How to Make a Violin

Step by step instructions

by William Bartruff, Violin Maker


Unfinished violin top.If you want to make a violin (or viola for that matter), the first thing you will need is to find one to copy. Instead of copying a cheap factory violin, I recommend reproducing a violin done by the one of the great, old Italian master makers such as Antonio Stradivari (1644-1737) or Giuseppe Guarneri del Gesu (1698-1744) or any of the myriad makers working in northern Italy through the golden period of violin making (in my opinion, approximately 1560 through 1800). In this way, you will be imitating a great violin rather than a poor one.

Please see the list of what you will need for this project at the end of these instructions. Also, I have used both US customary units and metric units in this guide. Since metric units are more precise, please familiarize yourself with the difference. Also, please note that the quote symbol (") means inch which is approximately 25.4 millimeters (mm) or 2.54 centimeters (cm) and the hash symbol (#) means number.

1. Outlines and Measurements

Now that you have a violin to copy, let us begin. You will need to acquire the outlines of the body, sound holes and scroll and measurements of the entire instrument. So for the first step, get a piece of tracing paper that will give you the space you need to make your outline for the body. A 17" x 10" piece should do nicely.

Slice a 6" X in the center of the paper to ease the arch of the back through the paper and make it easier to make the outline. Place the piece of paper on a soft surface so as not to harm the violin then place the violin length wise on the paper.

Now, draw around it with a sharp #2 pencil being very careful not to let the violin move on you. If you can get someone to help hold the violin in place, it will make this step a little easier. Once you have the body outline completed, take a bit of scotch tape and tape the X shut.

Next take a piece of 10" x 10" tracing paper to use for drawing the sound holes, or f's. If the bridge is off the violin, this will facilitate the drawing. If not, take the piece of paper and cut it in two, one for each side and place over the f's lengthwise. Use a very dull #2 pencil and very lightly, with the side face of the pencil, rub over the first f until an impression is made--something like making a penny show through with the same method. Do the same to the other f to get the other image. You might ask why not just use the first f in reverse to make the second f. But usually the old Italian makers did not cut their f's uniformly. So if you want to make an exact copy, you will need both drawings.

The last drawing is of the neck and scroll. If the pegs in the scroll can be removed from one side, then you can lay the scroll side ways on a piece of paper and trace around it. If not, take measurements of every aspect and transfer to a sheet of graph paper. In either case, for the rear and front section of the scroll use a piece of tracing paper to do a rubbing much the same way as you did the f's. Only this time, wrap a strip of the paper around the scroll and do the rubbing.

Next, on a separate sheet of paper, get the measurements of the entire violin beginning with the neck. You will need to measure the width of the neck at the join of the body and at the nut where the strings travel over to enter the peg box. Next measure the height of the ribs at the neck, the C's and the saddle. If you have drawn the scroll rather than traced it, you will have all the measurements of the scroll completed; if not, measure it now. Finally, measure the length of the stop, which is the distance from near the neck to the notch in the f's where the bridge sits, allowing for the arch.

2. Rib Assembly Mold

Now that you have all your measurements, it is time to start the rib assembly or rib garland. But first, you will need to make the mold with which the ribs are shaped. Take the outline of your violin and get .007 grade translucent Mylar® large enough to make two copies of your outline. The first one will be your working template for the back and top (which we will be using later) while the second will be the template for the ribs you need in this step. Use scissors to cut out the copies, find the horizontal center on both and draw a vertical center line on each. Set aside the template for the back and top for now and draw a line 4mm inside the second to use for the mold outline. Next, cut out the center and discard the outline since we will be working with the center-not the outline.

Now you will mark the areas for the rib, the corner block insets, the neck block and the button block. For the rib, measure to the corners of the template and draw a 25mm line. For the corner block insets, measure in 15mm from the bend below the corner and draw inward. For the neck block measure 35mm on the left and 35mm on the right side of the center line and complete the inset with two 20mm vertical lines. Similarly, for the button block, measure 25mm on the left and 25mm on the right of the center line and complete the inset with two 20mm vertical lines.

