Archive for February, 2018

Sealer Coat

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Sealer Coat

Cleaning off the Excess Gypsum

I used scrapers, very gently, in tight corners, and very worn 400-grit abrasive paper, more aggressively, on the easily accessible areas, to remove all the loose, or overly thick areas of the gypsum pore-filler from yesterday. It took longer than I expected, but this was the result:

Front, ready for sealer.

Front, ready for sealer.

 

Side view.

Side view.

 

Back, ready for sealer.

Back, ready for sealer.

 

You can see that the grain is somewhat obscured, and the color is quite light. I am wondering whether I did not succeed in rubbing the gypsum into the wood, as thoroughly as usual. Usually, the color has been nearly chalk-white. I can see the gypsum in the wood, though, so I am going to press on with the sealer coat.

 

Sealer Coat

This time, the sealer consisted of ordinary rosin in a solution of “pure spirits of gum turpentine”.  I probably should have made it a little thinner. It was about like light syrup; so, afterward, I dipped the brush in plain turpentine, and went back over the instrument to help the stuff penetrate a little better. The turpentine will all evaporate over the next few days (I hope), leaving only the rosin, solidifying in the pores of the wood.  It is always impressive to see just how completely the gypsum disappears, under the sealer.

The back plate, with the sealer coat applied.

The back plate, with the sealer coat applied.

 

Front plate and side, with the sealer coat applied.

Front plate and side, with the sealer coat applied.

 

Different angle

Different light angle shows the curl in a more attractive mode.

 

Now What?

Until that sealer dries completely, I will have to find other things to do.  But it is hanging in a warm room, so it should dry rapidly.

After that, It will be varnish coat after varnish coat, until it it is all done. Then the final set-up can occur.

 

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Beginning of the Finish

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Beginning of the Finish

Gypsum Mineral Pore Filler

A world-class luthier in Germany (Roger Hargraves) shared this publicly…he accomplished it a little differently, in that he prepared his gypsum by hydrating plaster of paris very thoroughly, and using the carefully washed fines as his filler. I used the finely-ground gypsum available in gardening stores, stirred it into a suspension of strong coffee and ethanol (only there to keep the coffee/gypsum mix from developing mold, sitting on the shelf), and brushed and rubbed the mixture into the wood of the violin. Then I rubbed it back off, using a soft rag, getting as much as possible back off while it is still wet. The goal is that the fine particles of gypsum will plug the pores of the wood, so that the subsequent coats of varnish will not penetrate into the wood. I can’t say whether my method works anything like that of Mr. Hargraves. Perhaps someday I will try something else. But for now, that is what I do.

First, I removed the fingerboard, and did some miniscule corrections to the scroll, pegbox and button. Then I painted on the stirred-up suspension, coating everything except the handle area of the neck.

Corrected scroll, before gypsum.

Corrected scroll, before gypsum.

 

Corrected pegbox before Gypsum.

Corrected pegbox before Gypsum.

 

Gypsum mixture on the back...still wet, but already beginning to dry.

Gypsum mixture on the back…still wet, but already beginning to dry.

 

Side view with wet gypsum suspension.

Side view with wet gypsum suspension.

 

Lots of uneven coloration.

Lots of uneven coloration. I’m not certain why, and it may present a challenge during varnishing. Not my usual experience.

 

Gypsum on scroll, beginning to dry.

Gypsum on scroll, beginning to dry.

 

Gypsum on back-- dry.

Gypsum on back– dry.  Notice how the flame is obscured.

 

Side, with dry Gypsum.

Side, with dry Gypsum.

 

Front, dry.

Front, dry.

 

I’m not certain why the spruce acted the way it did. I had wetted it with coffee before, without any mishaps. I am wondering whether I somehow compressed certain areas, in re-scraping, and they responded differently. I can’t be sure. But I have enough experience with varnish that I am not worried about the outcome. (After all, it was a very old, worn instrument I was copying.) 🙂

 

What’s next?

So…the next step will be to rub off all the excess dry gypsum, and clean up any rough areas where the grain may have raised again. (I’m not really expecting any, but I will be looking for them. Then, tomorrow evening, I hope to apply the sealer that will lock in the gypsum. It is always a little astonishing to me, to see the grain and flame suddenly “pop” out and become very visible. The gypsum becomes completely transparent, and is never evident again.

