Friday, May 29, 2009
There is actually both a geometrical and a mathematical way of figuring the distance between each fret. I can't show you the geometrical way, and I'm not sure you want me to try to explain the mathematical way, but for those with pocket protectors, here it is: take the scale length (the distance from the front of the nut to the front of the saddle) and divide it by 17.817, and that gives you the distance from the nut to the first fret. Subtract that number from the scale length, and divide by 17.817, and you get the distance from the nut to the second fret. Keep doing this for as many frets as you plan to have.
With a calculator it's not that hard, but unless you are using an odd scale length there's no need because someone's already done the math for the most common scale lengths. I'm using the most common scale length for both dreadnought and OM guitars, 25.4".
But here's what you get: the distance from the nut to the first fret is 1.426", from the nut to the 2nd fret is 2.771", 3rd fret 4.041"...you get the picture.
How exactly do you measure 2.771"? Even if you round to the nearest 1/64", you still get 1 27/64", 2 49/64", and 4 3/64". When you're measuring in 1/64ths of an inch, it's easy to be off when measuring and marking. A less-than-sharp pencil can mess you up.
And fret spacing is pretty important if you like things like playing in tune.
For guitar #002 I just ordered a pre-slotted fretboard from LMI, but over the winter I was able to get the tools necessary to do it myself. This is the same system that LMI uses and that we used at Vermont Instruments when I built #001.
I spent a good part of yesterday and today building the table saw sled for the slotting system. Here are a couple of pictures of the sled seated on the table saw.
It's made of 3/4" MDF (medium density fiberboard--think tightly compressed cardboard) which is nasty stuff to work with but great when you need something that is absolutely flat and square and won't warp. In this regard it's better than plywood.
Underneath I attached two metal runners that fit in the two miter slots of the table saw.
The regular blade is replaced by a special fretting blade, which is smaller and thinner. Because it is so thin it will distort when encountering the hardwoods like ebony and rosewoods that are used for fretboards, so it is sandwiched between two thick metal plates.
At the heart of the system is an acrylic template which has notches along both edges corresponding to the fret positions of two popular scale lengths, 24.9" and 25.4". I mark the center line on my ebony fretboard and, using double-stick tape, tape it to the template so that it matches the centerline of the template.
Installed in the fence is an indexing pin which fits into the notches.
By holding the template against the fence and pushing the sled over the saw blade, I get a kerf cut into the fretboard that is the perfect width for the fret wire.
Before I can do that I have to know what depth to cut the slot. This is complicated by the fact that the fretboard is going to be radiused i.e. it will be slightly domed across it's width. If I just cut to the depth of the fretwire tang (the part under the fret that gets hammered into the fret slot), then when I radius the fretboard the slots will be too shallow at the edges. It's better to be a little deep in the middle than shallow at the edges. But how to figure this out?
Luckily I have a pre-slotted and radiused fretboard for a 24.9" scale length, and I find that a piece of posterboard fits perfectly in the slots. I cut a small piece of posterboard and use a straightedge to make sure one side is perfectly straight. I insert this edge into one of the slot and, with a very sharp pencil trace the outline of the fretboard. I use a razor knife to cut along this outline, and now I have a guide for how high to raise the saw blade. I just hold it over the blade with the two outside edges resting on the table, and raise the blade until it touches the highest point on the gauge.
Boom! Now I'm ready to slot the fretboard. The first notch cuts a slot which will be the front of the nut. Then I move the template to the next notch, run it over the blade, and repeat for twenty frets.
When I'm done, I have a slotted fretboard.
Took me several hours from start to finish, but for every guitar after this it will be a thirty minute job including switching the blades out and cleaning up.
And I can now say that I did everything on the guitar myself.
Thursday, May 28, 2009
When I first received the wood for #003 everything looked great. A couple of weeks ago I was showing the zebrawood to someone and noticed what looked like a crack near the top.