Figure 01For the actual mold, use two pieces of A/C plywood--one ¾" thick, the other ½"and both 14½" long by 9" wide. Make sure they are top grade, dry and flat. On the ½" piece, use the Mylar template to draw the outline of the ribs. Now use ¾" sheet rock screws to join the two pieces of plywood together, making sure the A grade sides of the plywood face out. Also, be sure to place the screws 2 cm from the corner blocks, the neck block and the button block. Next use a band saw to cut the joined plywood pieces and form the outline with the block insets. Then, cut ¾" holes with a spade blade. Now use a file, or a disc and spindle sander to true and square the mold. Next unscrew the mold and make each of the cut outs for the blocks 1mm bigger. Put the mold back together. Please see Figure 01.

3. Ribs

Figure 02Now you are ready to make the ribs. From a piece of spruce or willow cut blanks corresponding to the corners. Please see Figure 02. Over size them by a few millimeters. Glue (always use hide glue except where indicated) them in place on the inner face only of the ¾" part of the plywood mold and secure with small C clamps. Make sure the grain is on the quarter and faces out of the mold in a perpendicular direction.

Once dry, place the Mylar drawing on the center line and line up with the outside of the mold and draw the blanks in place. Cut them out and finish with a half bastard 1" file or a spindle sander using ¾" and 1¼" drums. Make sure you continue the center line of the mold down to the upper and lower blocks. Now you are ready to attach the ribs.

Figure 03To begin the ribs, you can either cut your own from the back or use the ones that are usually provided with the back blank. If you cut your own, you can rip them on a standard band saw, using a new 3/8" blade with 8 teeth to the inch. The width of the fence should be about 2mm so that you have room for scraping and sanding. If you desire, the ribs can be sanded with a belt sander to take out the saw marks or a small flat French plane. After this, the ribs can be scraped with a flat scraper. The rib thickness should be 1.2mm and the width should be 35mm. Use a caliper to measure these thicknesses accurately. The length should match the length of the back you have cut them from. Please see Figure 03.

Figure 04Bend the ribs, composed of the C's, the upper bouts and the lower bouts, using a banding iron. Wet the ribs lightly with a spray bottle and use a heavy leather or copper strap to bend the ribs over the iron. Please see Figure 04.

Figure 05The C's should be bent and glued first. This is so that they can be beveled to receive the upper and lower bouts and create the corner of the violin. Once the ribs are dry again, use a 1" half bastard file or the drum sander to smooth them making sure the sweep out to the corner is good and square. Please see Figure 05.

Next, the upper bouts should be bent and glued to the mold. One does not have to be as accurate with the center line as the neck will be inset here. Once the upper bouts are dry, trim the corners to the bevel and make sure they are square. I recommend you use single piece ribs for the bouts since this is traditional. However, if you do not have enough rib wood for a full wrap, then joint the leading edge of the rib squarely and place on the center line of the lower block. Glue the rib to the block and then bend the rib down to attach to the corner. Repeat on opposite side.

Figure 06Now do the lower bouts in the same manner as you did the upper. Please see Figure 06. Old Italian violins usually have the ribs all going in the same direction. Only German and French violins reversed the sides. However some Italian makers would reverse the Cs to create a bit of contrast. Use your own discretion how you want them done.

Figure 07Now you are ready to put in the back linings. Unscrew the mold, pull off the thinner half and set aside. Please see Figure 07.

Figure 08Your lining wood can be of spruce or willow. It should be 7mm wide and the thickness should be 1.5 to 2mm depending on rigidity. Please see Figure 08.

Figure 09Incise the C's with a small channel that will hold the linings in place. Please see Figure 09.

Figure 10Bend the linings using the same method you used for the ribs. Now, glue and secure the linings with clothespins that have been reinforced with a rubber band wrap. Please see Figure 10. Once dry, trim to the top of the rib and bevel the inside of the lining to blend into the surface of the rib. Be sure not to nick or scrape the rib when you do this so that cracks will not develop later. The hide glue usually dries in about an hour or, if unsure, let it sit overnight.