 

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Final Shaping and Scraping

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Final Shaping and Scraping

The Channels and Edges

The last time I posted, the back purfling had been installed, but the back channel had not been begun, nor were the edges trimmed and rounded. I drew in the edge crest line, just as I did on the front plate, and carved the channel with a gouge, then began scraping the channel and fairing the curve of the channel up into the curves of the arching.

Beginning Channel

Beginning the channel

 

Sample corner, after preliminary scraping.

Sample corner, after gouging and preliminary scraping.

 

After I had gone over the entire instrument under a low-angle light, looking for “lumps and bumps” (any little discontinuity that will be visible under the varnish…and they all are), I wetted a cloth with black coffee, and rubbed the whole instrument down with the damp rag. This accomplishes two things: it begins to lend a very light yellow cast to the wood, and, more importantly, for now, it raises the grain, so that every little splinter that was pressed down by the scraper, instead of being severed and removed, will now stand up and be visible…easy to find and remove, using either a very sharp scraper or, eventually, a very fine abrasive. (In general, I avoid abrasives, because I am not convinced that the surface left by fine abrasives is the same as the surface left by a sharp scraper. But, as a means of smoothing between varnish coats, or just before varnishing, I feel it is viable. I also use it on the edges of the plates…especially the spruce.)

So…here is the instrument, dampened with coffee. When the coffee is dry, I will continue the smoothing and shaping process.

Coffee rubdown.

Coffee rubdown. When it dries, it will leave a pale yellow stain…very slight.

 

coffee surface

You can see the pale yellow color, and the shape of the corners. The surface actually feels rough, now, though it looks smooth.

 

Scroll with coffee dampening.

Scroll with coffee dampening. Notice the splinters on the edge of the curves.

 

Front of scroll.

Front of scroll. See how rough the wood looks…lots of scraping still to come. And maybe some abrasive smoothing.

 

Back plate with coffee stain.

Back plate with coffee stain.

 

Final Scraping of the Whole Surface

Once the coffee was completely dry, I went to one of the few places in the house where I can get a fairly dim, very low-angle light across the violin, and went over the instrument, intently searching for either rough patches or places where the smooth continuum of the arching is interrupted by a ripple, a ridge, or a bulge, etc. I want the arching to be as close to perfect as possible, and every transition from curve to curve to be flawlessly smooth.  (I have never actually achieved this level of perfection, but that remains the standard. Every time, however, after the varnish is applied, I find things I missed.)

After scraping every surface, very gently, with a sharp scraper, until all seem to be very smooth, I rub the instrument down with coffee again. Usually, this time, the grain will not raise as agressively as before, because I did not press the grain with the scrapers but just “brushed” the surface, taking off mere dust, but leaving the channels and transitions looking finished and shiny-smooth.  This is an important time to watch for anomalies of any sort, because once the varnish is applied, it is very difficult to go back and “fix” things. Several of my earlier instruments have an odd pattern of dark stripes in the upper front bass bout, following the curve of the outer edge, and adjacent to the neck. These could have been avoided by careful scraping under a low-angle light.  They remain as permanent record of my “learning curve.” (sigh…)

Here is how the instrument looks, ready to begin the finishing process:

Front plate, ready to begin finishing process

Front plate, ready to begin. (I will remove the fingerboard first.)

 

Side view

Side view.

 

Detail of Scroll.

Detail of Scroll.

 

Back view.

Back view.

 

Detail of button and neck heel.

Detail of button and neck heel.

 

Detail of Center bout, ribs and corners.

Detail of Center bout, ribs and corners.

 

As you can see, there are are a few things I will probably want to touch-up just a little more before I actually varnish, but, overall, I am satisfied that I am ready to move forward. There will always be little things I change at the last minute, but that is just my nature.

 

What’s Next?

So…the next “big” thing is to remove the fingerboard (easy to do…I only held it on there with three dots of hide glue), and then I will rub very fine gypsum mixed with coffee into the whole instrument, and rub it back off before it dries. The goal is to fill the pores, so that the varnish will not saturate the wood.