Sure enough, there was a crack, and it went all the way through the wood. Then I noticed that there was a corresponding crack on the other half. Here's the crack on the right half:
Not so bad, but here's the one on the left half:
Very noticeable. When folded the two pieces back on each other they match, so it's clear that this is a weak area of the wood, and in the 2-3 months since I received it, this weak area gave way. When I flipped the left side over, the crack looked like the one on the right side, and vice versa. In other words, both boards had a side where the crack wasn't so bad and a side where it was really ugly. Problem is, in orienting the sides bookmatched, one board always had its ugly side up.
I thought maybe I could orient the pattern such that the ugly crack fell outside of the cutaway area, but that didn't work, and the mild crack is just mild in comparison to the ugly side; it's still noticeable.
Since the cracks go all the way through the wood I wasn't able to sand through to solid wood. I'm stuck with a couple of cracks in the back.
This was on a Friday late in the afternoon, so I call the supplier, Luthier's Mercantile International, out in California and talk to Chris, the sales manager. I explain the problem to him. He says that when they get cracks in wood that they use super glue to solidify the cracks and keep them from spreading. If it's just a hairline fracture with minimum separation, after sanding it's invisible. But since it's been a few months since I receive the wood there wasn't much they could do. I told him that I would give it a shot but I was skeptical because there did appear to be separation and because the crack went all the way through. I asked him if I could buy just another back set if that didn't work, or would I have to buy a whole back/sides set. He said that it would be difficult to break up a set, but if need be he would check and see.
So I tried the super glue and sanding, but it didn't work. Well, more accurately, it solidified the crack so that the two back pieces are structurally sound, but it actually made the cracks more noticeable and ugly. It's simply a cosmetic issue, and it's on the back where it won't be seen that much--but the more I thought about it, the more unacceptable it became. I couldn't ask Clark to accept something that I felt just didn't look right.
By this time it's 5:30 out in California and LMI is already closed for the weekend, so I just have to live with it for a while. Clark comes over the next morning to makes some choices on binding materials, and I can't bring myself to mention it to him. I decide that on Monday I'll call Chris up and order a whole new back/sides set. Since the original set is structurally sound I'll go ahead and use it for some future guitar and either keep it myself, give it away, or sell it on eBay with full disclosure on the cracks.
Monday afternoon I call Chris at LMI and tell him that the super glue fix worked but just doesn't look good, so I'm going to need to replace it. I ask him if he thinks he can just sell me the back, and he says yes, and then surprises me by saying that he's going to replace it at no cost.
Chris at LMI is the MAN! And I tell him so.
He has me email him a picture of the original set so he can make sure the back he picks is a good match for the sides. The next morning I get an email saying that he has found a good set for me, and after he gets it sanded down to proper thickness, he'll send it out.
Well, it finally arrived yesterday, and it matches the sides quite well. Here's a picture of the new back:
You'll notice at the bottom of each side there is a knot where there used to be a branch. There's actually a small hole there, but this area falls outside of the guitar shape and will be cut off and thrown away, so it doesn't matter.
I thought about putting these edges together with the knot at the top:
The knot would still fall outside the guitar shape, but at the very top of the back there would be that very nice figure where the grain goes around the knot and then converges back together in the middle.
However, in this orientation the boldest lines are on the outside and a lot of them would fall outside the guitar pattern. Other than the converging grain lines at the top the grain in the middle is rather homogenous, so I decide that the other way is the way to go. Besides, Pam says that those converging lines of grain "look like a butt-crack. You can't have a butt-crack on your guitar."
OK, she's right, but I think it's clear where Austin gets his.
Clark, I know you are reading this so if you want it the, ahem, butt-crack way, give me a call.
It will be a very striking and beautiful back. The braces for the back have already been cut, so I'm going to join the back as soon as I can and brace it as soon as the humidity allows--looks like I may have to wait until Saturday--and hopefully that will stabilize the wood and prevent any cracks from developing.
Someday I'll use the original back for something. I'll just order some sides to go along with a top that I didn't use because I didn't like the way the soundhole turned out, and I'll have a decent guitar with a couple of "character marks." Sell it on eBay, give the money to Water4Christmas. Yeah, that sounds like a plan.
Chris at LMI. I'm tellin' ya, he's the MAN!
