. During that time, I installed blocks in the molds, shaped them to receive the ribs, thinned and bent the ribs, and installed them. Last, I installed linings, to add stiffness to the edge of the rbs, and additional gluing surface. The ribs, like the back plates, are European Maple, but the blocks and linings are willow…not sure what variety. I like weeping willow the best, because it carves and bends so nicely, but other willows work well, too, sometimes.

Guarneri form with blocks and ribs.

Guarneri form with blocks and ribs.

 

Ribs shortened

Ribs shortened

 

Adding linings.

Adding linings.

 

Linings installed, glued, and clamped.

Linings installed, glued, and clamped.

 

Then, once I had the linings in place, I trimmed the rib corners to their final shapes, and flattened the front face of garlands, after which I used the garlands themselves to trace out the shape of the top plates. Finally, I cut out the top plates and shaped them to the exact outlines I wanted, and I was ready to begin arching. I will do the same thing for the back plates later.

All four plates, both garlands, with neck blocks.

All four plates, both garlands, with neck blocks. Strad model on the right, Guarneri on the left.

 

Slow Start

I didn’t get much of anything else done, this week, as I was at work, mostly, annnd, Thursday, some fellow failed to yield on a roundabout, and totalled my wife’s car, as she was coming home from the grocery store. The roads were very wet, which may have contributed to why he was unable to stop, and why the impact spun her car around, 180 degrees, and hurled it off the road, into a field, next to the roundabout.

Ironically, she had also just gone to DMV, and had paid $193 to renew the DEQ testing, and registration, as well as filling her gas tank, to the tune of $40. So all that was wasted, too, but she is completely unhurt, for which we are deeply grateful. Guess it is time for her to get a newer car. 🙂 There was also a dented can of beans, and two squashed bananas…but I ate the bananas, and tonight we ate the beans. No loss there. 🙂

This evening, however, I got home fairly early, and I got most of the arching done on the Stradivari-model top plate, so at least that feels better, in terms of productivity. I will try to complete it tomorrow and repeat the effort on the Guarneri top plate.

I will post more pictures later.

 

Thanks for looking

 

If you found this post helpful, please share with your friends!

The Garland

Please share with your friends!

The Garland

Shaping blocks and Bending ribs:

Inner curves of corner-blocks, and both end-blocks, first

I learned to shape only the inner curves of the corner blocks, initially, as well as the outer curves of the end blocks, because if I shape both curves on each corner block, then there exists the possibility that, when I clamp the center-bout ribs in place for gluing, the tips of the blocks may deflect outward, instead of holding their respective shapes.

Also, after the c-bout ribs are glued in place, when I shape the outer curves, in preparation for receiving the upper and lower ribs, I shape the ends of the c-bout ribs at the same time, so that they simply continue the curvature of the blocks, to a feather-thin end condition, before gluing the upper and lower ribs in place. Then, when I trim the upper and lower ribs, it is easy to make the glue-lines between the c-bout ribs and the upper and lower ribs completely invisible, matching the corner of the trimmed ribs at the corners of the instrument garland.

So, here is the mold with the blocks shaped as described above:

Blocks shaped in preparation to installing certer-bout ribs.

Blocks shaped in preparation to installing certer-bout ribs.

 

Ribs are Next

When using figured wood, I have to make a determination as to which angle the figuring will follow on the instrument. I thought I could just copy whatever the Old Master (Guarneri del Gesu) had done, but, as it turns out, he used highly figured wood for the ribs, all right, but the flame (curl) in the maple went directly across the rib at nearly exactly 90 degrees, whereas mine is quite slanted. So, I have to make a decision: Will I have the curl slant “up” (north) from the back side to the front, or the other way– from front to back?

Really, I simply have to make it consistent, on both the treble and bass sides. Some makers have the slant in the C-bouts going the opposite direction from that of the upper and lower bouts. Some, also, have used a single rib across the two lower bouts, and thus had the flame slanting one way on the bass side and the other way on the treble, and then matched the center and upper bout rib curl to the lower bout rib, so that the grain was consistent all the way around, instead of being mirrored between the two sides.