After that is dry (and it will look chalk-white), I will apply a coat of sealer (rosin dissolved in turpentine, at the moment), to lock the gypsum down, and further seal the pores. After that; varnish time!

Thanks for looking.

 

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Button and Back Purfling

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Button and Back Purfling

Trimming the Button and Heel

When I installed the back plate, the heel had been trimmed flush with the back of the garland, but the upper surface of the heel was still quite irregular, and the upper end of the button was ridiculously oversized. The excess wood made it easy for me to install a clamp, and get the back plate glued on securely. So…when I removed all the clamps, this is what it looked like:

Back plate installed; button and heel not yet trimmed.

Back plate installed; button and heel not yet trimmed.

 

Tools for completion.

Next, I will trim the button and heel, then add purfling, then scrape. These are the tools I will use.

 

Button shape.

This is roughly the shape the button will be, but a little more refined, I hope.

 

Side view of heel and butto

Side view of the heel and the button. The closeness of the camera warps the picture a little.

 

Installing the Purfling

The next thing was to scribe in the purfling slot. I used the purfling marker to scribe the double line exactly 4mm from the outer perimeter of the plate, except the corners, where I used a sharp pencil to sketch the “bee-stings” in by hand. Then I incised the lines all the way around, just barely deepening the lines, so that they are more visible, and a little easier to follow with the blade of my small knife.

Purfling slot lines lightly incised.

Purfling slot lines lightly incised.

 

Then I slice in pass after pass, trying to get the lines deep enough for the purfling I will install. I usually find that, especially on the hard maple, I have to cut the slot in two layers: the first gets about half the depth I want, and the second finishes the slot. Here is the slot at half-depth:

Purfling slot, half-depth.

It looks good, but it is not deep enough.

 

Purfling slot ready for purfling.

Purfling slot ready for purfling.

 

Back purfling installed...glue still wet.

Back purfling installed…glue still wet. 🙂

 

Front view

And the Front!

 

Back to Work!

As most of you know, I had undergone hernia surgery, just after Christmas, and had a 6″ x 8″ polypropylene mesh patch installed in my abdomen. I have been convalescing, and just this week, have finally been feeling better. So…I just received word that I will return to my work at Gunderson, Inc., tomorrow at 6AM. I think I had better call it a day, and try to get some sleep. 3:30AM comes at the same time, every morning, whether I am ready or not. I will get home sometime after 4PM, I expect. Maybe I can jump back in where I left off. 🙂

Tomorrow evening, then, I hope to complete the purfling channel and the outer edgework of both the front and back plates, and begin the final scraping in preparation for varnishing. Any little glitch, regardless of how tiny, will be very visible under the varnish. So this part has to be done with great care.

 

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Closure!

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Closure!

Leveling the Garland

Last time I posted, I had installed the back linings, shaped the blocks and linings, and was nearly ready to close the box. It looked like this:

The blocks and linings are shaped.

The blocks and linings are shaped…but the garland is not leveled, yet.

 

To the unassisted eye, the back of the garland really looked pretty flat. In fact, I had used a hand-operated abrasive tool (a Sandvik tool…they apparently went out of production, years ago…but I love the few I have) to try to level it all the way around, thinking it might be easier. But when I clamped it up, to test the plan, it was not even close to level…so, back to the sanding board!

To level the garland, I made pencil marks all around the mating surface of the garland, and then rubbed the entire structure on the abrasive surface until all the marks disappeared. Presto! Flat!

 

Installing the Back Plate

Then, while the glue was heating up, I carefully went over the perimeter and inner surface of the back plate and made sure the curves were smooth and consistent. Once I was satisfied with it, I carefully aligned the back plate on the garland, pushing and pulling a little to get the overhang even, all the way around. I clamped only at the blocks, initially, then began using a thin-bladed palette knife to insert glue into the joint. I removed the clamps at the bottom block, first, and inserted glue so that the joint between the bottom block and the back plate was fully coated, then slid the blade left and right, as far as it would go, spreading glue on the joints between ribs/linings and back plate. I quickly reapplied the clamps at the bottom block, and added more between there and the corners. Loosened the next set of clamps, and repeated the routine.

