Posts Tagged ‘hide glue’

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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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.

 

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F-holes and Purfling

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F-holes and Purfling

F-hole Layout

I had to make a new template for the f-holes of the Guarneri model. I thought that I had made one some time ago, but if I did, I guess I must have misplaced it. I measured the image on the poster, to make certain that it matched the dimensions of the technical data on the back, and it turned out to be quite accurate, so I procured a piece of thin, fairly stiff, clear plastic (also called “re-cycled blister pack” from some sort of hardware I had bought), and laid it flat on the poster, and traced the outline of the hole with a ball-point pen. Then I traced the lines with a small sharp knife, until I was able to pop the waste plastic out, leaving a very nice template.

New f-hole template.

New f-hole template.

 

I laid out the “mensur” (sometimes called “stop-length”) on the front plate, for the bridge location, then began to lay out the relative positions of the upper and lower eyes. I had the data sheet to tell me how far apart they were to be, how far off center, and how far from the outer edges of the plate. I simply pushed it this way and that, until everything was according to the data sheet, and then traced the f-hole onto the plate, using a very sharp pencil. Then I flipped the template over and repeated the process on the other side. I double-checked everything, to make sure the layout was correct, cleaned up a few details, and was ready to incise the outlines of the f-holes.

F-hole layout complete.

F-hole layout complete. Ready to incise the outlines.

 

Incising the F-hole Outlines

I am only incising the hole outlines at this point, not making any attempt to cut them out: I have found that there is always a small flaw in my archings, in that they are always a little too high at the lower end of the f-holes. The result is that, if I look at them from the edge of the plate, my f-hole outlines look like a letter “S”, laid on its side, whereas when I look at the side view of any of Stradivari’s or Guarneri’s instruments, the stem of the f-holes seem to be nearly parallel to the plane of the ribs. So, to correct this anomaly, I lay the holes out so that they are correct, looking from the front; then I incise my outlines deeply, and finally plane and scrape the “south” end of the holes until the stems look correct from the side. The front view remains unchanged, and now it looks good from the side as well. Here is a “before and after” comparison:

Side view of F-hole before correction.

Side view of an F-hole before correction.

 

Side view of F-hole after correction.

Side view of the same F-hole after correction.

 

Beginning the Purfling Slot

The tool used to mark the location and dimensions of the purfling slot is called a “purfling marker,” or, fairly commonly, a “purfling cutter.” I suppose that, because there are two sharp blades on the tool, which are carefully set to the correct distance apart for the width of the purfling slot, and the correct distance in from the edge of the plate, it probably seems logical to call it a “cutter.” But the fact is, the tool does not work well for that purpose, and it works very well for just creasing the surface of the plate, thus scribing a double line virtually all the way around the plate. Usually the corners themselves must be laid out separately, either by hand and eye, or, by using a special template. (I have done both.)

Here is the tool, viewed from the edge, so you can see the two blades. There is a pair of small set-screws that hold the position of the twin blades.

Purfling marker blades.

Purfling marker blades. The blades are set for the width of the actual purfling, and the desired distance (4 mm, in this case) from the edge of the plate.

 

Purfling marker in use.

Purfling marker in use. The rounded brass shaft is pressed tightly against the edge of the plate.

 

Once the slot is marked all the way around, and I am satisfied with the look of the corners, I begin incising the purfling slot. The first time around, I am barely deepening the lines left by the marker; essentially just “darkening” those lines. The second time around, I press a little harder, cutting a deeper path through the wood. After that, I can cut as aggressively as I need to, and not have to worry about the blade being “turned” by a hard winter-reed, and marring the plate. This practice is especially important on the front plate, which invariably of spruce: The summer grains in spruce are very soft and easy to slice. But the winter grains (or “reeds”, as they are called) are much harder, and it is very easy for a harder, winter reed to turn a blade that is trying to cut too deeply from the start. (Hard experience speaking, here.)

Lightly tracing the outlines of the purfling slot, with a thin, sharp blade.

Lightly tracing the outlines of the purfling slot with a thin, sharp blade.

 

Initial outline incised.

Initial outline lightly incised. Ready for final cuts, and removal of waste wood.

 

Picking out Waste Wood from the Purfling Slot

After cutting to the approximate depth I want the purfling slot, I use one of several tools to pick the waste wood out of the slot between the incisions: any of them could be called a purfling pick. One of them is actually a 1/16″ gouge, made by the now-defunct Millers Falls tool people (at least, if they are still in business, I have lost track of them.) One is a tool I made for myself, attempting to achieve an easier, higher-quality cut. (It’s not that great, but it works…I can’t find it, now anyway….) The third is an actual “purfling pick” made by a commercial tool-maker. (I have had other such tools, which were functional to varying degrees. Some I eventually set aside because of poor-quality steel. They wouldn’t hold an edge.) So here are photos of the two I regularly use:

Purfling picks

Top tool is a purfling pick from Howard Core Co., and the bottom one is a 1/16″ gouge made by Millers Falls Co.