That sounds good: but, in the first place, I haven’t enough rib wood to pull it off correctly; and, in the second place, it can potentially cause problems later on, if the plates shrink (they are made of wood, remember!) and the ribs have to be shortened a little, to match. If there is already a joint at the center, it is relatively easy to simply shorten each side by a millimeter or so, as needed, and re-shape the end-pin hole. But if the bottom wood is all one piece, the repairer will have to cut through that bottom rib, and establish a new center joint; so the two halves will no longer match perfectly, though it will be pretty close.

Anyway: I usually would first thin the ribs to a consistent one millimeter thickness, and then cut them to length, carefully laying them out as to location and orientation, before bending. This time, I consulted with one of my teachers, who assured me that Guarneri ribs were a little thicker. So, since the ribs came to me at 1.3 mm, I will consider that to be the ideal thickness for this particular instrument.

Ribs

Ribs for new violin (one is already on the mold.)

 

Then I can bend all the ribs, individually, and set them aside ready to be used. In the case of the C-bout ribs, I clamp them into the mold, where they will cool, and stabilize, in exactly the correct shape. Afterward, I used a small brush to slip glue into the joints, and secure the C-bout ribs permanently to the corner blocks.

First (Treble side) C-bout rib installed.

First (Bass side) C-bout rib installed.

 

Second (Bass side) C-bout rib installed.

Second (Treble side) C-bout rib installed.

 

When the glue holding the C-bout ribs had dried sufficiently, I shaped the outer curves of the corner blocks appropriately: You can see, in the  photograph, below, that the center rib-ends have been shaped along with the outer curves of the corner blocks, so that they will cleanly fair into the curves of the upper and lower ribs.

Final shape of corner blocks.

Final shape of corner blocks. C-bout ribs are shaped along with the corner blocks.

 

I then immediately installed the upper and lower ribs in their respective places. In this particular case, I chose to install the lower ribs first. After the glue dried for a few hours, I installed the upper ribs.

Lower bout ribs installed.

 

All ribs installed.

All ribs installed.

 

When the glue holding the upper and lower ribs had dried sufficiently, I trimmed the ends to the correct length, and filed them smooth. The only “end-grain” showing will be the ends of the upper and lower ribs at each of the corners. I try to make them square with the centerlines of the corner blocks, so that it gives the inpression of a “mitered”corner, but with no apparent glue-joint: the joint is exactly along the corner of the squared-off rib end. The first priority is to have the rib end at the right angle, so it will appear to be perpendicular to the plane of the garland. The next is to file them to look “square” with the corner, as I explained above. Finally, some creative scraping of the C-bout rib-ends will usually move the glue joint to be exactly on the corner of the upper or lower rib, and make it essentially invisible. This one is close:

Corner, nearly complete

Corner, nearly complete: a little more scraping will make that joint invisible.

 

Linings

The only thing left to complete the garland is to install linings on both the front and back sides. The way I have chosen to use my mold (“French” method…ribs flush to one side of the mold) precludes my adding the back linings until after I remove the mold. That is fine: I also intend to leave the mold in place until after I have set the neck, so I have quite a way to go on that step.

Not everyone installs the neck while the corpus is on the mold. I began doing it when building my first cello, and it helped so much with neck-setting that I have continued it ever since. I deliberately allow the heel to “run wild”, in terms of length (or height, depending on how you are looking at it), so that it protrudes past the back of the neck block a little bit. When all my other items (angles, measurements, etc.) are exactly correct, I glue the neck in place, and before installing the back plate, I simply trim the back of the neck-heel flush with the back of the corpus. Then the back plate fits perfectly, and I am not struggling to get that joint tight. But… I am getting ahead of myself…. 🙂

I cut strips of willow to the appropriate dimensions for linings and then plane them smooth; then bend them to fit the curves of the violin, and finally, cut them to the appropriate lengths, and install them. Willow responds very well to both bending and carving, which is why I prefer it for lining material. I can bend all the linings in just a few minutes, and they will all hold their shape until I am ready to use them.

