Mandolin From One 2X4 (stand Too!)

This is my first Instructable. I have admired many works published on this site and I guess the "One Board Contest" got me interested and thought it was time for me to share. I chose to make a teardrop mandolin from a single 2x4x8, red cedar stud (stand too). It was fun to build and a joy to hear it play once completed. The plan was modified from an online site offering free musical instrument plans- www.harpkit.com. I hope you enjoy my Instructable.

Materials:

1- 2X4X8', Clear Red Cedar Stud

Mandolin Tuning Mechanism

Mandolin Tail Piece

Mandolin Strings

Basic woodworking tools:

Table saw, band saw, hand saw(s), planer, jointer, hand plane(s), files/rasps, drill press, chisels, clamps- lots of clamps, squares, layout tools, router, bits/cutters, sandpaper, glue, finish...

Specialty tools/equipment:

Steam box for bending wood and a bending jig for mandolin side (explained later)

I chose to use clear red cedar. It was the straightest, cleanest, and nicest grain of all the types of wood at the lumber yard. It may not be the ideal wood to make a mandolin due to how soft it is, but it was very easy to shape, sand, and finish. Also, once completed, it has a nice mellow sound. There is many websites available discussing the choice of tonal woods for instruments. I'm satisfied with my choice.

As you can see, it is one 2 X4 X 8' stud. I laid out the pieces, labeled them, and cut them to length- side 36", fret board 14", neck 16", and the soundboard (top) and back 30".

As I mentioned in the start of this Instructable, I modified plans from a set found online- www.harpkit.com. The plans are for a teardrop mandolin and the company is Musicmaker's Kits, Inc. Some of my sizes and shapes are a bit different and I did not use a curved and tapered back.

My templates were cut out of 1/16" chipboard and used both pieces of the templates for laying out parts and pieces.

The top and back are made from 1/4" strips of the 2 X 4. I cut rough strips with the bandsaw. Between cuts I re- jointed the face of the 2 X 4 to give one smooth side. Only 4 pieces were needed to glue up and make both sides. The pieces were ripped to an even width (and to get rid of the rounded corner of the stud), jointed, book-matched for a good look, glued, clamped, and planed to final thickness- 1/8".

From the piece chosen for the side, I cut it to get a quarter sawn piece 2 1/4" wide X 1/4" thick by 36" long. The piece was jointed, ripped and planed to a final size of 1 7/8" X 1/8". I wrapped the board in a wet towel for about an hour while I set up the steam box and forming jig.

The forming jig was already made from a couple years ago when I made my first mandolin (this is only my second). The jig consists a 3 pieces of plywood (2- 3/4" & 1- 1/2") glued together cut out to the shape of the side. The inner form is 1/8" smaller than the outer form to give room for the wood to fit in tightly. As you can see from the pictures, the jig is in several parts that all clamp together for the final shape.

The steam box consists of a pot of water heated over a hotplate with a tight cap funneling the steam into a 42" section of 2" pvc pipe. A few small dowel were place through the tube to support the wood to be steamed and finally a cap placed on the end. A drain hole in located below the cap to allow any water to drain and reduce any built up steam pressure.

The side board was placed in the steam box for about 20 minutes. When it came out it was hot and very flexible but would cool off quickly so I had to work fast.

You can see in the video how the side took shape and worked on the first try. My first attempt at steaming wood a few years ago was met with multiple failures. A few research missions on the internet helped me along.

The steamed side stayed clamped overnight. The following day I removed it and clamped it to hold its shape and dry throughout.

The neck needs to be built-up at the body end (the dovetail). A short piece of scrap was used.

Neck gets laid out and cut from top and side- bandsaw works great for this step.

The flexible lining is the continuous corner glue block inside the mandolin giving extra gluing surface for the side to connect with the top and back. It was cut from the excess of the side board piece. They are (2) 3/8" X 3/8" X 36" pieces with a 45 degree bevel cut on one edge. Then the pieces were cut every 1/8" apart leaving about 1/16" from the back. This was tedious. I made a jig for the bandsaw that stopped to final depth and aligned the cuts with a cut 1/8" away. As I moved the board across, I knew it was the right spot when I could see through the cut.

