Building a Harp Guitar Part IV

Now we come to the point where it is looking like an instrument!

IMG-20130108-00229The top and back have been trimmed and the binding channels have been cut.  This is pretty much the same as on any guitar… just more of it!  Any of the systems by Stew-Mac, LMI, Luthier Tool and custom setups etc. will work.  For this set up Scott used the Luthier Tool binding cutter with a bearing bit setup from LMI.  Most of these cutter jigs use some sort of trim router and this is no exception.  luthier tool binding cutterThis picture is from their website http://luthiertool.com/binding%20cutter.html

As with any system, it takes some practice to become proficient.  The jig has two bearings one on the top and the other on the bottom of the leg.  These have to be in contact with the sides in order to maintain proper depth and width.

The neck on this guitar is a conventional bolt on slot head so I won’t go into much detail on that as I’ve covered this on other posts.

IMG-20130115-00234The finish, while pretty straight forward is complicated by the size of the instrument.  Some creative ways of positioning it for spraying are necessary.

I use a length of 3/4″ pipe and attach it to a saw horse and to the body where the neck attaches.

The other issue is supporting the body for fretting when the finish is done and the neck attached.  A Taylor fret buck is worthless because the harp arm won’t support the edge of the buck so it will give too much when it’s in use.  I use an arbor press when fretting and in this case the body has to be supported when fretting over it.  To solve this, I made a jack to support the top.  I used two pieces of wood about 1/4″ thick, one for the top and one for the back to distribute the pressure and put a small scissor jack http://www.stewmac.com/shop/Tools/Special_tools_for_Brace_repair/Scissor_Jack.html
to support the pressure.

In the future, I would probable use a neck joint that would allow fretting before the installation of the neck to the body.

Other than the things mentioned, building a harp guitar in theory is not much different than a standard 6 string.  In practice the larger scale and added strings do add to the complexity above and beyond a 6 or 12 string.  IMG-20130124-01093Photo of Don Alder by Scott Burwell Holloway.

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Building a Harp Guitar Part III

There are several ways to make rosette channels from a simple hand held trammel and chisel to a purpose built cutter.  I do several a year, both for my own instruments and the classes I teach, so I use the latter from LMI. There are others available such as one from Luthier Tool. The LMI setup is kind of a pain to set up initially but once set up works very well. I’ve used several products from Luthier Tool and while expensive, they are beautifully made and easier to initially set up.

The problem is the small rosette and sound hole for the harp.  It’s two inches plus and will not work with the conventional cutters.  For this one I took a simple General circle cutter, re-ground the cutter to my rosette dimensions and replaced the center drill with 1/4″ drill stock with a bearing fixed to the top.  When the depth of the cutter is fixed the bearing stops it at the proper depth, much the same as the commercial cutter.

circle cutter

Now the back and top have to be fitted.  I use binding that is a full 1/4″ so that I can cut out the sides and let the main braces of both the top and back run through.  I feel this makes it easier to keep everything aligned.  271Of course, if you are doing a style of guitar without the binding like a Dyer Style 4 you have to inset the braces to the sides because there is no binding.

I always put the back on first so that I can facilitate clean up of any glue left in the joint between the back and the sides.  I use a slow set Titebond and spool clamps to joint the surfaces.  To quote Wyatt Earp “Take your time… in a hurry.”

Before I glue the top to the sides, I make sure the sides have not deformed.  If they have I sand them again to the proper radius.  I then repeat the inletting for the top braces to the sides and glue the top on.

Next time:  Binding and finishing.

Building a Harp Guitar Part II

Now that we’ve got a bit of history, let’s move on to the actual build.

Even though it looks radically different from a conventional steel string flat top it wouldn’t be foreign to a builder of the latter.  It has an X brace and size that closely resembles a Martin 000. The difference lies in the extra X morticed into the lower half of the bass side to reinforce the top for the 6 harp strings. The bridge plate is also larger to accommodate the extras strings as well.

This is not to say that it is an easy build.  The hollow arm is essentially a hybrid of neck and body, having a head stock and a sound hole.               SH top

The back is pretty similar to a normal steel string as well.IMG-20121220-00204

The head block for the harp head is also a complicated affair that requires some well thought out jigs to reproduce with consistency.