Bent linings, ready to be cut to length and installed.

Bent linings, ready to be cut to length and installed. Willow is easy to bend: These linings all started out like the straight one in the photo.

After the corners are all dry and secure, and trimmed, I cut two small mortises in each block, to receive the linings; then cut the linings to exactly the right lengths for a tight fit. The linings serve two purposes: they strengthen the edge of the ribs, which would otherwise be quite fragile; and they triple the gluing surface area bewteen the rib garland and the plates.

When I have all the linings fitted correctly, I remove them one at a time, apply hot hide glue, re-insert the linings, and clamp them in place, using tiny spring clamps. Sometimes one or more areas are more stubborn, and require a heavier clamp. Then I use something with more authority.

Linings fitted, glued and clamped.

Linings fitted, glued and clamped.

 

So: there is the garland (rib-structure), essentially ready to use! Next time we will level the garland, and use it to trace the shape of the front plate. At some point before attaching the front plate, I will also trim the linings to a triangular cross-section, so that the inner edges taper to a thin transition, and do not add a stress-riser to the ribs. I’m not certain whether it would affect sound, but the Old Masters did it that way, so I will follow their example. The corner blocks also will be trimmed back to be fairly minimal. I will carve away the end-blocks to each be the shape of half an ellipse, but I will leave them fairly robust, for strength.

Mold with blocks, ribs and linings.

Mold with blocks, ribs and linings.

You can still see traces of ink and glue on the blocks, looking like gaps…that will all go away when I level the garland.

 

Thanks for looking.

If you found this post helpful, please share with your friends!

New Project!

Please share with your friends!

New Project!

“Pellegrina-esque?” Violoncello da spalla?

I had been pondering (glumly) what to build for the next show at Marylhurst University, and had nearly decided upon one of two “niche-market” items…either a very large “violoncello da spalla”, or an emulation of David Rivinus’s “Pellegrina.” I had spoken to Mr. Rivinus a couple of years ago, and he told me that, for years, he had encouraged other luthiers to use his design, as a partial solution for some of the “work-related injuries” associated with playing large violas…but no one took him up on it, so he just produced them himself for the rest of his lutherie career, ultimately making 100, or so, of the odd-looking instruments. They were all sold, ultimately, and he has stopped taking orders, so I considered “taking up the mantle”, so to speak, and producing instruments modelled after his work. But, as I said, that really is rather a “niche-market” viola.

The violoncello da spalla is possibly even more specialized, as, though it is strung very much like a regular violoncello (cello), it has a fifth string (E), above the standard C-G-D-A of the cello, is only 19-20″ long on the body, and is generally played off the right shoulder, so that the lower bass-side bout is under the chin, and the bowing arm comes up from underneath, so that the player is nearly as comfortable as when playing a small viola, but the sound is that of a cello or extremely large viola–take your pick. Very little classical music has been written for these instruments, so I doubt there would ever be a lot of market for them, though I would love to build them.

But! in the midst of these ponderings, I had sent one of my teachers a couple of sets of photos of two of my recent violins, and, while he was quite encouraging and positive, he took the time to give me a carefully-considered, and quite detailed critique (what a treasure!) of both instruments, telling me what changes he would want to see, when comparing my work to one of the Old Masters (Guarneri del Gesu, in particular.) So! I changed course, and figured that I have just enough time to attempt another copy of the 1735 “Plowden” Guarneri del Gesu violin, of which I already have the “The Strad” poster, with actual CT-scans of the original instrument, and exquisite photos of the outside, along with technical drawings and tables of measurements.  Game on! New Project!