 

The idea, ultimately, is to end up with a slot into which my purfling will easily fit, but with very little extra room. I want the glue to swell the wood a tiny bit, and make it fit tightly, when I glue it in place. I also want my corners to look good. There is a reason they are frequently called “bee-stings.” I want them to be sharp and clear, and pointed in the right direction.

Using the purfling groove cleaner, (AKA

Using the purfling groove cleaner, (AKA “purfling pick.”)

 

Purfling slot completed.

Purfling slot completed. The dark dot at the top is hide glue, where I repaired a “slip.”

Installing Purfling

I make certain the slot is the right width and depth, checking it with a piece of scrap purfling, then I cut and bend the purfling to fit, giving special attention to the mitered corners. Finally, I remove one section at a time, slip hot hide-glue into the slot, using a thin palette-knife, and quickly re-insert the section of purfling, using a special roller to press it to the bottom of the slot. Once I have all six (four on the back plate) sections installed, I clean up any excess glue, and set the plate aside to dry.

Checking the depth and width of the purfling slot.

Checking the depth and width of the purfling slot. I want the purfling to end up just below the surface of the plate.

 

Purfling cut, mitered, bent and inserted into the dry slot.

Purfling cut, mitered, bent and inserted into the dry slot. the top center will be removed when the neck mortise is cut.

 

Purfling glued and pressed into place using the roller.

Purfling glued in place, pressed to the bottom of the slot, using the rollers in the picture.

The back plate is prepared in exactly the same way, except that I like to make the upper and lower purfling sections in one piece on the back. On the front, the top and bottom will eventually be removed when I cut the neck and saddle mortices, so I stop the purfling near the center at the top and bottom of the front plate. In some ways, the back is easier, in that the blade does not tend to wander as easily; but the maple is just a great deal tougher, too, so it is more physically demanding.

Next time, we will (maybe) talk about the final edgework, marking the crest of the edges, and fairing the curve from the bottom of the purfling channel up onto the curvature of the arching. But perhaps carving out the interior would be more appropriate. 🙂

 

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5 String Fiddle Progress Report #6: Front Plate Installation and Purfling

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Five String Fiddle Front Plate Installation

Back to Work!

It was fun working on the Sawmill, and just as we got that done our daughter came home (from Switzerland) for a visit, so, between that and all the overtime at work (teaching print-reading classes), it has been hard to get going again, but the fiddle has been patiently waiting on the dinig room table for me to get back to work.

Installing the Front Plate

I levelled the garland by scrubbing it back and forth on a sanding board, then aligned the plate on the garland and clamped it with spool clamps. After heating up the glue, I removed a few clamps at a time and inserted the glue with a thin pallete-knife, and re-applied the clamps. In this way, I can work my way around the perimeter, accurately and easily gluing the plate in place without fear that the glue will gel before I can get the plate clamped in place.

front plate with garland

Front plate glued in place

Ready to begin Purfling

The purfling is an inlay that is partially decorative, and to some degree a protection against cracks and splits– an edge reinforcement. There are some (usually very cheap) instruments that have the purfling simply painted on, so that it only looks good, but has no other function. They are usually seen as sub-standard, though, and I will not consider making an instrument that way…so, here is the beginning point: the purfling marker. Two blades set apart by the exact thickness of the purfling to be inlaid, and the distance from the edge set, as well.

Purfling marker

Purfling marker

Some people call this a purfling cutter, but it really does not workwell if you try to use it to cut the slot. I mark the slot with this tool and then cut the slot with a sharp, thin knife. In use, the purfling marker should be held exactly perpendicular to the plate, and tightly against the plate edge.

Purfling marker in use.

Purfling marker in use: see the double lines.

The purfling marker will not complete the corners, and they are fairly critical to the overall look, so I carefully sketch them in with a very sharp pencil.

Sketching the corners

Sketching the corners

Cutting the Purfling Slot

I usually use an X-acto knife to cut the slot, and pick the center out with one of several tools made for that purpose.

Purfling tools.

Purfling tools.

The first trip around the plate it is important to go lightly but very accurately, so that I am barely deepening the marks left by the purfling marker: after that I can cut more deeply.

Incising the Purfling Slot

Incising the Purfling Slot

Cleaning the Purfling Slot

After I am satisfied that the cuts are the correct depth all the way around, I carefully pick out the center of the slot and clean the slot, using a purfling pick. I have some that I made myself, but this one was given to me by Jake Jelley, and it works very well.