Wednesday, May 27, 2009
If you listen to it and follow it's direction, it will yield willingly to you, like it wants to become something useful or beautiful. Pay no attention to its qualities, or ignore what it is trying to tell you, and each saw stroke, each chisel stroke, each pull of the rasp becomes a struggle. Like a recalcitrant child it won't give you what you want seemingly out of spite.
Give it the respect it want, and it accepts the push of the plane across its surface and willingly produces the fluffy curls that are almost too beautiful to consider trash. You feel the neck give way to a razor sharp chisel or well-tuned plane. You don't feel much from pushing a board across a table saw except perhaps relief when you see that you still have ten fingers.
Perhaps the most pleasurable part of building a guitar is the shaping of the neck. Famous guitar picker and bulding Wayne Henderson uses a power belt sander to shape his necks, but most custom builders that I know use hand tools--chisels, rasps, scrapers and spokeshaves. This is the process that most makes me feel like a craftsman; I'm taking a rectangular block of wood and sculpting into something that just begs to be held in your hand.
It takes skill to use hand tools, and most of the skill comes through experience. Lacking the experience and the skills that come with it, I turn to power tools to give me the precision that a fine instrument requires. Sure, sometimes it's just a matter of time. I have the skills to dig the truss rod channel out using a chisel, and this isn't something that requires a lot of precision, but it would take a few hours and a lot of sweat to accomplish it. And there is someone anxiously waiting to get their guitar. Now, I've told the people who have commissioned guitars from me (both of them) is to not be in a hurry, because I'm not. I can build it good, or I can build it fast, but I can't do both. Nonetheless, I have to respect the time issue. It takes a few minutes to set up the router table, rout the truss rod channel, and clean up. Less than an hour, and I'm on to something else.
My goal, however, is to build a guitar that looks great, plays great, and sounds great, and to do all three of those things requires absolute precision in certain areas, precision that my skill level with hand tools doesn't yet allow me to achieve. The scarf joint, for instance, can be cut with a back saw, then smoothed and leveled with a block plane, scraper, and sandpaper. But I'm not that good with a backsaw, and to overcome the resulting cut requires a great deal of planing and scraping--and a certain amount of frustration--before I am able to achieve a smooth and level joint ready for gluing.
Using a table saw and a special jig that I built myself, and it took me an hour from cut to glue up.
That was fun. I have enough frustration in my life. I'll always do it this way. I'm not a romantic when it comes to hand tools.
But thinning the the top, that's different. I realize that I neglected to mention that I was doing more than thinning the top--I was voicing it. After I first joined to bookmatched halves, I held the top between the thumb and forefinger of my left hand and tapped it with the middle finger knuckle of my right hand, and listened to the resulting tap tone. I haven't tapped enough tops to really know what I'm listening for; I'm just building up an internal vocabulary of tap-tones. At first, it's just a dead thump. After each round of planing I tap it again, holding it in different places, listening to the change in tone, listening for the lows, the highs, for how long the tones sustain and how fast they decay.
This is organic, and even if I could do it with a power tool like a wide belt sander, I don't know that I would. I want to be in touch with the wood during this process. I want to hear when it first makes a whoof sound when held by the edges and shaken, and when the tap-tones last slightly longer. Each piece of wood is different, and so these things happen at different thicknesses. It would be easy to just bring each top down to a uniform thickness and be done, but that doesn't respect the story that the wood is trying to tell. It's a feel thing. You know it when you hear it. Well, I don't, not yet, not thoroughly. But I'll never know it--feel it--if I don't listen, if I just bring every top down to a uniform .115".
So the bottom line is I will use power tools when a certain amount of precision is required for great sound, great playability, and/or great looks, and I will use handtools when I most need to listen to what the wood is saying.
Because the goal isn't to crank out as many guitars as I can, or to be able to say that my guitars are completely made by hand using hand tools. The goal is to create art--visual art, musical art, and tactile art. And my belief is that if a player is creating music on a beautiful instrument that they love to hold and touch and play, the music they create will truly be art as well.
Because it's all about the music.
Tuesday, May 26, 2009
Not low fat at all, but definitely high in the flavor department. I served them to our church staff one time, and they all went crazy.
