Class 2 (Thursday Night)

We had a lot of work to do on Thursday, especially since no class on Saturday for the upcoming Labor Day Weekend. The agenda was to attach the sides to the Heel and End Block, then radius the back of the guitar to a 30ft radius, the top to a 15 foot radius and attach the Kerfling used to support the back and front and create the insert for the end of the guitar. We had our heel blocks created and the sides bent from the last class, so our first task was to glue the blocks in place. We had to measure the sides and trim them to fit in the form and not overlap. We were able to do this quickly and set to glueing the blocks.



Cian had to use his "high-tech glue applicator" to apply the glue to the block. While glueing may in and of itself may seem simple enough, it is key to a great majority of the steps in building a guitar. Not enough and you risk jeopardizing the strength of the guitar, and too much you have a real clean-up issue on you hands.

We thought this was too much and ended up reducing the amount considerably, probably too much reduction because once glued there were areas that while I am sure they are secured, you could not see the glue on the edges. So as with everything in life it is a balance that is learned. Just not to be taken for granted.

Here is a photo where both the Heel (neck) and the End (bottom) of the guitar are in place and clamped for the glue to try.

Just a close up of the clamping process. Note that we have clamped it from the top and bottom and removed the sides from the form.

This picture just shows it from another angle.  Clamps on the bottom and top with cardboard protecting the wood of the sides.  You will notice that where the sides meet don't match up exactly.  While it is perfectly ok for them to match up precisely, it is not absolutely necessary as wood is removed to allow for the neck and end piece.  What was a little more critical would be that those sides are parallel and did not have an angle, since any angle at this point produces some 'twist' through the sides.  We had a little, but believe we can compensate with the planing of the guitar later in the process.  But a good lesson for future builds...

Now comes the arduos and "pucker producing" task of planing the guitar.  The two ends are not the same size so there is a general "sloping" that occurs from the end to the neck heel of the guitar.  Using a hand plane the sides width is reduced from around 110mm to around 100mm.  Together with the top and bottom attached the total width of the guitar should be about 105mm.  You need to be very careful that the plane does not grab the grain and create a crack in the sides.  We had two colleagues have this happen.  It can be fixed with application of super glue.

In this photo Cian is checking the radius using a radius dish with assistance from Jim.  These are dishes that have the appropriate radius to them.  You turn the guitar over, lay it in the dish and check for spaces.  The guitar should fit nice and flush and not allow any sunlight through.  This identifies high spots and where to plane.  We did run into an issue here where we had a high spot on one side but when we flipped it to plane that side gets reversed and we were re-planing the low spot instead of the high spot.  Another lesson learned, easy to get confused where your top and bottom, right and left are when you are flipping these around.  We believe it is a minor problem but will probably result in the neck area being slightly more shallow than the plans called for. 

You may notice that there is sand paper in the bowl.  You can take the guitar body and "twist" it in the bowl which will sand it.  We have learned that sanding is useful but only used when needed.  Sanding at this stage will wear out the sandpaper and put a considerable amount of dust in the air.

So that calls for more planing!  I have never used a plane before so I asked for a planing lesson.  The 'trick' is to approach the wood at an angle and when the blade catches continue on the angle keeping the back end of the plane off the wood.  If the rear of the plane rides on top of the wood your cut is very shallow if you get a cut at all...  As with everything practice is needed.

We were not able to get to the Kerfing but are very close.  Some more planing was needed to correct the mistake we had made earlier and we just started sanding.  So another 20-30 minutes and we will be ready to apply the Kerfing.

Here is a picture of one of the students and Robbie applying clamps to the Kerfing using a "high tech Kerfing clamp" (clothespin w/rubber bands wrapped around it).  The Kerfing is sort of like a wooden 90 degree shelf that lines the front and bottom of the guitar and is what is used to glue the top and bottom wood to.

Next week we will finish our planing, sanding and radiusing, apply the Kerfing and start to prepare our back side for mounting.  General feeling this week was excitement as we started to see the guitar take shape and of course some disappointment as lessons learned always carry a little pain with them.  But overall we are very pleased with our progress, have learned a tremendous amount in a short period of time.  We are always a little disappointed when the clean up bell comes.