Purfling Pick in Use

Purfling Pick in Use

Ready to Install Purfling

Ready to Install Purfling

Installing the Purfling

Some people make their own purfling…maybe I will try it someday, but for now, I buy mine in three-ply strips. The strips are too brittle to bend, so I use a bending iron to make them flexible and to bend them to the correct curvature for the tight corners.

Purfling strips with prepared frot plate

Purfling strips with prepared front plate

 

I try to install the C-bout purfling first, then force the mitered ends of the upper and lower bout purfling against the mitered ends of the c-bout purfling. It takes practice to get good at this: I do not claim to have “arrived”. But it does seem to be getting easier. (I read the other day that someone asked Pablo Casals why, at 93 years of age, he was still practicing the cello for three hours a day. He said, “I think I am seeing some improvement!”) (Good one, Maestro!)

C-bout Purfling installed

C-bout Purfling installed dry

Then I install the rest of the purfling strips: I want the slots to fit snugly, but not so tight that I will struggle to install them once I apply the hide glue.

Purfling installed dry.

All Purfling installed dry. Spliced in some places, but after gluing the splices will be invisible.

Gluing and Trimming the Purfling

I lift each section up out of the slot, one at a time (tilting them, so as to try to leave the mitered ends in their places), and use the palette knife to slip thin hide glue into the slot, then press the purfling back into the slot, all the way down. I use a roller made for installing the rubber trim around window screens to force the purfling all the way home. The glue squeezes its way into the mitered corners, and secured them. The plastic roller is easy to clean afterward with hot water.

Once the purfling is glued in place, I mark a line around the margin of the plate, using a compass, with the pencil set to about 1.6mm (1/16″ or so), so that I have a guide to follow as I cut the “channel” (trimming the purfling below the surface into which it has been glued.) I want the wood surface and the purfling to make a smooth curve that begins near the edge of the plate, cycles down through the purfling, and sweeps back up to join the curve of the violin plate. I carve the channel with a gouge, then scrape to complete the curves. The faint pencil guide line can be barely seen in this photo.

Trimming the purfling and cutting the channel

Trimming the purfling and cutting the channel.

And there is the finished work, ready for the next step.

Completed Purfling.

All the purfling is trimmed, the channel is cut, and the scraping is complete.

The outer edgework will be completed after I install the neck. I used to wait and install the neck last, but I eventually decided that I prefer to install the neck and fingerboard while the front plate and rib garland are still on the mold, then trim the heel of the neck to be in plane with the back of the rib garland so that the back plate can be installed last. But that is a subject for another post….

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5-String Fiddle Progress Report #5: F-holes and Bass-Bar

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F-holes and Bass-bar

F-hole Drill

We had just completed the graduation in the last post; Usually, by this point, I am beginning to see the interior of the f-holes, too, because, as you may recall, I had incised them pretty deeply. In this particular case, I could just barely see some portions. I guess they were not as deep as I thought they were.

Once the inside is complete, I finish cutting the f-holes. Many people use a jeweler’s saw, a fretsaw, or a coping saw to cut out the f-holes. I generally just use the knife, except that I do have a special tool for cutting the round upper and lower eyes. I didn’t take any photos of it this time…here is one from an earlier instrument:

f-hole drill

F-hole drill being used to cut the lower eyes on a cello.

f-hole drill and holes

F-hole drill with completed eyes and cut-out plugs.

F-holes Completed and Clean

Just getting the f-holes cut is only part of the job…they need to be clean, and smooth, and relatively symmetrical. I will keep touching them up and tweaking them until the day I begin the varnish, most likely, but here they are; close to being complete, if not completely done.

f-holes

F-holes essentially complete.

By the way, you may have noticed that on this instrument (and the last one) I purfled after installing the plates. I was taught to purfle early, but I always had trouble getting my overhang even, and my purfling parallel to the ribs. So I tried purfling after closing…works fine and looks better. Diff’rent strokes, I guess….

Bass Bar

When the f-holes are complete, and clean, I can fit the bass-bar. The bass-bar is a spruce brace supporting the bass-side of the bridge, and providing for a good sound on the low strings.

I lay out the location of the bassbar, 1/14th of the width off center, at both upper and lower bouts. It usually ends up about 15 mm off center at the lower bout and 12 mm off center at the upper bout. (Those were the exact measurements this time: the upper bout was 168mm wide and the lower was 210 mm wide. So 1/14th of each was 12mm and 15mm respectively.) When I lay the bass-bar blank along that line, the side of the blank should just about “kiss” the upper eye on the bass side. I make slight adjustments as needed to make sure it does not obstruct the f-hole at all, then scribe the line in with a flexible steel ruler and a soft pencil. The line ends 40mm from each end of the plate, so the bassbar is just under 11″ long, (and about 7mm thick where it contacts the plate, tapering to 5mm along the free edge.)

bass-bar layout

Bass-bar layout lines complete.

Chalk-Fit Trick

Then I do something a little unusual: lots of luthiers chalk-fit bass-bars…in fact, probably most of them do. I have only known one or two who can successfully “eye-ball” the thing in. But I do not like the looks of chalk-residue mixed with hide-glue, either. I can’t see the white chalk clearly enough to use it, and the others leave an ugly residue– expecially the green or blue chalks.

So… what to do? Someone, years ago (can’t recall who…probably my friend Jake Jelley), pointed out that the paper gauze tape sold in pharmacies will stick securely, you can see the line through the tape, and it holds the chalk very well. The tape (3M Micropore) is so thin and fragile that you get a very good fit, but when you take the tape off after the fit is perfect, all the chalk comes off with it. (Careful! It can pull splinters off, too!) Hey, Presto! Clean wood, and you are ready to glue in the bass bar!

Pre-Fitting the Bar

I pre-fit the bass-bar by eye, using a compass to mark the contour from both sides, then trimming with knife and plane until the fit is close.

Bass-bar pre-fit.

Bass-bar pre-fit by eye, using a knife and plane to trim the wood to a close fit. Chalk-fitting is next.

Then I apply the paper tape, darken the line on the tape as needed, and begin the chalk-fit process. It is important to learn to JUST plane or scrape away the portion of the bass bar with chalk on it, on each try. Don’t plane off whole sections…it is possible that only that one little place with the chalk was high.

paper tape for chalk fit.

There is the paper tape…you can still see my layout lines.

chalk-fitting bass-bar

Beginning chalk-fit.

chalk-fit complete

Chalk-fit complete, and tape removed. Notice the arrow on the upper end of the bar: that is to keep me from forgetting which end is which.

Final Check and Installation

I check the fit by clamping the bar in place, dry.

bass-bar dry fit

Dry fit and clamped for final check. Seems to fit acceptably…

Then I remove the clamps, and slather on the hot hide glue–carefully. I quickly re-position the bar and clamp it securely, then clean up, using hot water and a brush. The small amount of watered-down glue soaking into the wood around the bar doesn’t seem to hurt anything, so I don’t worry about it.

bass-bar glued and clamped

Bass-bar glued, clamped and brushed down with hot water.

Shaping the Bass Bar

When the glue is completely dry, I remove the clamps and shape the bar…”just so”.

sketched shape of bass-bar

The glue is dry… see the sketched-in proposed shape of the finished bass-bar. The dark area beside the bar is just a shadow, not glue.

I do not have a “scheme”, here, and I do not measure it beyond occasionally checking the center height. I am just going by feel, by eye, and by experience. I know if the bass bar is too weak, it will affect the sound of the bass string…so I err on the side of a tall bar. I am certain that many will frown upon this. I am not telling you how you should cut a bass-bar; just sharing how I handle mine.

So; I use gouges and finger-planes initially, to shape the bar, finishing up with scrapers, files, and even sandpaper. (Yes, I know…but it’s OK, honest!)

And…there’s the plate, completed and ready to install! Well…sort of….

The glue was a little too thin on one end of the bar and it popped off for about a 2″ section. So it has been re-glued and is drying.

bass-bar nearly complete

Bass-bar nearly complete. One end popped loose, and needed re-gluing.I will do a little final shaping before calling it done.

Besides, the inner edges of the plate will have to be rounded and smoothed before I can actually install it. But there are probably less than 30 minutes of work left before I can glue the front plate in place. So it’s almost done. I hope to install it tomorrow, but I have some other things to do, as well.

Some of you may wonder why I install the front plate first; I was actually taught to do the back plate first, and to install the neck last, but it finally occurred to me that I could fit the neck before installing the back plate, and before removing the mold, and get a perfect neck-set, then trim the back of the heel flush with the rib plane, and install the back last, after removing the mold and cleaning up the interior. It worked very well, so I have continued the practice. Again; different ways of doing things result from different skill-sets and different problem-solving methods. There is nothing wrong with either way. (I even knew of a fellow who set the neck before installing either plate…but I can’t see that one. On the other hand, that guy made over 1000 instruments before he died, and sold every one of them; he must have been doing something right.)

So, the next post will involve completeing the neck and fingerboard assembly, installing the front plate, and setting the neck. Could be a week away; I am going to be working a lot of overtime on my day-job, for the next several months it seems.

Later the same evening:

finished bassbar 1

Bassbar is finally complete!

bass bar side view

Side view…lighting is difficult, but you can see the profile.

Thanks for looking.

Chet

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