Posts Tagged ‘linings’

Beginning Two New Violins

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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. ūüôā 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. ūüôā

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

 

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The Garland

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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…. ūüôā

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.

 

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3/4-Size Violin Neck-Set

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3/4-Size Violin in Progress. Purfling and Neck-Set

Purfling first, then Neck-set

When I last posted, the fiddle looked like this:

Purfling Slot Incised

Purfling Slot incised, but not completed.

 

Installing Purfling

This next step was to go back over the incisions, cutting them to the correct depth. Then I used a purfling pick (there are many different types) to shave out the waste wood from between the incisions. The last thing I do, before installing the purfling, is to go all the way around the slot, checking the width and depth with a scrap of dry purfling. I want the fit to be snug but not tight, and deep enough that the purfling will be flush with the surface of the plate. Here is the completed slot:

Purfling slot completed

Purfling slot completed

 

I used a bending iron to shape the sections of purfling, installing the Center bout sections first, and mitering the corners to form the desired “bee-stings.” As I cut the ends of the upper and lower bout sections, I have to check and be sure that the two mating miters will form a single sharp point, shaped exactly the way I want. This takes a good deal of practice. As one of my teachers told me, “Sure, this is tough! If it was easy, everyone would be good at it!” (Funny, that seems to be true in most walks of life…) Once the purfling is all in place, dry, I can begin gluing. Here is the dry fit:

Purfling Dry-Fit

Purfling Dry-Fit

 

Next I pry up the center of each of the center-bout strips, and, using a thin palette knife, I slip hot hide glue in under the lifted purfling, then, working quickly, I push the purfling back into the slot, and drive it home using a special tool. I start at the center ans work toward both ends, so that the glue being forced from under the purfling is driven along toward the ends of the center bout purfling strips, into the mitered corners, so that it glues the ends of the upper and lower purfling strips in place, as well.

Here is the freshly glued purfling, driven as deeply as I could manage, into the slot:

Freshly Glued Purfling

Freshly Glued Purfling

 

Freshly glued Purfling Detail

Freshly glued Purfling Detail

 

The next step is to sketch in a line 40% of the distance in from the outer edge, toward the purfling. It is a faint pencil line, but it serves as a guide to show¬†me the limits to the channel…the broad trough around the edge of the violin:

Edge Crest boundaries inscribed

Edge Crest boundaries inscribed…it’s a blurry photo, but you can see the penciled lines.

 

Then I begin cutting the channel: a trough whose outer edge is the line I just inscribed, but which cuts only as deep as is necessary.

Beginning of the channel. The Edge crest is still visible.

Beginning of the channel. The Edge crest is still visible. I have just begun to cut the channel.

 

Purfling Channel Completed

Purfling Channel Completed

 

Purfling channel Detail

Purfling channel Detail

 

Neck-Set

I laid out the neck mortise, using pencil and straightedge. Then I cut the edges of the mortise, using a razor-saw, and carved the wood away to form the mortise. It is somewhat tricky (like all the jobs in lutherie), but I got it done. Once everything was perfect, I glued the neck heel into the mortise, using hot hide glue:

 

Neck-Set Front

Neck-Set Front

 

Neck-Set Side

Neck-Set Side

 

That was all I did that day. ūüôā

The next step will be to remove the mold and install the back linings to the ribs.

Thanks for looking.

 

 

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More Progress on the “Plowden-model” Violin

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More Progress: The Plowden-model looks like a violin!

Removed the Mold and Installed the Back Linings

One nice thing about this (French-style) mold is that it is easy to remove– it usually takes less than five minutes to get it out, provided I have waxed the non-glued surfaces of the mold, so there is no chance of an accidental adhesion to the ribs. I simply use a flat chisel to crack the glue loose at each block, where it is attached to the mold, and then slip my parting knife (in reality, it is an old potato knife) between the block and the mold, to make sure nothing is still adhering to the mold. After that I can slide the mold out by lifting as shown, while wiggling each individual block to make sure they are all moving evenly. The only drawback is that I have to install the back linings after the mold is removed, and the rib garland¬†is pretty fragile. In the past, I have used a two-part collapsible mold, in the italian style (centered between the front and back edges of the ribs); but it is more difficult to remove. The only real advantage is that I¬†can install all the linings while the corpus is still on the mold, and still get the mold out without too much trouble. I believe it does have a slightly greater tendency to leave the ribs slightly convex in the center, as well, and some people find that attractive. (I do too…. Perhaps I will eventually go back to using the Italian-style molds.)

