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

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 4

body and neckNow it’s time for finish and assembly.

The first thing is to fit the neck to the body in this case with bolts (I’ve mentioned this method in several different posts).  When I’m satisfied, I make sure all of the pin holes and gaps are filled so I don’t have any sinking finish and seal and fill the grain with marine epoxy.

I’ve described the finish process before so I won’t go into much more detail than to say I spray about 6 coats on the top and about 8 or 9 on the back and sides.  I wet or dry sand every 2 coats and try to get the entire job done in 2 days.

I let the whole thing dry for about 2 weeks and do the final compounding.  I finish the neck and body separately to make the job easier.

When I’m satisfied with the gloss, I put the neck on for the last time, gluing the fret board end to the body.

Next, I locate the bridge and carefully glue that to the body.  I then drill the bridge pin holes, taper them for bridge pins and relieve the hole with a slot for the strings.  I make a saddle and nut out of bone and fit those to the bridge and neck.

I then fret the instrument using compression fretting.564After this the frets are dressed, the tuning machines installed and the guitar is strung up for the first time.

I have to say I still get a big kick out of hearing the guitar’s voice for the first time.  Of course all the bugs need to be worked out and the guitar set up.

And finally… the new owner plays it for the first time.  IMG_7747Cheers, and thanks to Tim Pacheco!

Mark

Color Match Finish Coats

Now that we’ve got the color match we can complete the finish.

I then spray the top coats.  I start by lightly spraying in alternate patterns.  Horizontal then vertical, and then switching to diagonals to get the most even coverage.  I shoot 2 to 3 coats a day then sand with 320 grit wet or dry, being careful not to sand through the color coat.

Lacquer and other top coats follow, they don’t fill.  That means that the lacquer will flow into the depression not fill it up.  By sanding in between coats you are taking off lacquer on the surface while not touching the depression.  The next time you spray, the depression will be that much smaller.

I usually spray between 6 and 9 coats to get the desired result.  Prep work is critical because the less depressions and holes you have the less you have to finish.

When I’m satisfied with the raw finish I let it dry for a minimum of 2 weeks to allow the finish to cure and shrink.

When the finish is dry, it’s not a simple mater of putting the guitar together. The finish has to be compounded to smooth out the ripples.  Compounding is going through a series of abrasives until the surface is smooth and mirror like.

I start with no lower grit than 600 wet or dry and usually 800 grit.  I use the best quality paper. 3M Imperial wet or dry seems to work well.  The cheaper papers have larger stray grit in them and can cause scratches that are almost impossible to remove.  This is also the case if you start with anything coarser than 600 grit.

The first sanding is the most important. I lubricate with water to float the particles off and for less loading of the paper. It’s very important that you use a hard rubber, cork or felt pad to be sure of a flat surface.  Never sand with you fingers.   I make sure all the gloss is taken off so that the surface is dull but smooth and uniform.  Now I switch to Micro Mesh.  This is an abrasive in cushioned latex that doesn’t build up as easily and is very high quality.  The 1500 grit is equal to 600 grit sandpaper so I start with the next one up, 1800.  I continue with this to 4000 grit also using water as a lubricant.  Then I switch to another abrasive, Abralon.  This is a 6″ pad I use with a 5″ random orbital sander.  Using 2000 and proceeding to 4000, I use these pads dry.  I leave the 6″ pad full size to protect the guitar from the rubber pad on the sander.  In tight corners, I use the pad by hand. One thing to remember is to clean off all the previous slush so that the next grit starts fresh.

Now the fun part, using a buffer to bring the gloss up!  In reality all you are doing in each step is to make the scratches finer and finer until they appear to go away.  I use a Shop Fox buffer and 12″ domet wheels.  I make sure not to contaminate the compounds with the wrong wheel.  While they make several grades, I stick with the fine and extra fine.

Buffing wheels can be very dangerous if you’re not careful with the way they are used.  Remember when you’re buffing to only buff the bottom half of your piece.  Right

Wrong.

If you use the buffer like this you will run the risk of catching the upper surface and having your piece thrown to the ground.  I believe you will not like the result much so be aware of your orientation.

I do the same thing with buffing that I do with sanding, changing direction of the piece’s orientation with the wheel: horizontally, vertically, and diagonally. When finished with the fine wheel, clean the surface of the piece to clean the previous compound then proceed to the extra fine.  Wax is not recommended and will in fact make the piece duller.

When you’re done you should have a mirror finish to be proud of.

Color Matching an Existing Finish

Sometimes you encounter situations that require you to color match a finish.  In this case it is with a bass guitar that had its peg head shape altered and the client wanted me to match the finish as close as possible to the rest of the neck.As you can see, the fret board (as is the rest of the neck) is a dark amber color, much darker than the rock maple.

First, I sand to 220 grit to get rid of any scratches and prep the surface.  In fact I do this even if there aren’t any scratches to make sure there is nothing contaminating the wood.  Then I apply my sealer, in this case shellac.  You can also use vinyl sealer, epoxy and sanding sealer but in this case it was handy.  When it comes to shellac I try to always use flakes dissolved in alcohol with a date on it to make sure it’s fresh.  I usually use a 3 lb cut as a sealer.  This refers to 3 lbs of shellac dissolved in 1 gallon of alcohol.  It lasts for about 6 months so I don’t mix more than I can use in that time period.  It should be dry to the touch in minutes, and if it doesn’t it’s old and should be thrown out. The pre-made shellac in hardware stores contain too many additives such as plasticizers to maintain shelf life.  An interesting thing about shellac is that it’s considered a food product by the FDA and it’s what coats M&M’s.

I don’t like to stain bare wood for two reasons:  One it looks blotchy.  The soft parts of the maple will take more stain than the hard parts.  Two, if I screw up the color, I can take it off easier.  Here’s what it looks like with the shellac applied.

I mask off what I don’t want finished and mix my color.  I don’t normally shoot lacquer but in very small amounts I can get away with it (I’m allergic to the stuff).  In this case I’ll be using TransTint dyes sold by Stew-Mac, amber, red mahogany and medium brown.

Most of the color matching comes from practice.  I’ve done a lot of these so I use my experience to make a guess as to the colors and ratios.  In about 4 oz of lacquer I put 6 drops of amber, 1 drop of red mahogany and 1 drop of medium brown.  It’s very important to make a record of this and keep it in a journal.  This way you will be able to correct the formula if it isn’t right and repeat it if it is.  I test the color on a piece of paper and in this case it was pretty close so I went ahead and shot the peg head.  I do very light layers until I get the desired shade.
As you can see, it’s a pretty close match.

Next week, the finish coats.