Figure 11Make the ribs flat by rubbing them on a sanding pad. Please see Figure 11. A sanding pad can be made by gluing sandpaper to a flat piece of ¾" A/C plywood. If you want, you can glue two different grits to the plywood faces, such as 80 and 150. Set the mold aside for now.

4. Top and Back

Figure 12Take the two blanks of maple and spruce and remove any surface chips or debris and make them as flat as you can. Please see Figure 12.

Figure 13Keep a square handy to make sure the joints are square before gluing. Please see Figure 13.

Figure 14Put the blank in a wood vice and use a good plane to join the two pieces. Please see Figure 14. Make sure that the back face is always square to the edge. Also, when you hold the two pieces up to the light, the joint should be so tight that no light passes through the seam. This may take a bit of practice before you get good at it. If you are new to planing, use two practice pieces first to get the feel for it.

Place the blanks in the vice and glue with a casein glue. Titebond® works best but you can also use Elmer's®. The top and the back are the only two joints where this type of strong glue is used. Make sure when you clamp the blanks down with bar clamps that the joint stays together. It will have a tendency to splay out, so use C clamps to secure the blanks to the bar clamps. Unclamp in two hours and allow drying completely overnight.

Figure 15Once dry, remove excess glue and make sure the two sides are even and flat. Take your rib mold and line it up to the center line of the back and clamp the upper and lower blocks. If everything is square, there should be no gaps between the ribs and the back. Now scribe a line with an awl all the way around the outline. Next take a washer with a 2mm edge and place a pencil inside it and run it around the circumference of the ribs. This will give you the outline for the back. Do the same with the top. Do not forget to draw in a 20mm half moon at the upper block of the back for the neck button. Also, square off the corners with a pencil and the outer plate Mylar template. Please see Figure 15.

Figure 16Cut the back and top out on the band saw. Since the plates are at an odd angle, use a wedge of wood to make the plate flat. Be as careful as you can to follow the outline. Finish the edge with a drum and disc sander or use a rasp and file. Please see Figure 16.

Figure 17Take a meter scribe or depth scribe and scribe a line around the edge of the top and back plates to 5mm. The finished thickness will be 4mm. This gives a slight margin for error. Please see Figure 17.

Figure 18Place the plates in the holder and begin cutting a channel with a #8, 30mm gauge and mallet around the circumference of both plates. Please see Figure 18.

Figure 19Next, cut a preliminary arch in the top and back with the 30mm gauge and smooth slightly with a fishtail gauge. Please see Figure 19.

Figure 20Now, continue the arch using a #3 sweep 50mm wide blade. Please see Figure 20.

Figure 21Use the French planes indicated and begin to plane the plates down to the correct arching. Please see Figure 21. Remember that the top plate is 1mm higher to compensate for the pressure of the bridge. Also, the back is an ellipse with the high point being at the post site and the top is a flattened ellipse. You can follow the model you are copying or you can follow the guides from your drawings. The back plate is usually about 15 to 16mm and the top is 16 to 17mm at the high point. Variations can be made depending on your design. Some believe lower arching gives a brighter, more powerful sound. This is sometimes true. Though I have heard high arched violins that are equally bright. Let the wood and your design decide.

Figure 22Finish each plate with scrapers and sandpaper. Please see Figure 22. Also, make sure that there is a channel cut around the entire plate to accommodate the purfling and final edge bead. We will discuss these more after the body of the violin is assembled.

To scoop out the inside of the back, begin by setting up a jig on the drill press that has a depth gauge. First create the lower part of your gauge by screwing in a ½" by 2" flat head bolt into a 9"x 9" piece of ¾" A/C plywood. Once done, the bolt should extend through the back of the plywood by a few millimeters to give placement in the center hole of the drill table. Clamp down and set the level of the press so that the plunger goes to within 8mm of the bolt. Use a ½" bit for this purpose. Now you are ready to drill holes to remove material from the back. You do not have to worry about drilling through the back because the depth gauge should be set. Be sure that your gauge bolts do not move on you or you will end up destroying your piece! This same procedure can be done to the top as well.

