Question about binding on Martin

[murrmac123]

You're probably right, Charles. I was recalling a discussion with Mario Proulx a very long time ago on the MIMF in which he advocated the method I mentioned.

I think in that case it was a relatively narrow binding coupled with a wider purfling ....I should not have extrapolated from that to generalize that it was the preferred method in all cases.

[Rodger Knox]

Originally Posted by murrmac123

You're probably right, Charles. I was recalling a discussion with Mario Proulx a very long time ago on the MIMF in which he advocated the method I mentioned.

I also scrape the sides to the bindings, also from a discussion with Mario Proulx on the MIMF, maybe the same one.

[mirwa]

Originally Posted by Todd Yates

Different circumstances.

K.

In this trade one is always learning, be that with 1 yr under your belt or 50 yrs under your belt, if someone is managing to do something differently than I, I am always curious as to the hows and whys.

Appreciate the reply you gave.

Steve.

[mirwa]

Originally Posted by charles Tauber

I'm not aware of anyone, let alone most, who chose to level the sides to the binding.

Concur.

Not a single mainstream manufacturer I know off, does this. I can envisage some custom builders possibly doing this, I do not understand the reasoning behind doing such a labour intensive process.

A properly routed binding channel requires no fancy work to improve it further.

Imagine doing laminated sides and going in your own head, I will just sand the sides down through the lamination's so I can get it to an even height with my binding.

Even taking a solid side, scraping it at an angle across the width of the guitar defy's logic.

Steve

[John Arnold]

minutely differing thicknesses along the binding can be instantly detected by the eye,

Not if the binding edge is properly rounded (like a Martin). Rounded edges are much more friendly, both for the picking arm and the body.
Unless I missed it, the OP did not indicate whether the binding was higher than the wood. If so, I would be checking for loose binding, particularly in the waist. The normal occurrence is that the plastic will shrink over time. This means the binding ends up below the surface of the wood. Shrinkage is also why loose binding pulls away at the waist.
Also note that in a fimished guitar, leveling a step in the binding will remove finish, which may require adding more finish. On most guitars, finish is applied over the binding.

[funkymonk#9]

Just to add my own 1 cent, going to Luthier school and building acoustics, we were taught to route the rabbit to .010 oversize width and sand/scrape the sides down to the binding.

[charles Tauber]

Clearly, some people do chose to level the sides to the depth of the binding, rather than level slightly proud binding to the level of the sides.

[Tlon]

Thank all for your help and advice. This has been a very fascinating and instructive thread for me.

Originally Posted by John Arnold

Unless I missed it, the OP did not indicate whether the binding was higher than the wood.

The best way I can describe it that it's as if the routed channel was not deep enough in those spots or if too much glue was put down and it just pushed the binding out a bit when it dried. The binding protrudes just ever so slightly. Not easily visible to the eye, but I've tried to capture it in a photo below. Its noticeable if I scrape my finger across it, up or down. This is the case at both the top and bottom of the guitar in the same spot in the valley between the upper and lower bout. Otherwise, it seems stable, no give when pressed, no looseness, no separation from the sides of the guitar.

On the top-side, there no gap (as far as I can tell) between the binding and the bottom of the channel where the bottom of the binding sits on the channel ledge (short part of the L shape of the routed channel).

On the bottom-side, there is a very, very slight (~.5 mm) gap where I can see some glue between the wood, but I have to look with a 3x magnifying lens and a bright flashlight to see it.

Mostly, it's not visible just that I can feel it. I'm just concerned about the long-term potential if the binding is expanding or separating, which doesn't seem to be the case to my very, very, very untrained eye.

On the top face of the guitar, the binding seems to be perfectly level and smooth and meet the wood with no gaps or protrusions.

On the bottom face of the guitar, the area in the valley between the lower and upper bouts at the bottom-side does have a little edge to it, but it's very faint to the touch.

Again, to my very untrained eye, it strikes me as more of production quality issue, but I am very aware that I don't know enough to determine if something is expanding, separating, or otherwise a problem.

[Tlon]

In case anyone is interested, I did take the guitar to a luthier I trust and it was clear to him that the binding was coming loose. Thank you all for your input and advice.

[Jimmy Caldwell]

Originally Posted by charles Tauber

Not to nitpick, but I'm not aware of anyone, let alone most, who chose to level the sides to the binding. It's a lot of work to do what you suggest.

I've been doing it that way for about the last dozen or so years (60+ guitars). The amount of the sides that I leave proud of the binding is very small - only a couple of thousands of an inch and takes very little time with a sharp scraper to bring the sides flush with the binding. It's a process that needs to be done anyway to insure flat sides and it does make a difference in the appearance of the binding job.

[mirwa]

Originally Posted by Tlon

In case anyone is interested, I did take the guitar to a luthier I trust and it was clear to him that the binding was coming loose. Thank you all for your input and advice.

, nothing beats a set of local eyes.

Steve

[John Arnold]

The best way I can describe it that it's as if the routed channel was not deep enough in those spots or if too much glue was put down and it just pushed the binding out a bit when it dried. The binding protrudes just ever so slightly.

The binding was sanded flush before the finish was applied. Further sanding of the finish also assures that it is flush when it leaves the factory. Since it is no longer flush, that means that something happened after the gutar was finished. I outlined the two possibilities.