Guarneri del Gesu

(Bartolomeo Giuseppe Guarneri 1698 – 1744) was a violin maker  living and working in Cremona, Italy. He was one of the sons of Giuseppe Giovanni, and, though he was not very successful in his lifetime as a luthier (having to supplement his income by other means) compared to the more famous Antonio Stradivari, some of his later instruments are highly prized today, and sell for more than perhaps the very best Stradivari violins. Currently the very highest price (undisclosed, but reportedly in excess of $15M) was paid for the 1741 “Vieuxtemps” Guarneri del Gesu, on lifetime loan to Anne Akiko Meyers. I have never attempted an instrument modelled after the “Vieuxtemps”, but I have made two or three modelled after the 1735 “Plowden.” So that is the chosen model, again.

Starting from Scratch, Again

Checking the Mold Template against the Poster CT-Scan.

Checking the Mold Template against the Poster CT-Scan…I thought it had been exact, but there were some tiny discrepancies.

 

corrections

The black-marked edges are the places I corrected next. (Not much, really, but striving for perfection, here.)

 

Strad Poster of the Plowden

These are the photos on the poster front. The poster does not want to lie flat– I store it in a mailing tube, to keep it undamaged.

 

Checking the mold.

Checking the mold against the corrected mold-template: as it turns out, the corrections were all within the areas of the blocks– the mold is fine.

 

Blocks cut and fitted

Blocks cut and fitted…notice the differing heights, marked on the ends.

 

Blocks glued in place.

Blocks glued in place. I use Titebond for this task, but nearly nothing else.

 

Block shapes, as traced from the mold template.

Block shapes, as traced from the mold template.

 

The Wood for the New Violin

This will be a one-piece back of European Maple, neck and ribs matching the back, and a two-piece front plate of European Spruce. All were obtained from International Violin Co., of Baltimore, MD.

One-piece back, neck and ribs of European Maple, front of European Spruce.

One-piece back, neck and ribs of European Maple, front of European Spruce.

That trace on the back plate was put there by the wood-source people…it does not reflect the shape of this violin at all.

So! That is the Beginning!

I will carve the inner curves of the center-bout blocks next, so that I can bend and fit the center ribs to match those curves. Afterward, I will carve the outer curves of those same blocks as well as the tail and neck blocks, before bending and fitting the upper and lower ribs.

As a precaution against accidentally gluing the ribs to the mold, I already rubbed a paraffin candle all over the edges of the mold, where the ribs will touch, so that if an accidental drop of hide-glue ends up there, it will not stick. (Been there…broke the rib, before I figured out what was amiss.)

This is as far as I am going today…I am still recovering from hernia surgery last week, and I find I still tire easily. But I’m on my way, and will try to keep you posted, with progress reports, here

Thanks for looking.

Chet Bishop

 

If you found this post helpful, please share with your friends!

Current “State of the Fiddles” report.

Please share with your friends!

Slow Progress, But Moving Along!

Scroll-carving

I spent most of Saturday working on carving the viola scroll. I am not as fast as a lot of luthiers seem to be. It takes me more than eight hours to carve a scroll, and I can’t go at it for eight hours straight, anymore, anyway. So, between the heat and my other responsibilities, this is pretty much all I got done. It is still not complete, of course, but it is looking closer to complete, and it feels encouraging, to look at it.

This is a Big Leaf Maple scroll and back, on top of a Sitka Spruce top plate. It is interesting to carve domestic maple in close proximity to European maple. They are not the same at all. The big leaf maple is much softer, and feels almost fuzzy, under the scraper. Much lighter-weight, too, and has a different ring, when I tap it. European seemsto be  superior for violins, though domestic maples seem to work fime for larger instruments (or possibly it is the lower tones involved.) This instrument will be a good “experiment” in that regard. If  this instrument is very good, then the lower tone is the issue– if it is questionable, I may repeat the experiment immediately with European Maple and see if that corrects it. If it does, then the size of the instrument may be what is the problem.

But I suspect it will be a very good viola. I have made other very small (14-7/8″ on the body) violas using the same woods, before, and they were very good. This will be the smallest I have made, using domestic woods.