You gotta try these. If fixed according to the recipe they are not hot at all. I like hot stuff, so I put hot salsa and jalapenos, but if you are more delicate then you will still like these.
Monday, May 25, 2009
My plan for the rest of the day was to cut out all the braces, shower, run some errands with Pam, then go to a cookout with her rescue squad team. (Monday is her squad night). Then I would come home and at least get the X-braces glued onto the top.
Got all the braces cut, but it took a few hours. Measure twice, cut once works great, but all that measuring takes time. The braces are made out of quarter-sawn Sitka spruce; quarter-sawn means that all the grain runs vertical with no run-out so that the braces have the strength they are designed to provide. Each brace needs to be cut to length, height, and width, and that's a lot of measuring, setting up the tablesaw and/or bandsaw, and cutting.
But I got it done, took a shower, and Pam and I headed out around 4 p.m. It was then I noticed the overcast sky. Felt like rain. Pam said, yeah, we're supposed to get some rain.
If rain is coming, that means that the humidity is up. And if the humidity is up, I can't glue any braces. They lock the top up, preventing or at least severely limiting it from expanding or contracting.
Like would happen when wood goes from high humidity to normal humidity. As it dries, in contracts. If the braces are glued in high humidity, then if the guitar is ever in an extremely low humidity environment, there is a very good chance it will crack. Likewise if they are glued under extremely dry conditions.
Wood likes it in the middle. 45% is optimum. Nothing less than 40% or higher than 60% is acceptable.
When I get home from the cookout, the humidity in the garage is 67%.
And it's 8:30 p.m.
I turn off the lights. Live to fight another day.
But that day may be a few off. It's supposed to rain the next two days, with 50% chance of thunderstorms on Thursday. It may be Saturday before I can glue any braces.
Oh well. There's other things to do.
I can leave it a little thicker in the upper bout as well, since this is an area that has less of an effect on sound than the lower bout yet is subject to some stresses in that the fretboard which extends over this area is being pushed down into the soundboard.
Oh, and there's a big hole in the middle of this area. That tends to weaken things as well.
I track my progress I use a thickness gauge mounted on a plywood holder with a deep neck.
I plot the thicknesses of various areas and note which areas need a lot of work and which are almost there--and which to stay away from.
.130" is good for the middle--I'll bring it down to .125"--but too thick for the edge, as you can see at the top. I work to bring all the edges down to about .110" It's a lot of clamp, scrape, unclamp, draw the body shape, measure, and repeat, but after about an hour, I have everything where I want it. I do a quick sanding of the entire top just to clean it up.
Now it's time to cut out the soundhole. I set the top back on my workboard and use the circle-cutting jig to cut the soundhole:
On my first guitar I signed and dated the soundhole, and decided that I would do that as a keepsake for all my guitars. I rub a little oil finish on it to protect it, and it's done. Here's the soundhole for #003.
It's mounted in my workshop with the other two.
The last thing for today is to cut the top to the shape of the guitar. I do this at the bandsaw, staying just outside the pencil line. Look, Ma! It's starting to look like a guitar!
Sunday, May 24, 2009
The top plate started out around .150" thick, more than 1/8", which is much too thick. This is the part that must be vibrated by the action of the strings, creating the air movement inside the guitar that we hear as sound. No movement, no sound. I want it between .110 and .120. I want to balance structural integrity with movement. The structural ideal would be a top plate that would be stiff and strong. It would last forever--but would have little volume and the tone would suck. Great tone and volume would require a thin piece of wood, the thinner the better, but such a top would explode under string tension. So a delicate balance is required. There is no perfect figure, because each piece of wood is different. Two pieces from the same tree could vary widely. One piece would be very stiff, whereas another of the same thickness would be extremely flexible.
Sitka spruce is very popular for guitars because it is both strong and light, allowing it to be thinner than other species while maintaining strength. Other popular top woods, like cedar, are softer and so have to be left thicker to be structurally sound.
Using a plane, I start thinning the top, checking it frequently with a thickness gauge.
There's nothing more pleasurable to use than a sharp plane. You know it's going right when you get all these fluffy plane shavings.
After getting the top down to .125-.130", I switch to a cabinet scraper, more to remove the plane marks than to remove material. When the plane marks are gone, I hit it with some 100-grit sandpaper.