A lot gets done in this step along with some preparation. First, the neck needs to get cleaned up where it glues to the side and the side has to be squared off to fit together well, sandpaper and files work great. The back needs to be rough cut. Clamp the side to the neck and trace out the back. It should be very close to your original template. Rough cut the back at least 1/4" larger than the side- it will get trimmed later. Next, a tail block needs to get created. This is a block of wood glued inside the mandolin at the bottom of the instrument. It helps strengthen the bottom and gives more material to attach the tailpiece (string attachment hardware). Once the tail block is made (cut from a scrap- see pictures and template), clamp it in place. Last step before you glue it together is to fit the flexible lining. The lining should be cut to fit tightly up against the neck and follow the side in one piece to the tail block. Some minor sanding/filing may be required to get a tight fit at the ends.

Now that everything is ready, it is glue time- all at once. Get all your pieces in order and have lots of clamps and scrap blocks available to hold it all together. I started by gluing the neck to the side- laid it flat on the bench and clamped into position. Then glue the back to the side and neck. I clamped them together with a piece of 3/4" plywood underneath and scraps across the top of the sides- make sure the sides are square with the bottom and the bottom is making full contact with the side. Glue in the tail block and clamp in place. Finally, glue the lining in place and again, clamp it (2" spring clamps reached). Let it set overnight. Hopefully now the pictures make sense.

Once the glue dries, it's time to shape the neck. I clamped the neck into a pipe clamp then held that in a bench vice. I used files, rasps, and sandpaper. I drew a line down the middle of the back of the neck and just started removing the material to a smooth arch on both sides. Where the neck meets the body, I drew large arcs and swooping curves as a guide paying attention to where the neck ends (measure from top side). You are aiming for even and smooth. The top should measure a little wider than 1 1/8" where the neck meets the curve at the head and about 1 1/2" where the neck meets the side when you finish shaping.

The head of the mandolin can be left as is with the natural grain running through. I chose to add an additional feature of a piece of book matched veneer (scrap from top and/or back). I aligned two pieces of scrap 1/8" material and used the cutout of the neck template to visualize what the veneer would look like to find the best section. The pieces were glued together, sanded, and fitted to the head of the mandolin. The head of the mandolin needed to be resurfaced to accept the extra material. I created a jig to hold the head secure then routed off 1/8" of wood. This maintained the head thickness of 9/16" and created a smooth surface. A little clean up with some sandpaper and the veneer was glued on.

Once the veneer was dry, I trimmed off the excess and shaped the top to a smooth arc instead of chamfering the corners as shown in the template.

The top edge of the side also needs a lining. Once again, fit it snug from the neck to the tail block. Once it fits well, glue it in place making sure it is flush with the top of the side. I found tape held it in place well.

The top needs an additional brace to support the tension of the strings. Cut a piece about 5/16" wide X 5/8" high X width of top about 4" up from the bottom edge- see picture. Shape the brace to be flat on one side, where it glues to the top, and tapers down on both side to a dull point. Cut the ends to have a curve reducing its height to about 1/8". A couple of pieces of the lining wedges will need to be removed for it to fit well. Once it is shaped and fitted, put it aside for now- DO NOT GLUE IT IN.

Let the glued lining dry completely before you continue with the top.

Like the back, trace out the top onto the remainder of the 1/8" X 12" board. Cut it out about 1/4" larger- trim later. I put yellow masking tape over most of the top so I could write on it and read it easier. In addition, I aligned the center of the board with the centerline of the body and neck- tape board in place or lightly clamp it. The sound hole needs to be cut out now as well as locating the upper brace (previous step).

The sound hole is 2 1/8" in diameter. I used an adjustable hole cutter with a drill press. The center of the hole is placed in the centerline of the top and centered between the bridge and end of the fret board. To figure this spot, measure from the nut location, about 1/4" down from the curve of neck to head, to the end of the fret board- 10 1/8" and from the nut to the bridge- 14 1/8". If you do the math, it's 12 1/8" down from the nut. Remove top and cut hole- be careful the wood is very thin and soft.

Mark the location of the brace on the side(s). Realign top and mark location of brace. Measure sides and figure where brace fits. Try taping in place and put top in place. The top and brace should slip right into place. If not, adjust the brace. Once you have the brace set, mark its location on the backside of the top and glue it on. Make sure it is making a good glue joint- clamp in place and leave it until it is completely dry (overnight).

After the glue is dry, it's your only opportunity to put some finish on the inside of your instrument. I brushed on 2 coats of shellac. Make sure you keep the edges and lining clean where the top is going to be glued to the side. If interested in signing your mandolin, now is the time.

Break out the clamps again. Like the back, apply a good amount of glue, position top, and clamp overnight. I put a band of masking tape around the top edge in case any glue dripped.

Once the clamps are removed, both the top and back can be trimmed to size. I used a router with a flush cutting bit- go slow and be careful.

When the veneer was added to the head and the top was attached to the body, a small space was left on the neck that needed to get filled in. Cut a scrap piece of 1/8" from the top/back stock to fit in the space- glue, shape, and sand.

Making the fret board requires the most accuracy of all work on the mandolin. The frets have to be installed in an exact location so the instrument can play properly. Start by cutting and finishing the board to 1/4" thick X 2" wide X 10 1/8" long. That's the easy part!

Layout the frets by using a purchased gauge or like I did, copy them from the plans mentioned earlier. Then I covered the board with tape and marked the fret marker dots. I drilled 3/16" holes for the markers with a brad point drill bit just below the surface, about 1/16". I filled the holes with white, 2-part epoxy, scraped flush, and let dry then removed the tape. Next I set up a jig to cut the board square. It was a block of solid surface countertop material clamped on the fret board and I used an extremely fine Japanese trim saw and cut just to the edge of the teeth- about 1/3 the thickness of the board. Take your time doing this and use a hardwood. I still used the cedar for the contest but that material is way too soft.

The fretboard needs to be cut to match the neck. Clamp it onto the neck, trace out the shape, and sand smooth. The fretboard should taper from 1 1/8" to 2".

Next, the fret wire needs to be installed. I used a narrow, low wire. It is readily available from many companies online. The wire is "T" shaped with a smooth curved top and a barbed bottom side that gets hammered in. Cut the wire about 1/8" longer than the fret space. Place board on solid surface and lightly tap the wire in from one edge working your way through to other edge. A very small amount of wire will stick out on both sides. When all wires are installed, sandwich the board between 2 pieces of wood and clamp in vice (see picture) and file wire flush to board and add a small rounded edge on ends. Only push file over frets towards the board. If you pull file or file in the opposite direction, the wire may come loose.

The completed fret board just needs to be glued in place- about 1/4"-1/2" below the curve at the head of the mandolin. It should align with the sides of the neck and cover a few inches of the top. As you can see in the pictures, plenty of clamps and a layer of masking tape protected the neck from any excess glue. Now it's starting to really look like an instrument! Hang in there you're almost done.

The mandolin needs some metal hardware- the tuning mechanism and tailpiece to hold the end of the strings. Both pieces are readily available online and range from inexpensive to way out of my budget. In addition, they come in multiple finishes and styles. I went for economical and simple. Whatever you choose, they should give you the instructions/dimensions where and what size to drill the holes in the head for a proper fit.

I made a clear plastic template to layout on the holes and get a better idea of their placement.

Go ahead and attach and fit all pieces. They will be necessary for the next step.

I ran into some problems with this step. I tried to be true to the "One Board" contest and use cedar for all wood parts. After working with this wood for a few days, I realized how soft it really is. Knowing that, I tested its ability to withstand the string tension. The wood failed and the strings cut through easily- picture shows failure. So, I went ahead and made the nut and the top of the bridge out of solid surface countertop material.

The Nut (piece at top of neck positioning the strings) is only about 1/8" X 1/2" X 1 1/8" with small grooves filed in to support and position the strings. The Bridge does the same on the body of the mandolin but is a bit bigger. I chose to epoxy a piece of the plastic on top of a piece of cedar. As you can see from the pictures, it is a bit larger than the nut. With the hardware attached, a couple strings can be loosely attached and the height of the nut and bridge can be calculated.

Finishing is the time your piece seems to come alive and takes on it's own personality- don't rush it. You have worked hard and long to get to this point.

Remove all hardware and start sanding. I started with 150 grit and worked up to 400- always with the grain and whenever possible with a block supporting the sandpaper. After sanding, wipe off all dust, mask off the fret board, and apply finish. I brushed on 3 coats of amber shellac sanding with 320 between coats.

After the third coat dried overnight, I buffed with 0000 steel wool then applied a coat of furniture wax. The fret board and bridge received a coat of lemon oil to help protect them.

Almost done!

Reinstall your hardware, add the strings (local music shop should have them or online), tune, and trim strings.

I had a pile of scrap cedar and decided to make a stand for the mandolin. There are no plans or detailed description of its construction. I believe if you were capable of making the mandolin, you have the skills to create your own stand.

Hope you enjoyed my first "Instructable", thanks.