Partially completed scroll for the 14

Partially completed scroll for the 14″ viola

 

Planing and flattening the plates

Actually, come to think of it, I did do a little more– I went and used my son’s tools and planed the two violin plates to appropriate thicknesses to start working them.  I was shooting for about 17mm thick, to begin with, so that my finished arching will be close to that thickness, after everything else has been carved away. Then I laid-out the shapes of the plates by tracing them from the completed garland, and cut them out at home. So, here is what the whole pile looks like today. Last week, some of the plates were still square and flat, and very thick…this week they are all the correct thicknesses, and one scroll is nearing completion.

The lines on the right-hand maple plate (the viola back) are sketching in where the carving will happen on the inside of the plate: I will carve the outside first, to get the exact arching I have planned, then carve the inside to a similar shape, to get the exact thisknesses I hope to achieve (called “graduations” because the thickness is different in different areas, and changes gradually from area to area.) Both the arching and the graduations are critical to the final resulting sound. In my opinion,  the arching is probably more important, but I can’t prove it.

do know that when I accidentally arched some of my early violins the way (I later was taught) a viola is supposed to be arched, those violins sounded like violas, in spite of everything else about them being “violin.” It was very perplexing to me, at the time, as my ear was not well-enough trained to hear the difference, and all I knew is that it was a violin! And these crazy players kept telling me it sounded like a viola! They were right! The arching was the issue that decided the character of the sound. Good learning experience.

Current State of the Fiddles

Current State of the Fiddles

The wood on the left is European maple and spruce I bought from International Violin Co., in Baltimore, MD. I have used their wood before, and it has worked well. Both have linings and blocks made of weeping willow.

As you can see, both instruments have one-piece backs, and two-piece, book-matched fronts (sometimes referred to as tops, or bellies). In both cases the ribs and necks/scrolls are of  wood matching the back plate.

I will keep you all posted.

Thanks for looking.

If you found this post helpful, please share with your friends!

Building a Double Bass: Shaping the Blocks

Please share with your friends!

Shaping the Double Bass Blocks

Lots of Wood to Move!

As you may recall from the previous post, the blocks on this upright bass were pretty huge, compared to what they needed to be, so there was really a lot of wood to remove.

Mold with blocks and ribs

Mold with blocks and ribs. Blocks are still way oversized, and the ribs are still straight. Gotta change all that.

 

“Kutzall” Tool

So! A drastic need makes for drastic measures. Ordinarily, on a smaller instrument, I would use the bandsaw and oscillating spindle sander to shape the blocks, but this  mold is reeaaalllly heavy (over-built, I think…oh, well, it will be removed and the bass will be normal), even though it is a soloist bass, so I can’t see trying to manhandle it around on my big bandsaw. The saw could handle it, but the table for the saw is not big enough to hold the mold steady, and I am not strong enough to just hold it up there by sheer strength…. So… what to do?

This tool (carbide abrasive disc) is something my wife bought for me a year ago (Christmas), but I had never used it much. It is called a “Kutzall”, and it tears away wood incredibly rapidly, without loading up, and without burning the wood. So I used it to remove the large rough sections, then used the plane to remove the torn surface, and finally, to shape the blocks:

Kutzall disc, with 5

Kutzall disc, with 5″ DeWalt angle grinder: Not for the faint of heart! Absolutely wickedly effective, but not as dangerous as the Lancelot tool.

 

Stanley #100-1/2 Squirrel-tail Plane

It was about 37 degrees, F, outside, but the sun was bright, so I worked outside.

Smoothing and shaping the corner block

Smoothing and shaping the corner blocks, using a Stanley “Squirrel-tail” #100-1/2 hand-plane.

 

The little plane is somewhat hard to control, because the curvature of the sole is so extreme, but, if it is sharp and if the blade is set for a very shallow cut, it works well.

sharp plane

It does have to be sharp! (Time to sharpen….)

 

Stanley # 100-1/2 curved-sole plane

Stanley # 100-1/2 curved-sole plane…for those of you who are unfamiliar with it.

 

stanley plane

I was able to shape the blocks pretty close to finished shape with the little plane, but there are some irregularities. I have another tool for that problem.