Back before mold removal

Back before mold removal. You can see how thin and fragile those ribs are.

 

This time, the linings went in without a struggle, though, and the whole task took about 30-40 minutes. A few hours later, the glue had dried, and I was able to remove all the tiny spring-clamps, and get going on leveling the back of the garland, and cleaning up the interior.

Back linings installed,

Back linings installed, ready for shaping and smoothing.

 

Blocks and linings before shaping and smoothing.

Blocks and linings before shaping and smoothing. I had trimmed the front side of the blocks, and the front linings, before I installed the front plate.

 

Blocks and linings shaped, ready for scraping and smoothing.

Blocks and linings shaped, ready for scraping and smoothing. The blocks and linings are weeping willow…the bass bar is Sitka spruce.

 

Cleaning up the Interior

Cleaning the interior primarily means shaping the linings and blocks, after the mold is out of the way, but it also is a final opportunity to scrape any rough spots, and make any minuscule repairs. So, I put on my magnifying visor, and look things over very carefully. I use a knife to trim the linings so that they are triangular in cross-section, thickest at the edge, to suport the edge of the rib, but tapered so as to not restrict the vibrations of the middle of the ribs too much.

One thing I have to remember, at this point, is that it is also my “last shot” at the interior of the back plate, so, before I install it, I carefully check and scrape it, and, as a final “seal of approval”, I install my signed and numbered label, gluing it in place where it will be visible through the bass-side sound-hole. All my instruments are individually hand-crafted, and each ends up a signed and numbered original, not a mass-produced instrument. I’m really not interested in doing things the “factory” way.

 

Installing the Back Plate

I used to complete all the work on the back plate, including purfling and final edge-work before installing it on the garland. But I have recently altered my order of operations so that I purfle and do edgework after the plate is installed. This allows me to adjust the plate overhang boundaries, and make final decisions as to how I want things to look, before permanently locking the shape in place by installing the purfling.

I also used to “self-induce panic,” by spreading hot hide glue around the perimeter of the garland and plate,¬†and then frantically trying to align the edges perfectly and adjust all the (25-30) spool-clamps, etc. before the glue gelled. That was a fool’s-errand, as the glue usually gels far more quickly than I could ever get everything clamped in place. The late Sam Compton shared how he applied the glue and allowed¬†it to gel, then aligned everything at a leisurely pace, gently clamping everything in place. ¬†Afterward, he went around the perimeter with a hair-dryer, gradually warming the plates until the glue re-liquefied.¬†Finally, he tightened the clamps just enough to completely close the joints. Pretty clever.

I ended up clamping everything dry, then loosening a few clamps at a time, and slipping the hot hide-glue into the seams, using a very thin palette knife. That seems to work pretty well, and definitely eliminates stress. (His method probably is even better, but this is how I do things, for now.)

Back plate glued in place, using hot hide glue and spool clamps.

Back plate glued in place, using hot hide glue and spool clamps.

 

Label visible through f-hole.

Label visible through f-hole. The f-holes still will require quite a bit of smoothing.

Final Edge Shape and Purfling

Once the back is securely glued in place, I can trim the edges to exactly the shape I want, so that the overhang is matching the front plate, etc., and then begin purfling.

Front view: back plate has been installed and trimmed to size.

Front view: back plate has been installed and trimmed to size.

 

Back plate installed. Side view, before purfling and edgework.

Side view, before purfling and edgework.

 

Back plate installed and trimmed to size, before purfling and edgework.

Back view: before purfling and edgework.

I use the purfling marker to scribe in the double lines (except for the corners) where the purfling will be inlaid. I then draw in the corners very carefully. I have occasionally used a template for the corners, but it seems to not always work, since the corners are not always exactly the same. So I end up just making some layout marks to get the limits delineated, and then I draw the corners in, freehand.