Before sanding down to final thickness I need to rout the channels for the rosette and then install the rosette. This is the decorative piece that goes around the soundhole. I plan to use a three-part rosette. The main rosette will be some paua (pronounced "pow-wah) abalone (short "a" followed by "baloney") shell strips which will be sandwiched between two thin pieces of purfling composed of thin lines of maple-ebony-maple. Inside and outside of this main rosette will be thin circles of black-white-black purfling. You'll see what I mean in a second.
I have a a plywood workboard into which is drilled a 3/16" hole. A metal pin goes into that hole, which is part of a circle-cutting jig to which my Dremel tool (essentially a small hand-held router) is attached. I lay out where on the top the soundhole will be located, then drill another 3/16" hole at the soundhole center.
Since the abalone shell is preshaped into a fixed diameter I have to locate everything off the inside and outside diameter of the shell. In the following picture the circle is the inside diameter of the shell. Then on the center line I have marked the top of the soundhole, and the inside and outside diameters of the two B/W/B purflings and the shell sandwich.
The purflings are 1/16" wide, and I happen to have a 1/16" bit, so I put that in the dremel. The areas to the left will be covered by the fretboard, so I test everything in this area before making the full cut. I make small cut in the neck area for the inside purfling and use a small piece of the purfling to test the fit. Perfect.
So I rout the entire circle and dry-fit the purfling:
Fits great, so I repeat the process for the outside purfling. The main rosette is trickier since I'm routing one wide channel but then fitting three separate pieces in. At first it was too tight, but the circle cutter allows for micro-adjustments, and I'm able to creep up on a perfect fit. After dry fitting everything, it's time to glue it in. I start with the two thin purflings, running the bottom edge through some wood glue then pressing them into their channels. They fit perfectly but just to make sure I use a small baking roller to make sure they are fully seated in their channel.
There's a neat trick for the main rosette. Since the shell is delicate and easily breaks, I don't want to try to work around forcing a sandwich into a tight channel while working against the clock (the glue gets tacky within five minutes). So I substitute a length of white Teflon that is the exact width of the shell. The glue won't stick to the Teflon, so after everything else is dry I can pull the Teflon out and easily place the shell between the two W/B/W purflings. This is what it looks like all glued-up.
The maple blends into the spruce so that it appear that there are two thin black lines surrounding the Teflon.
I put wax paper over all this, a plywood scrap on that for even pressure, and a three cam-clamps to make sure everything stays seated. I let this dry overnight.
The next day I pull the Teflon out to see how the shell fits--and it fits perfectly. (I'm saying this so often that it's getting scary.) I use some white glue (most of us know it as Elmer's Glue) because it drys clear, and fit the three pieces of shell into the channels.
Once again this gets an overnight dry, but mainly because I did it late at night. A couple of hours would have been sufficient.
The next morning I use a cabinet scraper to scrape everything flush with the surface of the top, followed by some sandpaper to get everything smooth.
Here's the finished product:
It looks even better in person. And under a finish the abalone really sparkles.
I measure the width of the truss rod, divide that in half, and mark that distance on either side of the center line. I then set up my router table to rout the channel. Since the bit isn't as wide as I need the channel to be, I set it up so that it cuts to one of the outside lines, make the cut, then reset it to rout the other half of the channel.
Cutting the full depth would overload the router motor and could possible also result in blowing out a large chunck of wood, so I set the depth to just take off a smidge.
Each time I measure the depth with the actual truss rod, cutting to both line, checking the depth, resetting and doing it all over again. I want to leave as much wood as possible while making sure that the truss road is close to the surface.
Here's the truss rod in the channel.
Maybe a smidge deep, but it's ok. I'll put some silicon caulk in the bottom to keep the rod from rattling, and that will take up some space. (A loose channel will cause a rod to rattle when it's natural resonance frequency is played. It will actually vibrate in sympathy to the frequency, so I want a nice tight fit.)
OK, now is actually when I glued the veneers onto the peghead. The next morning I unclamped everything. Looks good. Next I cut the end of the veneers to a 90 degree angle to the neck (not the peghead) using a 15-degree block as a saw guide. This is an important surface since the back of the nut will bear against it.