 

The bottom block was planed entirely with a low-angle plane (also Stanley– can’t recall what number.) but it worked very well, and the bottom block was easy…I didn’t use the grinder at all on this one. So here are all the blocks, pretty close to finished:

Bottom block planed with a small, flat-sole, low-angle plane.

Bottom block planed with a small, flat-sole, low-angle plane.

 

And, here you can see the finished blocks, ready for sanding:

All the blocks, ready for coarse-sanding.

All the blocks, ready for coarse-sanding. The small plane leaves ripples. The sanding tool should remove them all.

 

Homemade PVC Sanding Tool

As I mentioned earlier, the oscillating spindle sander I have would not be tall enough for these blocks even if I could manhandle the mold up onto the machine. So, I made this little sanding tool out of re-claimed PVC fittings from the “Habitat for Humanity Re-Store”, and spent more on the little can of PVC cement from the hardware store than I did on all the other materials…about $2.50 at the Habitat store. I used PVC cement to affix the abrasive cloth to the pipe, too, and bound it up with strips of plastic bag until the solvent outgassed and the cement was set.

PVC sanding block

Sanding block fabricated from four PVC fittings and a 2″ section of 2″ PVC pipe, with a little piece of wood for the handle grip. Comfortable, efficient, and cheap.

 

The homemade sanding tool worked extremely well for the small corner blocks, and did very smooth work. On the neck block I used it cross-grain, holding the tool parallel to the “trough” of the curvature, and sliding it up and down the curve. It worked well, there, too, just not as perfectly as on the corner blocks. All in all, it is a very satisfying tool.

Sanding corner blocks.

Sanding the corner blocks.

 

Sanding the neck block,

Sanding the neck block, I kept the block parallel to the “trough” of the curve, and pushed it up and down, across the grain to get a smooth surface.

 

Change of Plans

You may have noticed that, though I had planned to use Willow for blocks and linings, those blocks are not willow: the corner blocks and end block are all Douglas Fir, and the neck block is laid up of three layers of clear, vertical grain Sitka Spruce. It was a matter of availability. I do have willow for the linings, and, as that in my preferred wood when I have a choice, that is what I will use. It cuts easily, bends easily, and is very pleasant to work with for both linings and blocks.

I have really felt that I was “spinning my wheels” on this project. It is large enough that I feel the necessity to work outdoors whenever possible, but the weather has not cooperated very well…it rained nearly every day for the last month. In addition, I have been struggling with a cold or some such virus. Today I was cold in the house when the thermometer read 75 degrees, so that is not normal. I finally felt a little better, this evening, and went outside for the few minutes it took me to sand the blocks, but it has been cold out, so I didn’t stay long.

Ah, well, that’s life. I’m grateful to be back on the project again.

Thanks for looking.

If you found this post helpful, please share with your friends!

Progress Report: Post #2

Please share with your friends!

Five-String Fiddle Coming Along Fine!

A day off from work means a long day on Lutherie!

I got up at 5:45 AM (usually I get up at 3:45, so this was luxury), had breakfast, watered some fruit trees, checked e-mail, and got to work. I knew the outbuilding shop where my power tools are was going to get hot very rapidly today (99 deg. F predicted, I think), so I did all I could do out there while it was still cool, then worked in the basement shop for the rest of the day.

  1. I took those rough-sawn ribs and thinned them to 1mm all over, using a fixture I made for my oscillating spindle sander (one of the few power tools I use), and cut out the neck block using my small bandsaw. I have a large bandsaw for cutting up large pieces of wood, etc. That is what I used to divide the back block into the two pieces to be joined at the back center seam (next.)
  2. I then cut out the back and front plate pieces, and joined them, book-matched, so that the grain is nearly symmetrical bilaterally, both front and back. It wasn’t easy this time. I don’t know why. I use a small hand-plane to flatten the edges until they fit nearly air-tight– definitely light-tight. I have a larger plane but this wood was so wild it required a very low-angle plane, set very light, or it tears out at all the curly grain.
  3. I glued the two halves of the front plate together using hot hide glue, and, while it was drying, I cut the ribs to the correct widths and lengths for each of the six pieces, planning as best I could to get the grain to line up appropriately at all junctions.
  4. Once the front plate was dry enough to remove the clamps, I glued up the back plate, in the same manner. Some people get a great center-join using a rubbed-joint method. I have done it that way, but I am more comfortable if I add three clamps after I do the rub.
  5. While the back dried, I planed the front plate to get it more or less level across the inner face.
  6. I took the neck blank and laid out all the measurements on it, and began shaping it a little while I was waiting for other things.