I incise the purfling slot with a small, sharp knife, in three or more steps:

  1. The first pass with the knife is very shallow and light, only serving to deepen all the scribe marks.
  2. The second and third passes bring the purfling slot to the correct depth, and
  3. The last step is to use a purfling pick to remove all the waste wood between the paired cuts.

 

Purfling slot partially completed;

One-piece European maple back: the Purfling slot is partially completed; but still too shallow, and a little too tight.

 

Purfling slot complet

Purfling slot is completed…¬†it turned out to be a little too tight:¬†I used a tiny sharp knife to trim the tight spots, until everything fit.

I check the depth and width of the slot by inserting a small section of purfling into the slot, all the way around, until I am sure that the slot is correct. then I bend and fit the purfling strips, and make sure the fit is as exact as I can make it, terminating in the classic “bee-stings” at¬†the corners, rather than a simple “mitered corner.”

Finally, when all is as close to perfect as I can manage, I lift each section of purfling partially out of the slot, one at a time, and slip hot, thin, hide glue into the slot, using the thin palette knife again. I press the purfling all the way down to the bottom of the slot, and allow the glue to dry before beginning the final edgework.

Back purfling completed.

Back purfling completed. Channel still needs to be cut and edgework is still untouched.

 

The Channel, and Final Edgework:

I scribe a margin around the entire outer edge, usually about 1.6mm in from the outer edge. This will serve as the “limit” for the channel. I cut the channel using gouges first,then scrapers, and bringing the smooth curve up to match the scribed limit.¬†Then I file the outer edge to round in from the center of the edge of the plate up to meet the scribed margin. I true up lines using scrapers, files, and abrasives, and then I am ready for final varnish preparations.

We’ll talk about all that in the next post, and post pictures. I need to get this one wrapped up. I’ll show close-ups of the edges and corners next time. there is still a long way to go, but it is looking more encouraging. ūüôā

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Current “State of the Fiddles” report.

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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.

I¬†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.

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5-String Progress #9: Back Plate

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Five String Fiddle Progress: Back Plate

Flattening the back of the garland

After the glue was completely dry, I removed all the clamps from the linings and cleaned up the interior: that is to say, I tapered the back linings, so that they faired smoothly into the ribs, and I shaved and scraped the blocks to their final shape.

Then I rubbed the back surface of the garland (rib and block structure) on a “sanding-board” to level the back of the garland, and to ensure that the back of the neck heel was completely¬†level with the back of the garland. That way, I can fit the back plate absolutely flat against the garland, and trace the shape.

I didn’t take a picture of this procedure, this time. Here are some¬†taken when I was building a cello:

Sanding board with cello garland

Sanding board with cello garland

 

Flattening a cello garland on a sanding board.

Flattening a cello garland on a sanding board.

I make pencil-marks on the edges of the linings, ribs and blocks, all around, and scrub until the marks disappear. When all the marks are gone, the garland is flat. It gets pretty vigorous and physical, but it is quite effective.

Here is the flattened garland, ready to trace the back plate:

Flattened garland.

Flattened garland. Notice that the neck heel is dead-flat level with the back of the garland.

As you can see, the blocks are quite smooth, now, and the linings taper gently into the ribs. After this point, there will be no more changes to the interior of the corpus, except as it directly affects the back plate.

Tracing the plate

I clamped the plate to the corpus, carefully centering the glue-seam of the back plate on the centerline of the neck and the end block.

Garland centered on plate

Garland centered on the back plate

 

 

Garland clamped to the plate.

Garland clamped to the plate.

Then I traced around the garland using a ball-point pen and a flat washer whose flange is exactly 2.5 mm wide, so that my line will be 3 mm from the ribs, all around. I watch carefully to make sure the washer stays flat on the plate…they have a tendency to flip up and follow the pen. I work along the perimeter, giving several strokes to every part, so that the line will be visible against the dark wood. Notice that this procedure makes “round” corners. I will modify them before cutting them out, so that they are the correct shape.

Tracing the shape of the plate.

Tracing the shape of the plate, using a washer and a pen. (Yep, that is a Gunderson pen!)