SH harp head

Everything in the build is bigger, including the forms for the body mold.IMG-20121220-00203

A radius form is used for the bracing and grinding the sides to the correct curve.   Instead of a 2 ft. round form a 4 ft. is needed.IMG-20121220-00206All this can add greatly to the expense of gearing up.  I have to say I get a kick out of people asking why hand built guitars cost so much!

The sides are bent using heating blankets (bigger as well) on specially made molds to accommodate the multiple bends.

Next week, sound hole quirks and getting the back and top on.

Building a Harp Guitar

I’m back after a three month absence.  Whether that’s good or bad is up to you.  style8

I’ve been helping Scott Burwell Holloway get his harp guitar company going and this is an example of a Style 8 Dyer Symphony that we completed in January for the NAMM show in Anaheim.

First a little background on the instrument.   The first “modern” harp guitar was invented by Friedrich Schenck in Vienna in 1839.  It was a “hollow arm” harp integral with the guitar body.  Schenck was a student of Johann Stauffer, who also taught C.F. Martin.

The turn of the 20th century saw a resurgence of harp guitars in the US. Orville Gibson made four models and although they sold for from $194.03 for the style-R to $354.60 for a U-1, 400 were sold.

Most people consider Chris Knutsen to be the originator of the American harp guitar.  Although it’s similar to the Schenck in that it had an hollow arm it was more integrated into the body.

This brings us to the Dyer Brothers, who contracted Knutsen in 1899 to build harp guitars for them.  By 1906 the Dyers had switched from Knutsen to the Larson Brothers in Chicago (possibly because Knutsen kept changing his instruments).  The Larson’s made very high quality instruments (Prairie State, and Euphonon are two brands) and improved on the Knutsen design giving us the most famous harp guitars made.

When I say we made a Dyer #8, it really is a modern Dyer as Scott owns the Dyer name and has committed himself to building faithful copies of their designs as well as what he thinks the Dyers might have done had they taken the harp guitar into the 21st century.

Scott is a wealth of information on all things harp guitar and has many historic examples of Knutsen’s and Dyer’s in his collection.  He is also a phenomenal concert level player, having studied under the late Michael Hedges and Will Ackerman, founder of Windham Hill Records.  As far as I know this is the first time in recent history someone has considered a factory instrument as all the moderns ones are from hand builders.

Next week the beginning of the build.

Bespoke Guitar Part Three

Now that we’ve got the body done, it’s on to the neck.

I start with pattern grade quarter sawn genuine mahogany.  This is a very stable and relatively lightweight wood that has been used successfully in both instruments and furniture. The first thing I do is to square it off with a plane, then cut the truss rod channel and the two channels for the graphite reinforcement.  Once this is done I cut the profile for the neck and glue on the peghead overlay, in this case, book matched camatillo.  My client wanted a slotted peghead so I used a jig I made to cut the appropriate slots.  After the truss rod and the graphite bars are installed the head stock is inlayed with my logo and the fingerboard prepped. In this case the fretboard is bound in rosewood to match the binding on the body.

Now I glue the fingerboard on, being careful to keep it aligned with the neck.  After it’s dry I start to profile the neck.  As I have mentioned before, I find this easier to do by hand as I can finish the job in about the same time it would take me to set up a CNC.

The final post will be finishing and putting the whole thing together.

Re-fretting a Bozo

While I’ve done a post on re-fretting a guitar I thought it would be interesting to see some of the tools I use.  A small three corner file to bevel the edge of the fret slot so that the frets go in easier and when they have to be pulled less chipping.This is the tool I made for putting the 30 degree bevel on the fret edges.  It uses a mill smooth file with a high density, low friction plastic base.Flush ground end nippers for cutting frets close to the board.This tool cuts the tang off the fret ends to go over the binding.This is a small needle file with the edges ground and polished so I can remove the sharp edges from the fret end.This contraption I call Frankenfretter.  It’s a sliding base I bolt to the drill press to support the guitar while I compression fret it.  Notice the Taylor fret buck, a massive support for the guitar body while I fret.And finally, the finished job.