About 11:00 AM I decided I was hungry, so I had a salad and some coffee, and took a picture of the work as it stood:

All the wood in progress.

All the wood in progress.

Back to Work!

  1. I drilled 1/8″ pilot-holes in the scroll block for the pegs. When I drill them early like this I can use the drill press and get the holes perpendicular to the center line. My teacher does not do them this way– he says it risks sags in the varnish, and advocates drilling after all varnishing is complete. (He is probably right, but I can never seem to drill the holes correctly by hand, so I will risk the varnish issues.) I was right about working early in the outside shop– it is really getting hot out there now.
  2. I used the small bandsaw to cut the side cheek excess wood off the pegbox, and trued up the heel where it was too long. From here on out the scroll will all be hand-work.
  3. I used the electric bending iron to bend all six ribs, as well as the front linings. I will have to make some more lining stock– this was all I had for the moment. Fortunately they are easy to make. The linings add strength to the edges of those 1mm ribs, which are otherwise extremely fragile. They also triple the gluing surface of the rib edges, so the joint between the ribs and plates are much more secure. I try to get as much done as I can while the iron is hot, and then turn it off; for one thing, it takes about 20 minutes to heat up: but also, if you forget and leave it on, and then forget it is hot, you can get a bad burn. I keep mine at about 400 degrees F.
  4. I installed the C-bout (center) ribs, and glued them in place with hot hide glue, using wine-cork clamping cauls (donated by a friend) for the small-radius upper corners and broom-handle cauls for the lower corners. (This is really going to be a pretty instrument. The wood is gorgeous. I hope it plays well.) The upper and lower surfaces are an even larger radius, so they will be clamped using a section of large wooden closet rod. Sorry I didn’t take photos of these steps. Wasn’t thinking about pictures…I was just working.

More Pictures

Violin in beginning stages

Ribs and linings bent; Center ribs installed; Upper and lower corner surfaces shaped; Scroll begun.

As you can see, the ribs sprang back quite a bit after being bent. I should have thought ahead and prepared a block to which to clamp them while they were waiting to be glued in place. I have such a block–I just didn’t expect the springback to be so severe.

Close-up photo of the Scroll start

Close-up photo of the Scroll…pretty rough-looking, at this point, but that is how they start out…at least when I carve them.

Scroll layout lines

In this photo, you can see some of the layout lines of the pegbox. The wood is so dark that the pencil lines are hard to see.

As you can see above, after the glue was dry on the center ribs, I worked the final shape on the upper and lower surfaces of the corner blocks to ready them for the upper and lower ribs. Then:

  1. I installed the upper ribs, and, while the glue was drying on those ribs,
  2. I worked some more on the scroll. At this point the simplest way to begin removing excess wood is by cutting from the sides in to very near the layout lines for the scroll volute (the back of the scroll.) I do this by clamping the neck to a work-surface (in this case a lap-board.) and carefully starting the cuts, one at a time, spiraling up the scroll from each side. Usually I can then remove the waste wood with a knife or a flat wood-carving chisel, but the grain in this wood is too wild, so I had to try to follow the cuts around the scroll with the saw, then do the final cutting with sharp gouges and small planes.
Pull-saw and clamp

Pull-saw and clamp.

Wood Removal

Wood Removal.

