Phil Stevens

r ransom wrote:I would also like to learn more about the bridge and tail piece.  Why is it like that?

Is it designed for specific music style?

What is the advantage over a regular acoustic bridge we have with pegs to hold the strings?

It's a design that puts the tension of the strings onto the shell of the guitar via the tailpiece instead of depending on a bridge affixed to the top. This means the top doesn't need as much bracing because the forces are applied to a structure that can take them relatively easily. The downside is the angle or deflection of the strings as they pass over the saddle is very slight compared to a top-mount bridge. This transmits less of the vibrating energy of the strings into the top and makes for a quieter tone with less "attack" or definition. One way to make up for this is with an arched top, which borrows some tricks from the physics of violins and similar instruments.

I also like the two-bucket system, plus if you fill the liquids bucket with biochar you solve the smell issue and end up with fantastically charged biochar when it's time to empty it.

r ransom wrote:
What would we look for to tell if the problem is with the neck and not the body?

I tried taking the tension off the strings and observing.  It all goes flat with the tension off.  With tension on, the body sinks in at the bridge/nut (is it still a bridge if the strings don't attach to it?)  Above the sound hole where the neck is, everything appears to stay flat (the same as without tension) , but I didn't know how to measure this except by looking.

I couldn't see any curvature to the neck with or without tension.  But maybe there is a better way to check.

I'd recommend checking it out with a straightedge that's at least as long as the guitar. With the strings tuned up, place the edge along the top and fretboard, and note how close everything is to being flat and true. Ideally, the saddle and nut should touch and the distance to the frets should be consistent with the tiniest bit of a concave profile. Repeat this with the strings loosened.

It sounds like the bridge caves in under tension and creates the dished out area in the top. If the neck set is bad, you would probably see the improper angle whether or not the strings are at pitch. So what the guitar most likely needs is some remedial bracing, like an X under the bridge.

It's certainly possible that this guitar does not have broken or popped braces and that the problem is with the set of the neck. If there's a truss rod, it might be able to be adjusted. If there's not, the only thing for it is to remove and reset the neck to get a better angle. Have a look at the heel joint. That's where the neck is fixed to the body. You might be able to see if it's coming apart there.

This is almost always a symptom of broken (or insufficient) bracing. If you can get a mirror in there, or a little USB endoscope with a light on it, you can look at the underside of the top in the area of the bridge. Sometimes it's just a matter of regluing a popped brace. If it's broken, then replacement is on the menu. If the top is dished in front of the bridge (or bowed up behind it) and you're certain that the bracing is firmly attached, then they're just not up to the task and replacement is the only long-term fix. You can always try lighter strings that exert less tension, but the tradeoff will be higher action since the bridge sits up more than it should.



This video shows how a luthier does it, using a clear top so you can see what's going on. He's got some cool ninja tricks like the special saw blocks he uses to clean out the old glue, and the steel pieces held on with magnets to keep glue from going where you don't want it.

Every time I see examples of the rock and gravel at Wheaton Labs I just get jealous. All that beautiful, angular shattered material that interlocks and knits together when it's put in place. I'm on what used to be the riverbed and everything here is rounded. It's good hard rock, but it packs about as effectively as ball bearings :-(

I had a lovely gentle Black Orpington rooster named inigo Montoya. His father, on the other (five-fingered) hand, attacked my son in the paddock one day, and so the tale is told.

A while back I bought 100 used coffee sacks. I think they cost me $20 plus shipping and it's one of the best micro investments I ever made. Sometimes when I got out a fresh bag there would be a handful of green coffee beans left in the bottom, so I got to wondering about how to make the most of those.

I got out my cheapo heat gun and a stainless steel colander, and went to work. The results were impressive, and I learned a few important things:

1. Always do this outside. The smell is not all that nice thanks to the skins coming off the beans and burning.

2. The skins fly around and go everywhere.

3. Keep the beans moving around and watch for the oils to accumulate on the surface as well as the colour. This is how you control the darkness.

4. Don't try to do too much at once. My best batches were a couple of handfuls, maybe a cup at most.

John Suavecito wrote:Phil,
I have a lot of clay soil where I live. Would it be helpful to add some clay soil to the wood stock before I start the biochar burn?  The functionality sounds like a good way to improve soil fertility.
John S
PDX OR

Yes, this is a great idea. If you're ambitious, try making a clay slurry and soaking a batch, then letting it dry out prior to a burn.

Jay Angler wrote:

Does the article say how long the ~300 degree biochar lasts? One year - 50 years - 300 years? Because I consider it a renewable resource on my land, if the low temp stuff I can make easily and that helps my soil, can last even 10 years (and I suspect most of it lasts longer than that), I think I'm still ahead so long as I keep making it.

Lower-temperature biochars oxidise and degrade more quickly than high-temperature ones. But it's like a long ramp, not falling off a cliff. Let's say we had two batches of biochar made from the same type of wood, one produced at 300 degrees and the other at 700, and put them into soil.  The total carbon stored starts off at 90% for both types, and if you sample at 100 years the 300-degree batch might be down to 60% and the 700-degree batch is 85%. At 200 years they're at 50% and 80%, respectively, and at 1000 years the numbers might be 20% and 60%.

Aside from giving up some of its carbon, the pore structure of biochar more than a few decades old gets plugged, so if you've got plenty of feedstock and like the results, there's a good incentive to keep topping it up. The terra preta soils probably developed over centuries at least, and deposits of pyrogenic carbon in ecosystems with recurring fires often go back tens of thousands of years. Really old biochar is called inertinite and is found in coal seams where it's been preserved for as long as 300 million years.