Next I screw a template of the headstock shape onto the back of the peghead, and rough cut it at the band saw.
Then I set up a router bit with a bearing to ride agains the template, and with the veneers face down, shape the headstock.
And there it is. I'll put some decorative binding on the headstock, but that's for later.
This is all I want to do on the neck for now. I want to wait to cut the tenon until the body is done because I need to make sure there is a correct neck angle at the body joint--the neck tilts back from the body 1 to 1 1/2 degrees, but I won't know how much until I can attach the neck to the body and measure the gap at the bridge. You'll understand when it rolls around. I also need to wait to shape the neck until at least the fretboard is glued on, and there's much to do before that happens.
So it's on to the soundboard.
The tenon which will hold the neck onto the body will be 15/16" long, so I mark this from the 14th fret position and square another line.
Now I know where to attach my end block. While the jointer was out I flattene one face and squared two sides to that face. I mark its center line and line it up with the center line of the neck, and it's ready to be glued.
I do this Thursday morning before work so that it will be ready to be unclamped when I get home later that day. After unclamping everything and making sure that it didn't slip out of place while being clamped, I then cut it to rough shape on the bandsaw.
Now it's really beginning to look like a guitar neck.
Next it's time to glue the veneers onto the headstock. These are thin sheets of wood that are mainly decorative, but the main veneer strengthens the peghead and makes it less vulnerable to cracking if the guitar is dropped.
The main veneer is a piece of ebony, and sandwiched between that and mahogany headstock will be a very thin sheet of maple. When glued this maple veneer will appear as a thin line all around the edge of the peghead.
This is a pretty simple operation. I use a couple of wood cauls to protect the mahogany and ebony from being marred by the clamps, and wax paper to keep the glue squeeze-out from gluing the cauls to the neck.
I do a dry fit, then spread Tite-Bond first on the maple veneer, placing that on the peghead, then on the ebony, which then goes on the maple.
Wax paper, cauls, clamps, and the end result is this mousetrap:
This has to glue overnight, so I'm done with the neck for now.
But when does the church remember those who gave their lives for the cause of Christ? Who recognizes them? In the 21st Century Christianity has averaged 160,000 Christian martyrs each year. We are just shy of the halfway mark of 2009 and already there have been over 176,000 Christians murdered just for being Christians.
We don’t see these deaths. In the
Religion, any religion, allied with the coercive power of government, is a dangerous thing, including the government-sanctioned atheism of most communist countries. Government neutrality toward religion, neither promoting it nor interfering with it, is the only way to make sure that not only are there few Christian martyrs, but few Hindu, Buddhist, or Islamic martyrs. (And by the way, a terrorist is not a martyr. A martyr is a victim of violence, not a perpetrator of it.) There is certainly a price to be paid for government neutrality. A person of faith employed by the government has to assume a neutral stance toward religion while functioning as an employee. If that means that they cannot proselytize while on the job, that is a small price to pay for the freedom to worship freely in their churches, synagogues, mosques, and in their homes.
I have nothing but admiration for those Christians who worship Christ in the face of persecution, knowing that to do so might cost them their jobs, their freedom, even their lives. As we remember those who gave their lives for our country, let us also remember those who, for the cause of Christ, also gave “the last full measure of devotion.”
Thursday, May 21, 2009
The same is true spiritually. Survival mechanisms are self-centered, but to develop the spiritual life requires us to develop a strong sense of other-centeredness. Jesus said to love God with all our hearts, minds, souls and strength, and our neighbors as ourselves. This isn't wholly alien to our natures, but it certainly goes against the grain of the survival instinct.
Paul talks about bringing the body under control through disciplines in 1 Corinthians 9:25-27: "Athletes exercise self-control in all things; they do it to receive a perishable wreath, but we an imperishable one. So I do not run aimlessly, nor do I box as though beating the air; but I punish my body and enslave it...."
Punish the body, enslave it. Harsh words, but that is what athletes do. They put their bodies through punishing exercises in order to get it to do what would otherwise be impossible. They are bringing it under control.