Meanwhile, the glue was dry enough that I could remove the clamps from the upper ribs and install the lower ribs. When the lower rib glue was dry, I installed the front linings. These little spring clamps are really handy. I got them on a sale once, at Home Depot, for about 37 cents apiece, if I remember correctly. They are just right for this sort of work, and I bought over 100 of them…cleaned ’em out at Home Depot.

Lining clamps

Ribs and linings all installed…waiting for glue to dry.

I had been working on the scroll between other tasks, so it is coming along, too, but I am getting pretty tired, so this is about as far as I expect to get tonight. Here are a few more photos:

Side view of lining clamps.

Side view of lining clamps holding the linings while the glue dries.

Linings

The glue is dry enough to hold, so I am removing the clamps. Here you can see the linings contrasted against the dark wood of the ribs.

Front linings

All front linings visible, here. They will still need to be shaped (tapered and scraped smooth) before the violin is closed up.

Difficult wood.

This is difficult wood to work, but the scroll is progressing in satisfactory manner.

Treble side of unfinished scroll.

Other side (Treble side.)

Back of unfinished scroll.

And, the back; barely begun, but you can see the Volute beginning.

And that is it for today! Too tired…gonna call it a night. It is 11:45 PM

Thanks for looking.

Chet

 

If you found this post helpful, please share with your friends!

Progress Notes on Another 5-string (post #1)

Please share with your friends!

Five String Fiddle Progress

A fellow approached me a few months back, asking whether I could build a five-string fiddle of some exotic wood which he had bought almost 33 years ago, and which he had hung onto all this time. Of course I am delighted to make an instrument that is special to a client, so I said “Sure!”

Wood

Here is the wood (Nice stuff! I can see why he hung onto it!):

The wood from which this fiddle will be built.

The wood from which this fiddle will be built.

 

The neck, back and ribs will all be cut from this block. Actually there will be a fair amount left over, so I will try to use it in an efficient manner so that he can use the scraps for something nice, too. The front plate will be spruce. The blocks and linings are willow…not sure which specific variety.

Templates–Patterns

Here is how the pattern will fit–with lots of room left over:

Wood with patterns

Plenty of extra from which to cut rib-stock.

The section from which the back plate will be cut will be sawn into two pieces, each half the thickness of the original block. The two pieces will be glued edge to edge, so that they are “bookmatched”: that is to say that the straight edge of the mold template will become the centerline of the back plate. (I will show photos of how it is done when I get to that part.) The same thing will happen with the spruce for the front plate.

Progress and Plans

The five string fiddle will be built to my usual “Oliver 5-string” Pattern. So, the first thing I needed to do was to cut the ribstock using a band-saw. (I sliced them off at 2mm thick, later to be thinned to 1mm thick before bending to shape.) I also cut willow blocks for the four corners and the two ends.

Ribs and blocks with wood and patterns

Ribs and blocks with wood and patterns

Then I needed to glue the blocks into the mold, and mark them for their outer shape. This shape will be the inside shape of the ribs, and the blocks will become a permanent portion of the finished instrument. The mold will be removed as soon as the rib structure is safely glued to the front plate (not pictured here.) Once the glue was dry, I laid the mold-template on the centerline of the blocks, and scribed around it with a pencil.

Blocks glued into the mold, and marked for shaping.

Blocks glued into the mold, and marked for shaping.

After the blocks were marked, I was ready to begin shaping them. I really only want the center curves shaped to their final profile: the rest of the corner blocks need to stay a little thick, so as to guarantee they will not deform when I am gluing and clamping the center ribs in place. I went ahead and shaped the end blocks as well, as that does not hurt anything.

C-bouts and end blocks shaped to receive ribs.

C-bouts and end blocks shaped to receive ribs.

Here’s a side view of the same thing:

Blocks and Mold, side view.

Blocks and Mold, side view.

Once the center ribs are bent to the correct shape, I will glue them to the center bout surfaces of the corner blocks, and after the glue is dry, I will shape the outer surfaces to receive the upper and lower ribs. From that point forward, it will begin to look more and more like a violin.

I will keep you posted.

Thanks for reading.

If you found this post helpful, please share with your friends!