Archive for May, 2009

Sometimes building a Guitar seems to me to be a series of leapfrogging from one “Disaster” to another. Notwithstanding that I try to build by my Motto ”Measure Twice cut Once”,which really means “THINK ,THINK, THINK”, there are the occasional MISTAKES that you have no control over and will happen in any event. Just such a tale I will recount, because the consequences could so nearly have resulted in my whole shop burning down, with hugh property losses, if not loss of Life. In other words  —- this could have been the BIG one. The tale goes like this:

Burnt Templet in Bender

I had just ordered and with much excitement, received my first and very own,  side bending machine from LMI. It was a Fox Machine, with all the “bells and Whistles”. I dutifully unpacked the box ,took it out (they come pre-assembled) and made the minor adjustments to the machine ready for bending. It was a 220v unit, as Australia has that power supply value at the Mains. With any bending machine that is currently on the market you have to build your own templets for each Guitar that you wish to bend sides for.

Burnt Mahogany sides

I was making an OM, in Honduras Mahogany, with an Adirondack top. One thing I have learnt the hard way, is to read the instructions — so I did —and I followed them to the letter. Unbeknown to me and to LMI, the Electronics in the main  unit was supplied without a thermostat , designed to control the heat generated by the unit and transfered to the Timber being bent. I can tell you, from bitter experience, that the heating blankets, supplied with these Units,  heat up to about 450 Deg. and very quickly. The unit is also supplied with a DVD, —- which I watched — so,   HOW  COULD I GO WRONG?

I spritzed the sides,wrapped them in silver foil and after pre heating the stainless steel bending strips, slipped the wood between the strips ,turned the appropriate dials to 15 minutes and sat down to wait for my sided to bend (there was a little bit of winding and pulling) but essentially all I had to do (SO THE INSTRUCTIONS SAID) was sit back and WAIT.

Well I didn’t have to wait very long. 

After about 5 min I noticed the first whiff of smoke, by 8 min thing were cooking very nicely, thank you,and I didn’t get to 15 min. At about 12 min mark the automatic fire alarms were wailing, I could not see from one side of the shop to the other because  the smoke was so thick and the OM Templet in the Bender had caught on fire and flames were beginning to envelop the machine. In other words we had a full blow emergency on our hands.

I reacted by cutting the power to the machine,throwing a fire blanket over the whole unit (which put out the fire) and with the use of fire Gloves was able to salvage the Bender but not the Heating blanket,OM Templet or the Mahogany sides.

The blanket and Templet were destroyed and the sides were literally burnt to a crisp, in fact they were burn into little Black chips. As with all my experiences as a Luthier I recorded all of this, Digitally, I know not why,but I did.

I have to say that LMI were superb (but that won’t come as any surprise) they leapt to my aid, replaced everything that was damaged and threw a few practice sides into the deal. ( an Indian Rosewood set was so good I made a Guitar out of them).

It transpires that the Manufacturer does not supply a thermostat with a 220v machine (work that one out) and forgot to tell LMI. I was the first bunny to purchase a 220v machine from LMI, so they were not aware of the problem. They are now. 

So how do I bend?  —— VERY CAREFULLY.

In fact I bend in the machine by ear and feel, I apply power, I turn the unit off,then on again ,I listen, I spritz the metal bending strips, I wind, listen again,apply heat etc., I am sure that you get the Idea.  BUT IT WORKS AND IT WORKS VERY WELL FOR ME.    

Have a look at theses Pictures, they will make your hair curl.

Of late I have been using a Vacuum Cabinet to Glue joints, fretboards, braces and various other joins where the Cabinet is the appropriate medium to use.

I learnt dramatically what can happen if the piece that is being joined is not braced properly.

Snapped neck in Vacuum Cabinet

in the Pictures associated with this post  you can see what happened to a neck and an inappropriately supported jig, if proper care is not taken to brace the neck and it’s jig. The forces at work in the Vacuum Cabinet snapped this neck like a twig.

Once the neck had been shaped to my satisfaction the fret board was slotted to a 25.4 scale and preparations were made to fit the head plate fretboard to the neck.