There will be little dimples where the bolt has distressed the top and back. Use hot water and a rag to wipe the surfaces and allow to dry. This will raise the grain and pull out the dimples. If any dimples remain repeat or use a flexible scraper to remove. Be careful not to alter the arching in this process.

Figure 23Put the back in the holder and use the wood clips to hold the back in place. Use the same #8 gauge as you used before and with a mallet begin removing the remainder of the inner material. When most of it is removed, use a medium French plane to begin to plane the inside in preparation for doing the graduations. Please see Figure 23 and Figure 24Figure 24. These graduations are measurements which will require a caliper with millimeter increments to complete. You are essentially making a shallow, thin bowl. Use scrapers to smooth and finish the inside of the back. Sandpaper can be used if you want to get a smoother interior. Do to the top exactly what you did to the back following the graduations.

5. Assembly

Now you are ready to attach the back to the ribs. First take the ribs off the mold by using a small hammer to tap against the blocks to release the glue joint. Place your thumb against it to absorb excess shock. Do the four corner blocks first and then the upper and lower blocks. Once the garland is removed, take the excess wood off the blocks. Now prepare the back by taking a ¾" half bastard file and gently round the inside edge over. Do not go over your scribe line or round too much into the outer edge. This will be completed at the end after full assembly.

Figure 25Attach the back to the ribs by using spool clamps and C clamps with pads at the upper and lower blocks. Please see Figure 25. Use heavy, new glue for this procedure. Only three joints use this heavy glue: the back to the ribs, the neck joint and the bass bar.

Now you are ready to place the f holes and cut them out. Follow the measurements that you made from your original violin. Use a series of pencil dots to make all marks, except for the stop line. Measure down from the neck end of the top and put a mark where the stop line is and then draw a square, perpendicular line lightly across the top. Draw the left f hole from your template onto the top. Be careful and make sure that the distances for the upper hole and the notch are properly placed. These measurements are much more important than the distance to the edge. Trace the right hole being equally cautious. After you are done, hold your work up and look at it to make sure you did the placement correctly. If you are unsure, measure again, erase and redraw.

Figure 26To cut the holes out, first drill a pilot hole in the upper and lower holes of the f. These holes should be somewhat smaller than the outline itself. Use a bit with a pilot center for more accuracy. Use a jeweler's saw with a wide throat to cut the f's. Do not use a jigsaw, since you do not have the same control as with a hand held saw. Very carefully, using a jeweler's fine blade at 15 or more teeth to the inch, insert the blade through the upper hole and re-secure to the saw. Also use a piece of plywood bolted to the bench top with a 5" semi-circle cut out of it. This gives added support while you are sawing. Use a very sharp knife to cut the remainder away to the pencil mark. I suggest for the first time that you use an X-Acto® knife with a very pointed blade to get into the tight corners. This procedure is highly delicate, so take your time, do it properly, and use all the artistry at your command to do a good job. Remember these f's will stay with the violin for its life. If by chance you nick too much wood off, stop and re-glue it and wait for it to dry before proceeding. Use small jeweler's files to round and shape any bumps or circles or nicks in the f's. Please see Figure 26.

Now that you have done the f's you will need to complete the final graduations for the top. Using the caliper and a small French plane finish cutting the inside of the top to dimension and use the scrapers and sandpaper for finish. Make sure that you do not press too hard or you will split the top. If that does happen, stop what you are doing and glue the break with strong glue. Wait until dry and go again make a pencil mark where the break is and cleats can be used for holding the joint. Unfortunately, if you break the top at the bass bar line, you must throw the top away and begin the whole top again.

The bass bar is a crucial part of the violin -- it gives the rigidity to the bass side of the top and transfers sound down the length of the top. Remember that the placement of the bass bar is on the left side as you face the violin and on the right when installing. Next measure 20mm over from the center join and mark in three places up and down the top. This is the outer margin of the bass bar placement.