 

And, there is the plate, almost ready to be cut out:

Traced plate, ready for cutting out.

Traced plate, almost ready for cutting out.

One thing I do, that I forgot to photograph, is that I re-shape the corners. I use a straight-edge to connect a line from the end of the rounded corner where the pen circumscribed the corner of the rib to the center glue line at the location where the purfling will cross the far end of the plate. (Or, you can just use a 30/60/90 triangle to lay out a 30-degree angle off the center glue line on the end of each corner. But I do it with the straight-edge.) Then I continue the curves of the inner bouts to connect with the straight lines I just scribed in, and the corners are complete. I use a sharp scraper to remove any ink lines that are not part of the perimeter outline, and then I really am ready to cut out the plate.

Cutting out the plate

I use a band-saw to cut within a millimeter of the line, and then use an oscillating spindle sander to perfect the edge, right up to the lines. These and my drill press are pretty much the only power tools I use, though I have occasionally used an angle-grinder with a coarse sanding disc to remove rough excess wood, on larger instruments.

I run my fingers around the edges looking for lumps, and work those out as well, using a file as needed. Here is the completed plate blank:

Plate cut out and ready for arching.

Plate cut out and ready for arching.

At this point I also sketch in the interior graduation plan–just the outline of the inside boundaries¬†of the plate, so that I know where I am going to carve. There is no reason it has to be done at this point, but it helps me remember which side was outside and which inside…and that really does matter, as the plates are vitually never exactly bilaterally symmetrical. If I forgot and arched the wrong side, the completed plate would never fit the garland (ask me how I know…).

Interior Graduation boundaries sketched on correct side.

Interior Graduation boundaries sketched on correct side.

You can see that there are numerous bark inclusions in the wood, which I will fill with matching wood…but I will wait until the arching is complete before I attempt to fill the holes, so that I do not plane away my plugs. It is unsusual to use wood with holes in it like this, but it is also unusual to use anything other than maple for a violin back. Five-string bluegrass fiddles are not burdened by the same 300+ years of tradition as violins, though, so exotic woods can be used. This wood has amazing flame and figure in it, and the plugged holes will not detract from the beauty of the wood.

Before I begin arching, I establish the edge-thickness all the way around, using a “wheel-style marking gauge“, set to 4 mm. It has a tiny sharp wheel that does the marking, and it makes¬†very cleanly scribed lines.

Edge thickness marked

Edge thickness marked on correct edge. (Notice the bark inclusion on the other edge)

Beginning arching

I used a Japanese-style pull-saw to cut the approximate height of the plate thickness on each of the corners, so as to avoid unnecessary stress on the corners while carving the arching. It looks a little odd until the arching is complete, but it avoids the possibility of breaking off a corner. I use a large, sharp gouge to reduce the edges and begin the arching; then a toothed finger plane to continue the curves until I am very close to the desired shape. at that point I will switch to a smooth, curved-sole plane and bring the arching to nearly exactly the desired shape. From that point on, a variety of scrapers will be my only shaping tools, for fear of tearing out wood along the figuring .

Here are some photos of the progress. This is very hard, difficult wood to carve, and my hands are giving out, so this is about as far as I am going tonight:

Beginning arching 1

Beginning arching: notice the saw-cut corners, and how the one has been carved almost to a normal curve.

 

Arching back plate in cradle

Different viewing angle: The cradle is thick pine, with a plywood door-skin, to secure the plate. Inside, it is cut away, so that the plate can fit arched-side down. The plywood is right at 4mm thick, same as the finished plate.

 

Continuing arching back plate

Continuing arching. Still quite a way to go, but I am getting tired.

So…that is it for today. Pretty fancy wood, isn’t it? The customer bought it in Hawaii 33 years ago, or so, and has dragged it around all these years, until he decided that he wanted a five-string fiddle. ¬†Probably the only opportunity I will ever have to make a fiddle out of curly Koa, ¬†but it is really going to be a beautiful instrument.

My hands are getting too tired to work effectively. I will try to get more done later this week.

Thanks for looking.

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Progress Report: Post #2

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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

 

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