Once the entire perimeter was glued and clamped, with an extra clamp at the button-to-heel joint, I could set the whole assembly aside to dry. It is closed!  (I really like looking at that one-piece European maple back.) 🙂

Closed corpus, back view.

Closed corpus, back view.

 

Closed corpus, side view.

Closed corpus, side view.

 

Closed Corpus, Front view.

Closed corpus, front view.

I will let the glue dry overnight, then remove the clamps and trim the heel to the correct profile, trimming button to match the heel, so that they are shaped as one unit. Then I will carve the slot in the back plate for purfling, install the purfling, and, finally, prepare the whole instrument for varnishing. I hope to be ready to begin the finishing process by this weekend.

 

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Moving Toward Completion

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Moving Toward Completion

Removing the Mold

I have chosen to use the “French” method of inside-mold. Rather than have the blocks and ribs centered on the mold, as the “Italian” method entails, and which allows the maker to install the linings on both front and back sides before either removing the mold or installing a plate, the “French” method applies the blocks and ribs flush to one side, and requires mold removal before installing the second set of linings. The advantage of the “French” method is that it makes mold removal ridiculously easy and fast. The disadvantage is that, when the mold is removed, the ribs are extremely fragile while waiting for linings. I have sometimes used a two-part mold, which makes mold removal fairly easy, but allows me to install all the linings before removing the mold…but it can be a bother, too, so, for now, I have reverted to using the flush method.

To remove the mold, I brace the completed front plate tightly against my thigh, to support it and pad it, then use a sharp chisel and a light mallet to give a sharp rap to each of the joints between the mold and the blocks. I have been careful to only allow glue on the flat central surface of each block, and I also carefully waxed the areas of the mold where I did not want glue to stick (by vigorously rubbing a candle over those surfaces), so the sudden wedging action of the mallet and chisel in each joint usually pops them cleanly apart. I check each joint with my parting knife, though, to make sure they are really free, before attempting to remove the mold. Then, I simply hold the mold, with my fingers through the clamping holes, and tap on all the blocks with the handle of a chisel, and the garland slides smoothly off the mold.

I always feel a little anxious about “hammering” on the mold, so, this time, I thought perhaps I could just “trim the blocks” with a chisel, and loosen the mold that way, and avoid the mallet. You can see the cut marks on the one corner block and one end block…but that was fruitless, and I reverted to the mallet and chisel, which (as always) worked flawlessly. You can also see that, before removing the mold, I had taken the time to saw off the excess wood from the neck heel, so that it is very nearly flush with the back of the garland.

mold has been removed

The mold has been removed, but the blocks are still rough, and the linings have not been installed.

 

You can see how fragile the ribs look, without linings. So I bent a handful of linings, and installed them, using hot hide glue and small spring clamps.

Back linings installed.

Back linings installed.

 

Back of neck-heel, planed flush with the back of the garland.

Back of neck-heel, planed flush with the back of the garland.

 

After the glue for the linings was dry, I removed the clamps, and planed the edges of the linings flush with the rib edges. Then I trimmed the inside of the linings to taper into the rib surface, and shaped the blocks to their final contour. I will still clean things up a little more, before closing, but it is getting close. There was a joint that did not get quite enough glue, so I inserted more hot hide glue and clamped it securely. I will wait until tomorrow to take the clamps off and close the corpus.

In the meantime, I spent some more time scraping the back plate smooth, inside and out. It really looks about the same, so I will not post more photos. There were just some discontinuities that I wanted removed. I went ahead and shaped the inner edge of the perimeter of the back plate, too, so it is ready to be glued to the corpus.

Blocks and linings shaped and scraped.

Blocks and linings shaped and scraped.

 

Since I can’t close the box until that glue dries, and the glue will not be dry until tomorrow, I guess I will post this, and then post again, tomorrow, after I close the corpus. (Frustrating, but that’s the way things go, sometimes.)

 

Thanks for looking.

 

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Scroll, pegbox and Neck-set

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Scroll and Pegbox completion: and Neck-set

Scroll and Pegbox Completion:

When I last posted, I had just temporarily attached the fingerboard to the neck, but had not carved the pegbox, nor the fluting on the back and top of the scroll. In the past I have completed those before attaching the fingerboard, but this time I was anxious to get going, and it seemed a good idea at the time….

So…I first shaved the fingerboard sides to fairly closely match the handle portion of the neck, and then began carving the pegbox.

Carving the pegbox.

Carving the pegbox.

 

Carving complete: scraping and filing to follow.

Carving complete: scraping and filing to follow.

 

Then I could complete the outside of the pegbox, finish tapering and scraping the handle portion of the neck, and carve the fluting on the scroll. I still had the centerline I had scribed when I first cut out the scroll, so I worked from there, and tried to “color inside the lines.”

Nearing completion.

Neck is nearing completion, outside and inside of Pegbox are pretty much complete. No fluting yet.

 

Fluting nearing completion...back view.

Fluting nearing completion…back view.

 

Fluting nearing completion: front view.

Fluting nearing completion: front view. Lots of scraping left to do.

 

Neck Mortise

Before I can set the neck, I have to lay out the exact footprint of the neck heel on the centerline of the corpus, where I will cut the mortise through the ribs and into the neck-block. I have deliberately left the heel long, so that I can set it through the neck-block, and not have to worry about fitting against the back button, because I haven’t installed the back plate yet. I will trim the heel afterward, and, when I level the back of the corpus, just before installing the back plate, I will level the heel right along with the linings and blocks.

So here is how the neck mortise went:

Mortise layout

The mortise is laid out off the centerline, which you can barely see in this photo, because one top rib nearly obscured it.

 

mortise beginning

First, I removed the rib ends, and double-checked my layout lines.

 

Front plate cut out.

Then I removed the waste wood from the edge of the front plate.

 

Mortise carving

Then I began chiseling away the block wood, to open the mortise.

 

Neck-set

The mortise has to fit the neck in every respect: It has to be the right width and shape, so that the neck goes to the correct depth. (I wanted a 6mm overstand at the edge of the front plate.) It has to be the right depth so that the distance from the front edge of the nut, to the top of the front plate will be exactly 130mm. The sole of the mortise has to be flat, so as to fit tightly against the end of the neck, but at the correct angles, both laterally and fore-and-aft, so that the neck is not twisted in relation to the corpus, the centerline of the neck is in line with the centerline of the corpus, and the projection angle is either exactly right or just a shade high. I have had instruments change fairly rapidly after they have been strung at tension for a while, due to the top bulging a little as it is compressed by the string pressure, so, I deliberately set the projection angle just a tiny bit high, anticipating that it will change a bit under string tension.

Dry-fit neck-set.

Dry-fit neck-set. No glue, yet. Just the final check of all measurements and angles.

 

Dry-fit check of overstand mark and neck length mark.

Dry-fit check of overstand mark and neck length mark. Both are correct.

 

When I am finally satisfied that all is correct, I remove the neck one last time, slather the hot hide glue into the mortise, and shove the neck home for good. I quickly check all measurements, to make sure I got it in correctly. I only have a few seconds before that glue sets up permanently. Fortunately, all was still good, and I applied a single clamp to hold it until the glue dries.

Neck-set, glued, and clamped.

Neck-set, glued, and clamped.

 

What’s Next?

You can see that I have about 10mm of extra heel hanging out behind the back of the neck block. I will saw that off, nearly flush, plane it as close to flush as I dare, then, after removing the mold, installing the back linings, and trimming the linings and blocks, I will level the entire back of the corpus, including the heel, on a “sanding board.” When all is perfectly flat, I will install the back plate, and the violin will begin to take on a life of its own.

For some reason, after I close the corpus, or thereabouts, I cease to see the instruments I make as a “project I am building”, and simply see them as an instrument I am working on. I am working on a violin, at that point, not just something that will become a violin. It is a strange feeling, but it has happened on every instrument.  A student, who built his first instrument under my guidance, put it another way: as the instrument came together, he suddenly said, “This is getting real!” I knew exactly what he meant.

Next time I will remove the mold, install the back linings, shape the blocks, and maybe get this thing closed up!

 

Thanks for looking.