Figure 27To install the bass bar, take a piece of spruce with perpendicular grain and cut to 5mm in thickness and about 25mm in depth and exactly 10 inches (25.4cm) long. Measure 2 inches (5.08 cm) from the top and the bottom of the top and draw a mark. Now line up the bass bar blank along that mark and draw three more corresponding lines on the inside of the top next to the bass bar on the joint side. Do not draw a continuous line since it creates an optical illusion for the fitting of the bass bar. Next take a piece of lining material and cut four 8mm pieces to be used for cleats and glue them right on the inside marks closest to the joint. Let dry. Now you are ready to fit the bass bar. Set the bass bar next to the cleats and draw a line on the bass bar using your index finger as a guide and run your finger along the length of the top marking the bass bar as you go. This will give you the exact outline for cutting. Now use a knife or small flat French plane and cut to the line. Begin fitting the bass bar with a knife, small plane and sandpaper. Remember to keep the grain of the bass bar parallel to the top and make sure you fit it to the contour of the top perfectly. The bass bar must fit on both sides so that no light can be seen beneath it. This procedure will take a while, so do not hurry. When I first started it took me two days to fit the bass bar. Now I can do it in thirty minutes. Practice makes perfect! Please see Figure 27.

Figure 28First before applying the glue, warm the top plate and the bass bar over a hot plate until it is warm to the touch. Now apply the heavy new glue to the leading edge of the bass bar only. Put in place and secure with the C clamps. To glue the bass bar, use deep throat C clamps with a strip of heavy leather to secure in place. Please see Figure 28. Be careful not to apply too much pressure to the clamps, or it will dent the top irreparably. Allow drying overnight, in a warm room so that the glue dries slowly. Remove the clamps and if you have pressed a little too hard, and there is a bump in the top, do not panic. Use a flexible scraper and sandpaper to restore the arching. But, if you have too much of a bump that is not repairable, cut out the bass bar and start again repeating the steps above.

Trim the bass bar, but do not over cut it. Also, taper the bass bar with a knife running the length of the bass bar to make it narrower at the top. Finish with sandpaper.

Now it is time to do the upper linings. Repeat the method exactly as the ribs were done in the mold--incising the corners and securing with clothespins. When dry, trim to fit. Make sure at this point that the ribs are the proper height all the way around. Use the sanding pad to make adjustments. Be sure you always hold the body at the upper and lower blocks so that the corners do not get over sanded.

Figure 29Glue the top on the same way as you did for the back--with spool clamps--but this time use very thin glue. This joint is the only one on the violin that is intentionally weaker to facilitate later repair; if the violin is stressed, this joint will give way before a crack appears. Please see Figure 29.

Figure 30The purfling channel is done using a double scribe, a knife and a purfling pick. Place the body of the violin back in the holder. Using the purfling scribe follow the leading edge of the violin around the circumference of the top and back. Go lightly the first time, then go over a second and perhaps a third time a little heavier. At the button, use a template and draw two lines to match up to the scribe lines. Using a knife, trace around the lines to deepen. Use the pick to remove the center wood between the two lines. Please see Figure 30.

Figure 31Bend the purfling exactly the same way as you did the linings. Cut the miters in the corners before gluing. Place glue in the channel with a small brush. Do not worry about lapping the glue on the top edge because the excess glue will be wiped off with hot water when completed. Tap the purfling in with a small ball pein hammer. Let dry overnight. When dry, trim the purfling flush to the top with a 15mm #3 gauge for the upper and lower bouts and a 12mm #7 gauge for the C's. Use a scraper and sandpaper wrapped around a wine cork to finish. Please see Figure 31.

Now you are ready to turn the edges. Use a small half bastard and flat file to run along the edges and file them over. Use your index finger as a guide on the rib side so that you do not scratch the ribs.

Figure 32To start the neck, get a piece of block wood that corresponds to the flame on the back. If you are lucky enough to have taken your blanks from a full log, you will have matching wood. Draw your template along the edge of the blank. Measure on the top edge a center line and draw two 20mm parallel lines on either side of the center line. Run the blank through the band saw on the line opposite your drawing and sand flat. This will give you a square surface to cut out the neck and scroll. Please see Figure 32.

