Monthly Archives: August 2011

Finishing

Well this is almost it. I actually started to do the setup the other day. I got a preliminary setup complete and even stringed it up (couldn’t wait) and played a couple of songs. But I am reeling in sweat just sitting down and it was getting on the bare wood so I decided to put that idea away, get the finish on it and then come back to setup later.

Sorry I forgot to post abut making the saddle so I will also come back to that one later.

For the finish I will go with my standard BLO/Tung/Varnish mix on the entirety and then do a nitrocellulose spray on the body. I like the feel of natural wood on a neck so the neck will be only BLO/Tung/Varnish. I will also use some pumis stone powder during the BLO/Tung/Varnish stage.

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Here is the guitar – bare bottom and strung up.

All taped up and ready to go. I already have a coat on the back, sides, and neck.

Various angles of the guitar with three coats of BLO/Tung/Varnish and rubbed in pumis stone powder. (I didn’t do a pumis stone rub on the spruce top. Only on the hardwood.)

For the nitrocellulose spray I will have to wait a bit. It will likely get done this month or early next. No hurry and I will be doing some practice spraying.

Since doing the above guitar I have come to learn about a more traditional method of finishing – French polish with natural shellac. It is truly a beautiful finish that has a high sheen, is quite durable and easily repaired in the event it needs to be done. I recommend this method over the above as it does not require expensive spray equipment, can be done on your bench-top, and the curing time is so much quicker than oil based finishes. The only caveat is it takes a little practice.

For your material setup you will need the following:
De-waxed, blonde shellac
Ethyl alcohol (99.5 percent pure)
Mineral oil
Pumus stone powder
A wad of cotton or wool wrapped in a square of cotton
A plastic squirt bottle

1. For a sealing coat dissolve 56 grams of shellac into 100ml of ethyl alcohol. This is called a 2lb cut.
2. Using your squirt bottle and pad applicator soak the pad just enough to be full but not dripping.
3. Begin to apply in circular motion over the surface you want to finish. Move around quickly but not furiously.
4. Put a dab of mineral oil on your pad every time you fill the pad with shellac. This keeps the motion smooth.
5. Let that dry for an hour or two and then sand smooth with 600 grit wet or dry paper. Use a little water if you like.
6. Next dissolve 56 grams into 200ml of ethyl alcohol. This is a 1lb cut.
7. Following the same procedure soak your pad, dab some oil and apply in circular motion.
8. With a 1lb cut you will be able to apply many coats (up to 12 or 15) in one sitting. Do the same the next day.
9. Finally do a rub out with the pumis stone powder and mineral oil.
10. Put some oil on a separate pad and some pumis stone powder and start to rub it into your cured shellac in circular motion
11. Buff it off with a clean cotton rag.

 

Posted in Finishing, French Polishing | 1 Comment

Saddle Slot and Bridge Height Adjustment

Back to the bridge where most of the action has been playing out this week.

In the post before the last two I attached the bridge. after completing that task I needed cut a saddle slot and then to put a 16″ radius on the bridge to match the fret board.

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This is a piece of bone I fashioned into a saddle. I will use it to help me find the compensation I need for correct tone on the strings. That is to say when the string is tuned to pitch and you put your finger on the twelfth fret the note should be exactly one octave higher, not sharp or flat. Different string gauges reach their pitch at different string lengths. this is where the compensation comes in.

With the makeshift saddle in place I tune the string and find the spot where the twelfth is one octave higher. Then I mark the spot where the saddle sits.

Once I have done the high and low string I draw a line connecting the two points.

This is my two-bit jig that does the job right with a tester in place.

The cut was too wide so I dialed it in with a spacer and my drum sander; taking a little off the spacer then doing another test cut, etc. When I got it dialed in I was ready to do the cut on the real thing.

My jig in place with my Dremel tool fixed with a 1/16″ bit. When the jig was in place there was no play whatsoever and the Dremel tool is so lightweight I didn’t even have to clamp it.

The slot cut 6mm deep. A little difficult to see but there is a pencil mark to the height of the frets with a 16″ radius.

With the slot cut I was ready to take the bridge down to the pencil mark. I use a piece of a broken flat bastard (that I broke intentionally for stuff like this).

now that the bridge is down to the correct height and radius I can ream the holes to fit the pegs. Go slow and check often those reamers cut fast.

All the peg holes reamed to the correct diameter.

With the un-shaped saddle in place.

As a side not to any of you folks interested in doing break down furniture. The reamers I used do a wonderful for that. I used a small diameter reamer but Stu Mac sells a larger one also that I think would be quite appropriate for break down furniture.

Posted in Martin Style Pyramid Bridge, Saddle Slot | Leave a comment

Side Position Dots

After doing the frets I realized I did them in haste as I forgot to do some intended inlay on the fret board. So I had to decide to pull the frets and start over or go with no dots on the fret board. In the end I decided against pulling the frets as I would risk messing up a clean job. As well I justified this decision by telling myself the uninterrupted grain running from the head stock to the end of the neck was beauty enough for me. Am I a woodaholic or what?

So I did put some dots on the side of the neck. These dots are 3mm Mexican mother of pearl. I used a 3mm brad point bit to drill the holes.

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3mm finger placement dots at the 3rd, 5th, 7th, 9th, and 12th fret.

A close up. They are sized a perfect 3mm.

On one of the holes I drilled a little too deep. The fix however was easy: Fill the hole with ebony sanding dust, tamp down to desired depth and put in a drop of CA.

Posted in Fretting, Neck | 1 Comment

Fretting

This job was actually done a while back – before I did the bridge. But It was incomplete so I didn’t post it. Now that I am coming back to it I see my pictures are not compete. So bear with me on this.

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Here I have pictured a fret bending jig. It was pretty simple to make. The hardware comprises of three 8mm nuts, bolts and washers, and four bearings attached to a piece of plywood on a 16″ radius with the two outer bearings equidistant from the center.

A close up of the jig. The tange of the wire rides in between two bearings in the center.

With the fret wire bent to the desired radius I cut it to length and hammer it into the cut slot.

Make sure your slots are deep enough. Sometimes the slot has to be cut a little deeper.

There were a couple where the ends of the fret wire didn’t hold down on the ends. The fix is some CA glue in the trouble area.

After the frets are in you have to file the ends at a 45 degree angle because they are sharp.

Then you have to level the frets (not pictured), and then crown them with a crowning file. You can see in the picture I have a fret rocker, which checks for high frets using three points when laid on the frets. Also not pictured is the polishing you have to do after the frets have been crowned. For that I used my Dremel tool with a polishing stone.

I found fretting the fretboard to be a little more difficult than anticipated. Not that it is a hard task but you have to develop a feel for it and that is something that comes after practice.

Posted in Fretting, The Fretboard | Leave a comment