Slotted Fretboard and Plate placed on the neck prior to "The Set"

I must comment at this stage, that one of the most critical procedures, in whole process of making a guitar, is the setting of the neck. If the right angle and  neck alignment are not achieved, then in my view, there is no point in proceeding. If the box is good, but in setting the neck you have shaved off too much wood around the Tenon joint, I would through the neck away and start again. I have to admit that I have “botched” a neck set so badly that I had no alternative than to start all over again. I mucked around for nearly two days trying to fit the neck and in the end, the neck looked as though it was about to join at the thirteenth fret rather than the fourteenth, however I learnt a very good lesson, “Measure Twice Cut Once”.

I frankly think that I have bitten off more than I can chew,so to speak.

This job should have been done much sooner, however with my other commitments and the workload that i have set my self by having four(4) Special Projects on the go has meant that I have been a little tardy  with some of my Project work. I will have to see that this does not happen again.

Joined back

I joined the back with bold zipper Marquetry strip, not the usual strip that I join my backs with, but I thought that this particular style of timber (Lacewood), lent itself to this type of  strip because of the Timbers  very busy natural pattern, I would be interested to hear your views ,as this timber is not used very often in  Acoustic guitars and I think it’s a great shame, as I am sure that you will all agree, it is beautifully patterned timber.

I have not concentrated, in the past, in building Classical Guitars, however in looking through my wood supply the other day, I came across a particularly beautiful Ziricote Set, that I immediately thought would lend itself to a Classical Guitar, particularly when matched with a Master Grade German Spruce top and Honduras Mahogany Neck.

Ziricote back with bent sides

I got to work and bent the sids and joined the back with a Madagascan Rosewood and Basswood strip. I was extremely  pleased  with the results,so far.

I have put all the pictures that I took during this exercise into the Carousel with this post,click on any picture and it will pop out of the Carousel and enlarge itself. I hope you agree, that so far this is looking good.

Once the sides have been bent and placed into the mould, the tail and heal blocks are stuck in place and then they ( the sides) must be cut down to the desired hight. That hight is determined by your plan. I stress your plan, as it is at this stage of construction that you may want to make changes to the depth of your box, as I have done with the instrument in”PS3″, as I have made the box a little deeper, than found in the more traditional OM.

I mark the desired hight on the sides with a white or yellow pencil and then connect the dots, which gives me a line to work to.  There are more efficient ways of doing this, such as marking the profile before bending the sided,I just seem to forget to do it, which frankly is annoying as It would make my job a lot quicker, particularly if I cut off the excess wood  after marking and before bending.

I then take my very favorite Block Plain and Plain the sided from the middle of the large bout down to the neck block. 

I found this timber (Malaysian Blackwood) very brittle and quite difficult to work and as you can see from the pictures, I had one break out that had to be repaired. I have to say, that I considered myself fortunate to only have one.

Break out on the left side about the middle to the large bout

Repairing splits ,cracks or breakouts is really ,”no big deal”, with the Luthiers Friend,  —super glue—, and a little care, a repair of the site can be effected, so as to be unnoticeable.

In the next post I will cut out and brace the back, I am building this Guitar to a 12/25 radius of the back and front, therefore the back braces will be radiused at 12′.

(CLICK ON THE PICTURES IN THE CAROSEL AND THEY WILL POP OUT AT YOU)

In building my necks I use the finest pattern grade,quarter sawn Honduran Mahogany neck blanks ensure that the blanks have consistent density and homogenous grain, for this means excellent stability and workability, furthermore Honduran Mahogany is the preferred wood for steel guitar necks.

The neck for this instrument was cut from a single blank although I prefer the scarf jointed neck,for reasons that I will explain later.

If you examine the Pictures with this post you will see the various staged that the neck progresses through before it is ready to accept the fretboard.

The fretboard that I chose for this neck is a Madagascan Ebony blank.

The fret slots are cut on a Jig, following plans that are supplied with the  LMI’s Power Slotting System (page 126 of the LMI catalogue). If you intend to make more than one Guitar, then this system is invaluable, you must however be prepared to purchase a dedicated bench saw that jig sits on permanently, in other words the saw and Jig are one permanent fixture in your shop, in my opinion if you do otherwise you run the very real risk of introducing slop and error into one of the most critical processors in the making of your Guitar. I have made a few modifications to the standard System, you will notice that I have added a couple of De-sta-co clamps to the fence, this helps greatly in holding the fretboard and templet in position when cutting the slots.

The Power Slotting Jig on the dedicated saw bench

Two kerf sizes are offered with the system, I chose  a .023″ blade ,as this matched the fret wire Tang that I prefer to use. A blade with a .025″ kerf is also available.