Now, cut the outline out carefully using a ¼" band saw blade with 10 teeth to the inch. Make sure that you do not cut too far into the throat of the scroll. This can be adjusted during carving. Make a new center line from the square edge and again draw two 20mm lines on either side. Cut the opposite line and sand with a belt sander or you can use a plane. Draw the rear volute of the scroll and the upper volute, using your templates. Also draw the turns of the scroll on both sides using your templates and an awl to poke holes through the template and onto the wood. Draw in with a pencil and connect the dots.

Figure 33Secure to the bench with a large C clamp. Use a back saw to make the cuts to remove the excess wood. Go only one turn around the scroll. Use a very sharp flat 3/8" firmer chisel to remove excess wood. Also use a #3, 12mm gauge and a #8, 6mm gauge to help remove wood. Once completed, do the opposite side. Use a small backsaw and do the next turns. Please see Figure 33.

Figure 34Saw the remaining turns and cut with #4, 5mm and #7, 5mm gauges. Finish with scroll scrapers and sandpaper. Cut the back of the scroll with a small #7, 5mm and a medium #7, 15mm to complete the depth. Use a knife and files to go over the top of the scroll and sandpaper to finish. A useful tip here is to take sandpaper and glue it to a strip of wood in the same contour as your small half bastard file and use for final finishing. Drill 1/8" pilot holes for the pegs. Please see Figure 34.

Figure 35Prepare the fingerboard and glue with a strip of paper underneath to the neck. Use thin glue. Once dry, plane to shape with a rabbet plane, fingerboard templates and sandpaper. Draw a center line on the fingerboard in pencil to facilitate alignment. Finish shaping the neck to size. Please see Figure 35.

Figure 36To cut mortise in the body, place in the holder and draw the measurements transferred from the neck root to the top of the body. Make a mortise using small backsaw, sharp flat chisels and knives. Make sure you line up the center line of the fingerboard to the top and also make sure the fingerboard is exactly 21mm off of the belly and 7mm at the neck root with a 7mm inset into the body. Take your time, as this procedure is as integral to the sound of the violin as the bass bar is. To glue in place, use a large C clamp and pads. Use heavy new glue, warming the joint in the same fashion as you did for the bass bar. Please see Figure 36. Dry overnight. Using a compass, draw a half moon on the button and carve down to that line. Finish the neck with sandpaper and 0000 steel wool.

Figure 37Sand and scrape the whole violin down with 400 grit sandpaper. Do not over do it, or you will change the dimensions of the overhang on the top and back. Please see Figure 37.

Figure 38Remove the fingerboard from the neck applying even pressure on the top. Keep hold of the scroll so that you apply opposite pressure. Please see Figure 38.

6. Finish

Now you are ready for finishing. Put a single coat of very thin hide glue over the whole body and scroll except for the neck region. Use your hands with water and a damp rag to smooth. Let dry and apply a coat of clear shellac. Let dry overnight and then apply spirit violin varnish in even strips to the whole violin. Use yellow as your first two coats and then whatever colors you want thereafter. Shading can be done by carefully removing layers of colored varnish. Finish with 600 sandpaper and oil or water, polishing compound, Italian pumice or rotten stone. Use precipitated chalk and mineral oil for the last polishing. Also you can use felt, cut in 4cm squares. Or you can use French polish, a rag, mineral oil, alcohol and water.

When dry, glue the fingerboard on with no paper using thin glue, and C clamps. Glue the nut in place and cut notches for the strings. Fit the pegs with a peg shaper and use a reamer to drill out the scroll to correspond to the new pegs. Go to the narrowest setting on your peg shaper so that you do not over size the peg holes at the beginning of your violin's life.

Fit the sound post inside with a 5mm spruce dowel with the grain running length wise and perpendicular to the grain of the top.

Fit the bridge using the template. Cut the bridge feet so that they are flush to the top with no gaps. Make sure the cant of the bridge is back and not forward. Cut the bridge height to correspond to the fingerboard.

Install strings in the tailpiece and the pegs, then tune. Take a bow and play away--you are done!

What you will need: