nathanguitars

April 13, 2015 · 10:16 pm

Guitar #30/5

unfinished guitar body and neck

Above you have the carved neck, with dovetail joint, stained ready for finishing. I won’t go into the carving process – suffice to say that it involves removing just right wood. It also should be symmetrical, of course. At the speed I carve it took most of a day to go from a flat blank to what you see. Before that I cut the neck joints, then glued the completed fingerboard to the neck blank. Not quite a miracle but it feels close – the neck joint was an almost perfect fit after cutting. Trial and error – many errors, too. But this time lucky! I stained the neck with ‘dark walnut’ so it would be closer in colour to the body. Then I decided to remove some of the stain in the mid section, leaving the ends dark. This looks good, a bit like a violin.

heel of neck with french polish

head with french polish

Once again I used shellac to finish the guitar. After many years of practice I’ve got it down fairly well. Basically it just gets rubbed onto the guitar with a pad soaked in shellac, with extra dabs of pure alcohol and a few drops of light oil. Add shellac, alcohol, oil by dribbling onto pad – then rub. There is a technique and lots of instruction on the web. Best tip: use clear sealer shellac, unwaxed.

top showing reflection

I don’t like filling pores, it’s messy and hardly seems worth the effort. Some pros can fill the pores using fine pumice but I never got far with that. Once I have a decent amount of finish built up I call it a day. French polish is very thin but it doesn’t have to be thick to protect the guitar. More can always be added at any time, too.

a nice tight neck joint

It didn’t require much work to fit the neck, several thin shims to fill up the oversized cavity, and one strip of blue shop cloth soaked in white glue. I pressed the neck into the body cavity and with a little pressure from a quick clamp it set in snug and tight. To ensure it was drawn down tight to the body however I put a screw into it from inside the guitar. This works better than a clamp and can be removed easily.

clamping the fingerboard – the screw in the neck block pulls the neck tight to the body

I let this dry overnight. Then I put it all together, which took me most of the day. I previously made the nut from unbleached bone, and cut the slots with string gauged files.

bone nut, string gauge ruler, and string files

I reused an old tailpiece made of thick brass plate. I polished it up first with Nevr Dull, a product I remember my Dad had around for ever in the basement. Works great on dull old brass.

brass tailpiece all shined up

Next came the bridge. I was a bit surprised to find that the bridge is taller than expected. Not much, but these things happen, as I have said before. I made a bridge blank then used a pencil on a stick to mark the line for the top of the bridge.

bridge height marking tool

Then I installed the tuners, the nut, the tailpiece and strings. More fiddling with the bridge, including finishing it, and making shallow slots for the strings. This is an iterative process in which the bridge goes on and off numerous times, involving much laborious turning of the tuning heads, and often broken strings. But this time none broke. However I did find numerous buzzes, which required replacement of several frets. There are still some very minor buzzes but for now I will wait and see how it settles down before attempting more adjustments. I used the adjustable truss rod to flatten the neck a tiny bit.

the finished guitar #30

Conclusion: it’s very loud, like the previous one. I strung it with D’Addario EJ83M strings, which they now call ‘Silverplated Wound’. They used to call them ‘Gypsy Jazz’, which was a dumb idea, implying that they were no good for anything else. They’re soft and warm toned, and excellent for any sort of musical style. But these are the heavier gauge, and I find them too stiff for my likes. I’ll probably go back to the same string in the lighter gauge: EJ83L, which I’ve been playing for years on most of my guitars.

I hope you enjoyed this repeat guitar build for the second time in a row. I thought it would be interesting to do it again, if only to compare with the first model “O” process. If anyone is inspired to try building a guitar then I will be very pleased. But remember that it’s probably a bit harder than it looks here.

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April 7, 2015 · 8:18 pm

Guitar #30/4

ribs and linings with glue – ready for the top

When last we blogged the guitar box was half assembled. I put the back plate on first this time, trying to save a little work by installing the linings at one go. It should have been fine but there was a hitch – the ribs weren’t quite as straight as they should have been, even though they were clamped in place in the mold. Sometimes you have to check things at least three times. This time I only checked twice. So the ribs are a little crooked. When this happens I resist the urge to smash the whole thing and start over. I figure that in time I’ll forget about the mistake and enjoy the guitar despite the imperfections. Then again there are always imperfections – they just vary in degree!

So I glued on the top, and then trimmed the overhangs top and back.

top plate with rubber band clamp

trimming the overhang with the router

Next step is to put on the bindings. I taped four pieces together and bent them all at once on the bending iron. Then I clamped them into one side of the mold to dry. I cut the channels in the meantime. The jig was already set for these bindings but after cutting the channels weren’t quite deep enough, and the bindings would have been standing much too proud of the edges, so I adjusted the depth and cut again. Then I began fitting bindings into the channels. Even though the bindings were all shaped to the mold they still required minor adjustments on the bending iron – numerous minor adjustments. So I did these one at a time, gluing on each one and taping it into place before the next one was begun.

bindings after drying in mold

guitar with bindings glued on and taped tightly

After the bindings were dry I removed the tape and began rough sanding the body. Because I’ve had some real problems doing this with power tools I elected to do it this time by hand. That way there’s very little possibility of gouging or finding that you’ve suddenly removed a lot more wood than you should have. I clamped the body using a foam camping mat in the workmate, and spent an hour or two sanding away with 100 grit and various sanding blocks. One very useful tool for this is a 2×4 about a foot long with a piece of heavy sandpaper on one side and a big handle on the back, like a large trowel. I also use some dowels to get into the waist area. I sanded the back too, and the top lightly. It’s surprising how smooth you can get hardwood using only 100 grit sandpaper.

After that I turned back my attention to the neck blank. It’s made up of 3 – 19mm wide pieces, and finished at about 57 mm wide. The headstock has to be wider than that, so I had to add two “ears” to it. Then later I cut it to shape, using a template I made long ago. I’m using the Selmer shape, and the headstock will have slots. I like the look of this, and I prefer the orientation of the tuners this way. They are a lot easier to manipulate on a slotted headstock than on a flat one, because all the shafts and buttons are horizontal. Very ergonomic.

gluing ears on the headstock

drilling tuner holes in headstock

As I mentioned above, I glued the ears to the headstock, then sanded it to thickness and cut out the shape. Next came drilling the various holes and slots. First I drilled holes for the tuners. The best and most reliable method I’ve found is to tack a steel plate from an old 3 on a plate tuner assembly to the side of the head. Then I clamp the headstock and neck to a vertical piece of plywood that is attached to another plywood piece that can be moved around on the drill press table. After drilling the tuner holes I then bored out four 1/2″ holes on the face, and cut out the slots roughly with a power jig saw. Lots of filing and sanding later the headstock is done.

headstock with tuner holes and slots – cut and sanded

Next up – the neck angle. Once the body has been all made and sanded the neck angle can be determined. Where the fingerboard sits on the top the surface is usually humped. So it has to be sanded flat. Then the angle is taken with an adjustable square. At this point it doesn’t matter what that angle is, because it’s too late to change it. With luck it should work and allow the correct projection for a bridge height around 15mm. A bit higher or lower is not a serious problem. So I take the angle and then transfer the complementary angle to the neck. If the body angle is 92 degrees, then the neck angle is 88, or 180 minus 92. The adjustable square does the thinking however, no need to do any calculating here. The angle is drawn on the side of the neck at the heel, at the 14th fret – where the neck meets the body, and 15mm beyond – the depth of the dovetail that will be cut.

taking the neck angle off the body

complementary neck angle transferred to the neck

The above photo shows the neck with the pencil lines, after I have cut and sanded the end face. Now it’s ready for the dovetail joint to be cut.

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March 31, 2015 · 9:48 pm

Guitar #30/3

Assembling the box

After days spent reorganizing the shop, which had become next to impossible to move in, I am back at it. Yesterday I bent the sides ( also called ribs) and assembled them to the end blocks. The end blocks had been made some time ago. These determine the rib depths and the correct angles at the four intersections where the ribs join the top and back (neck and tail). The first step was to trim the blanks to just a bit wider than the maximum finished width (depth of the body). I trimmed these to 104mm – the maximum depth being 100mm. That left me room to trim after assembling the ribs and blocks before attaching the plates. The next step was to mark each rib with yellow pencil at 25mm intervals. This is a great aid in checking progress against the pattern, which is also marked at 25mm along the outline. While I did this I had the bending iron heating up.

one rib trimmed and marked, and soaked down for bending

body half pattern with 25mm markings

bending iron hot and ready to go

Bending walnut is not very difficult. You keep it wet and hold in one place for a few seconds, pressing gently, then move a centimeter and press some more. The hot metal pipe dries the wood in seconds and it sizzles when it contacts wet wood. No sizzle means the wood is dry and has to be wet again. I start at the waist, then do the upper bout, then the lower. It takes constant small adjustments but with patience it can be made to follow the pattern shape quite closely. Once it is close enough it gets clamped into the mold, where it then dries and takes the shape in which it is clamped.

rib clamped to mold

Once both ribs were bent and dried in their final shape I trimmed the ends and assembled the pair of ribs into the mold, checking that the joints met tightly and along the centre line of the guitar. Then I glued in the end blocks. The easiest way to do this is without the mold, just one end at a time, clamping the ribs onto the block. Once both blocks are done then the assembly goes back into the mold and is clamped with spreaders.

ribs in mold with spreaders

The spreaders ensure that the ribs are in the right position for attaching the plates. Just a bit of pressure is enough to keep the ribs pressed to the sides and ends. I assembled the back plate first this time. I wanted to try a different method of gluing in the linings. First I glued the back to the blocks, neck and tail. Then I put the whole thing on its back and clamped the back plate here and there to the ribs, so it was tight. I then glued in the kerfed lining strips, rubbing them to increase the initial tack, and holding them pressed into place for a short time. In a few places I resorted to putting pressure with a re-purposed chopstick and a clamp. This saved me doing two steps, where the linings are first glued to the rib, after which the plate is then glued down onto the linings. This way I was also able to avoid having to cut pockets in the linings for the ends of the braces. Instead I simply glued several teeth from the kerfed strip at each brace. This will be sufficient to hold the brace end tight. Note here that I first trimmed and fitted the back plate to the ribs before this procedure.

gluing the linings to attach the back plate

After the back plate was done and the glue set, I then fit the top plate to the ribs. Then I glued the linings for the top in place. Since my main top x-braces are tapered to zero they require no pockets in the linings, except for two which hold the upper face brace. These will be cut before the top is glued on.

box ready for the top plate final fitting

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March 24, 2015 · 8:52 pm

Guitar #30/2

installing truss rod & carbon fiber rods

I decided to do some work on the neck blank today. The sun was shining into the carport this morning when I set up my workmate and clamped the neck blank in place. Fetching the router I found that it had the truss rod bit already in place and set to go. I attached the fence, made some adjustments to ensure I had the center lined up, and then routed the slot in a jiffy. I went to put the truss rod into the slot next. It didn’t fit! I looked a little closer and discovered that my supplier had changed their truss rod in a very small way, but now it was wider by about one millimeter. Problem: no 12mm router bit. I looked through my bits and found one that was 1/2″. Close enough, so I swapped it into the machine and set the depth, then ran it down the groove, shaving off the millimeter required. Only now the rod was a bit loose. No major deal here, I put electrical tape on the rod, which made it snug in the groove. But if they keep sending me 12mm wide truss rods I guess I’ll have to buy a 12mm bit. I have learned that it is sufficient for a truss rod to be installed without glue, and in fact I think it’s better. That way if it ever breaks it can be withdrawn and replaced. If it were glued, forget it – make a new neck.

neck with truss rod and carbon fiber rods glued in

After the truss rod groove I switched to a new 1/8″ bit and routed slots for twin carbon fiber rods I recently bought. I cut one long piece in two, sufficient to do both sides of the neck. These were glued in place with epoxy. The slots had to be widened for these just a bit, which was done by adding tape to the sides of the neck blank and to the router fence for a second pass at the slots. After that the carbon rods dropped right into place perfectly.

carbon fiber rods before gluing

the bit for the old truss rod

the new wider truss rod

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March 23, 2015 · 12:23 pm

Guitar# 30/1

Before I head off with this post about my next guitar, here are the real answers to the last blog.

1. Common Bulrush

2. Western Painted Turtle – Vancouver Island’s last remaining native turtle species, and unfortunately, already endangered.

3. Double-crested cormorant

4. Ring necked duck

5. Northern Flicker

Now for something completely guitar:

Here is the top of #30, ready for assembly. It’s the same as #29, that is an x-braced domed soundboard. This one is Sitka Spruce.

Guitar#30 top – bracing

Here is the back plate. Unlike #29 I just went with regular ladder braces. Less work. Spacing was done by eye, more or less, but I placed the braces on more or less even centimeter marks, as can be seen if you zoom in on the tape. The arching was done with a template I had, giving a set rise over a given length. In this case 5mm in 400mm. I drafted the “fair” curve with a bent rod and pins.

back plate, braced

back arch template

The interior body blocks are a little different this time around. The tail is still 100mm deep inside, but the neck is deeper – 90mm. The Martin I used to get the sizes of an “O” guitar had a shorter neck block, (81) which I decided was too short. About 10mm difference is more to my liking, and that also makes for a slightly greater interior volume. It also aids in the fitting of the back to the ribs, as you will see from the next photo.

mock up of plates with blocks

Here I have clamped the plates to the blocks so I can see how the angles on the blocks work out.

neck block with dimensions and angles in pencil

tail block as per neck block

The angles are often best guesses as after assembly they seem to change mysteriously. The key angle is the one that sets the neck. For that I am using 1 1/2 degrees. The upper face brace arch dictates this, more or less. I’m aiming for a bridge height of 15mm, which this should give me.

dry run assembly with popsicle sticks showing the body depths

The body depth is 100mm from the tail to around the waist. Then it tapers at the back side down to 90 at the neck block. The first 5mm of taper occurs between the waist and the upper bout at its widest. The plates are shown here in their natural curved state, clamped to the blocks. The soundboard face of the ribs will be flat, and the back face will be flat until the waist, then tapered.

fingerboard already fretted, ready for assembly to neck

This is a Bubinga fingerboard. It’s hard and tough, and a lovely pinkish colour. Also cheaper than Rosewood or Ebony. I did this all at once, starting with cutting the fret slots, putting in dots, tapering the sides, sanding to 16″ radius, then fretting. I double stick taped the wood to a bench to do the radius sanding and then put the frets in right there. After I nipped off the ends I pried it up and sanded the edges straight on the bench belt sander. There’s still an extra millimeter on each side. I always leave room for insurance.

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March 22, 2015 · 12:03 pm

The Junior Naturalist

No. 1

We live beside a small pond called Swan Lake. We never see swans here, however. It’s a bird sanctuary, in a park that by some miracle was never destroyed by development. Thank you for that, whoever you were that was responsible. Daily, we walk around the lake, a distance of about a mile, which takes 45 minutes almost invariably. Sometimes I carry a camera, but we have a joke that whenever I do so, we see no wildlife worthy of a photo. Of course when I leave the camera home we run into owls and hawks face to face! But I still like to lug the camera sometimes. Yesterday I put on my 500mm mirror lens. It’s a Tamron, and in its day was very expensive. I got it at a thrift shop for $65, which is not much. I regularly see photographers on out walks, carrying gigantic telephoto lenses mounted on tripods worth more than my camera. All for taking pictures of ducks? I don’t know what they do in truth, but as amazing as those lenses must be, I will probably never buy one. I’m more of an opportunist – I hope for good shots to present themselves randomly. As long as I have the camera at hand, turned on, and set to the right settings of course, then sometimes I get a lucky shot. This long lens is hard to hold steady, however – it probably requires a tripod but I’m too lazy to bother. My Pentax K50 has built in shake reduction, and with my shutter set to 1/1000 I shoot and hope for the best. Of course I also have to focus manually, which is the trickiest part. But here are a few shots. I have numbered them. It’s a quiz! Guess what they are. My answers are below.