The early church developed practices to bring the self-centeredness of our bodies (and our minds) under control. Many if not most of these practices, called spiritual disciplines, are not found in Christianity alone but can be found in various forms in all religions. But just because Buddhists meditate does not mean that there is not a place for meditation in a Christian's life. It's just a matter of orientation.
Jesus tells us to love our enemies. That sure goes against our survival instinct. It's not natural. What's natural is to want to hurt our enemies, to kill them if need be. So how do you love an enemy. Well, Jesus said to pray for them. It will be hard at first, and your prayers might not be all that benevolent, but you discipline yourself to do it anyway. Praying daily and earnestly for a person you consider to be your enemy will make it harder to hate them, and not-hating is a first step toward loving.
Prayer as a spiritual discipline makes you more aware of God. And when you pray for others, you by definition are more aware of them. It's easy to ignore children dying of starvation if you never think of them. Make them a part of your daily prayer, and you will think of them. And they will haunt you. And you will want to help them. Whatever else that prayer might do, it keeps people and their needs on our minds.
Fasting is not much in fashion, except when trying to drop ten pounds fast. But it's purpose, among other things, is both to expose how dependent we are on gratification and also to wean us from that dependency. Brian McLaren, reflecting on a an experience of fasting, writes, "During that day of fasting, I felt and acknowledged my weakness in the face of impulses and cravings from my body."
When I call these and other spiritual disciplines ancient practices, I don't mean that they are out-of-date but rather than they are well-tried and have proven to be effective for thousands of years.
But they aren't easy. And they aren't natural. But with discipline and practice, they can become natural.
Wednesday, May 20, 2009
The edges to be glued together are only about 1/8" thick. If you put the two edges together and hold them up to a light, you can see gaps. These gaps need to be eliminated so the there is a good glue joint.
I fold the bookmatched pieces together, lining up the end grain, and use some painters tape to hold the pieces in place, and run the edge over the jointer a couple of times.
The result is a pretty good fit, but pretty good isn't good enough. There's going to be a lot of forces trying to separate these pieces, so they need to mate perfectly.
I then lay two pieces of plywood on the work bench, one 3/4" and one 1/2". I lay the pieces down on the 3/4" piece with the edge to be jointed overhanging the edge slightly, and clamp them down. The 1/2" plywood goes under the overhanging spruce top, and on top of that I place a carpenter's level. Using spray adhesive I glue narrow strips of 220-grit sandpaper onto on edge of the level, and lay the level on it's side so that the sandpaper faces the edge of the spruce.
This enables me to sand the entire length of the edge, removing any imperfections left from the jointer.
After a few minutes, the edge is nice and smooth. I hold them together toward the light and behold! No light can be seen through the edge. It's now ready to be glued.
As you can imagine, clamping two long boards together on their thin edges can be challenging, but there is an ingenius way to do it. (Obviously I didn't come up with it.)
I lay two 1 x 2 sticks on the bench top, and place three more such sticks on top, perpendicular to them.
The soundboard goes on top of these three sticks, and three more sticks are laid on top of the soundboard directly above the three sticks that are under the soundboard.
I take a 100 ft. length of cord that has a loop on one end and loop it around the far left bottom stick.
I then begin to wrap the soundboard with the cord in a figure-8 that goes around both of the far left sticks, crossing over the top one.
I do this about six times, then move to the center set of sticks, and finally to the right set, winding the cord snug but not too snug.
I then take three long 1" wide wooden wedges and one at a time place then on each top rung, with the point slipping under the crossed cords on top. Once each wedge is in place, I gently push them farther under the cords. This causes the cords to tighten, pulling the soundboard halves together tightly. The top rungs prevent the boards from buckling under the clamping pressure.
I do all of this dry--no glue. With every glueing procedure it's best to do a dry run to make sure that everything is working and fitting correctly. I'm actually able to pick up this entire mousetrap and hold it up to a light to make sure there is a good fit. There is, so I undo it all, get out the Tite-Bond, spread glue on both edges, and do it all over again.
After cleaning up any glue squeeze-out, I leave it to dry over night. The next day, I have a soundboard!