 

 

 

 

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Bass Bar, Fingerboard and More

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Bass Bar, Fingerboard and More

Bass Bar Completion

When I last posted, I had installed the bass bar, and left it to dry overnight. (I did remove clamps too early one time…not good.) We needed to chauffeur a family member to the airport, in the morning, but before we left, I did get the clamps off and the bass bar completed. The rest of the day was occupied with other things.

Clamps removed: Bass bar still in raw condition.

Clamps removed: Bass bar still in raw condition.

 

Bass bar shape sketched

I sketched the general shape and size I wanted the bass bar to end up.

 

Bass bar profile planed.

Then I planed the profile shape, using an Ibex plane. Notice the Sitka  Spruce color is lightening up, as I plane away the older surface wood.

 

Bass bar complete, footprint view

Bass bar complete, footprint view; after planing and scraping.

 

Profile view of completed bass bar.

Profile view of completed bass bar.

 

Front Plate Preparation and Installation

Once the bass bar was completed, I rounded the inner edge of the front plate, all the way around, to about a 2mm radius. I checked everything one last time, and then carefully fitted the completed front plate to the completed garland, exactly where it was supposed to line up. I held it in place with six spool clamps: one at each block. Double-checked everything, then began removing a single clamp, one at a time, and inserting hot hide glue not only at that block, but as far in each direction as the blade would fit between the plate and garland. Then I re-tightened that clamp and added more spool clamps, side by side, repeating the operation umtil the whole perimeter was fully glued and clamped, like this:

Garland and front plate assembled.

The completed assembly of front plate and garland. (Remember, the mold is still in there, too!)

 

After I took the clamps off (several hours later,) the whole assembly looked like this with the back and neck:

Back, neck, garland and front plate.

Back, neck, garland and front plate.

 

More Scroll Work

While the glue dried between the garland and front plate, I completed the neck carving. There are still things to do: I have not carved the volute, yet, nor even the pegbox (usually I complete it before adding the fingerboard), but I was anxious to get the fingerboard installed, so that I could set the neck sometime soon.

Completing the neck and scroll.

Completing the neck and scroll. That gauge, with the cutouts, sizes the neck, top and bottom.

 

Fingerboard Preparation and Installation:

Once I was satisfied with the neck and scroll, I decided to begin the fingerboard. I first planed it until the edges were a consistent 5 mm thick. Then I  laid out the shape of the hollowed portion underneath the fingerboard, so that I could carve it out. I wanted the hollow to end just a few millimeters from the lower end of the neck, and be about 5mm thick all over.

 

Fingerboard prep

The hollow is laid out after the fingerboard has been planed to proper thickness.

 

More fingerboard prep

I carved, planed and scraped away the ebony until the hollow was the size and shape I wanted it to be.

 

Fingerboard temporarily attached to the neck.

Fingerboard temporarily attached to the neck, with three dots of hot hide glue.

 

Temporarily attaching the fingerboard allows me to complete the shaping of the handle portion of the neck and the fingerboard together, as a unit. I will then set the neck with the fingerboard still in place, but pop the fingerboard back off while I varnish the violin.

So…that is as far as I got today, but I feel relatively satisfied with the progress.

 

Thanks for looking.

 

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More Progress: Plates and Scroll.

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More Progress: Plates and Scroll.

Completing the Back Plate

I continued planing away wood from the inside of the back plate until it was very nearly correct, then switched to scrapers, and completed the inside surface, so that it looks to be a smooth continuum of curves, transitioning without a ripple. The  plate will require no further attention until I am ready to install it. Unlike the front plate, I intend to install the purfling later, after I am completely sure how the garland will respond to having the mold removed (sometimes they can move, and change shape a little.)

Back Plate Graduation complete.

Back Plate Graduation complete.

 

Scroll Progress

I also continued working on the scroll. My hands were getting pretty tired, so I took a break from that. It is still quite rough, but, here’s how it looked at break time:

scroll beginning

Long way to go.

 

scroll progress

On the right path, but “miles to go before I sleep.”

 

Bass Bar Fitting

To fit a bass bar, I begin with a completed front plate, and lay out the position of the bass bar, so that the distance from the center to the bar, level with upper and lower bouts at maximum width, is 1/7th the full distance from centerline to the edge at those respective points. Usually, that means that the lower point will be about 15mm from the centerline and the upper one about 12mm (as it is in this case.) I lay out a line through those two points, and observe where it is, nearest to the bass-side f-hole. If it is too close, I “fudge” it away, a bit, trying not to change the angle. (The bass bar has to clear the f-hole.) Then I mark the two ends, 40mm away from the ends of the plate, and that is the place to fit the bass bar: the “footprint”, so to speak.

Bass bar position laid out.

Bass bar position laid out.

 

I use chalk to fit my bass-bars. I have never had a good enough eye, and a sure enough knife-hand to accurately fit a bass-bar without the use of chalk, though I have known master makers who regularly did so…perfectly. (Sorry… I’m not good enough for that.) On the other hand, I have had some nasty experiences with the residue of blue chalk mingling with the yellowish hide glue when installing a bass bar: it left a very ugly green stain…and it never completely came out. So…what to do? In the first place, I switched to pink chalk. If a little chalk is left, the glue will simply make it look a bit orange. (No problem.) But, I really don’t want chalk residue at all.

A friend showed me the paper “gauze” tape available in pharmacies. It is thin enough to completely conform to the surface of the plate, and  produce a good fit, and, it is slightly translucent, so I can see my layout lines through the tape, and keep the chalk on just the path of the bass bar. I first use a compass to mark the general shape of the bottom of the bass bar, and then trim it with a knife and a small plane. That gets me “in the ball-park,” so to speak. After that, it is chalk-fitting time.

The front plate is made of European spruce, but I chose Sitka spruce for the bass bar. There is quite a contrast in color between relatively fresh European spruce, and well-aged Sitka spruce. It actually made it a little difficult to see the pink chalk against the dark wood. But it worked.

Bass bar blank, knife-trimmed after tracing the shape with a compass.

Bass bar blank, knife-trimmed after tracing the shape with a compass.

 

paper gauze tape

This is the paper gauze tape I use for chalk-fitting.

 

Paper gauze tape and pink chalk

Paper gauze tape and pink chalk, ready to begin chalk-fitting.

 

Layout lines visible through the tape.

Layout lines visible through the tape.

 

Layout lines traced over on the tape, to make them more visible.

Layout lines traced over on the tape, in pencil, to make them even more visible.

 

Chalk on tape.

Chalk on tape.

 

Chalk transferred to bass bar

Chalk transferred to bass bar

 

The idea, in any chalk-fitting procedure, is to press the fitted part (being fitted) into the chalked surface to which it is being fit, then trim away only the portions where the chalk transferred. So, in the case of the bass bar, I need to press it into the chalked top plate, and then check the bottom of the bass bar blank, to see where to cut. I trim off the obvious spots, and try again. Ideally, every time I try, I will get a broader transfer of chalk. When the whole area gets a light dusting of chalk at one time, the fit is as close to perfect as I can get it. I remove the tape, wipe off any chalk residue, slather the hot hide glue onto the bottom of the bass bar, and clamp it home. On a good day, it takes me a half-hour. On a bad day? Don’t ask… 🙂  This time wasn’t bad, though.

Chalk-fitting complete; Dry-clamped to check fit.

Chalk-fitting complete; Dry-clamped to check the fit.

 

Tight fit

The fit is good!

 

Glued and clamped

Glued and clamped. 

More Scroll Progress

While the glue was drying on the bass bar, I went back to work on the scroll. It was looking verrry rough when I had to take a break, so it is nice to see it progressing better, now. There is still a lot to do. I have to excavate the pegbox, and cut the fluting in the volute. But this is as far as I am going tonight. I am glad to call it a night, and let my hands rest.

More scroll progress

More scroll progress: there is still a long way to go, but it is looking better.

 

Scroll partly complete.

Final status for tonight. Looking a lot better, and more encouraging to see.

 

I have other things to do tomorrow, so I may or may not get to work on the violin. At the very least, I expect I will be able to trim the bass bar to the shape I want it, but beyond that, I don’t know.

 

Thanks for looking.

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