Bridge shaving

[Slight Return]

Spot on about reaming the pin holes, I'll get around to that. Just got this one together recently and wasn't sure how long I'd leave this bridge on since I'm debating about making a new bridge with a 1/4" saddle and the pin holes moved farther back to get better intonation.

My logic: Sanding the bridge top-down does absolutely nothing (directly) to lower the action.

Lowering the saddle and/or deepening the saddle slot will lower the action. All that sanding the bridge top-down does is make the saddle slot shallower (indirectly), and *necessitate* deepening of the slot to make sure the saddle doesn't tip over.

This will work.

All I'm saying is that in this method it's the lowering of the saddle and/or deepening of the slot that lowers the action, *not* shaving off the bridge top-down, which on its own doesn't affect the action at all.

Conversely, removing the bridge and sanding it down on the bottom will directly affect the action all by itself. The saddle slot and saddle itself are left unchanged; removing material from the bottom of the bridge will lower the action without adjusting anything else at all.

Both methods will work, but IMO it's much easier to work with the bridge when it's off the guitar, and much easier to maintain the profile of the bridge by sanding the bottom as opposed to the top.

I only experiment with this on my own projects, though, and in regards to this it's a moot point. I'd only ever do this for someone else if their bridge was coming up and needed me to reglue it anyway, never as a solution to high action on a guitar with a solidly attached bridge.

Only downside is I can't leave any of my guitars alone. Just started practicing some Leo Kottke and John Fahey songs again. I'm just hoping my 12 string will be in one piece for the near future, lol.

**EDIT**

Just to clarify again: yes, lowering the bridge and saddle slot and saddle will lower the action; all I'm saying is it's a matter of steps, and sanding the bridge down alone will do nothing unless you take the saddle and saddle slot down with it. When you sand the bottom of the bridge, however, you're directly lowering the action with no other steps needed (aside, of course, from cleanly removing the bridge and regluing it).

Originally Posted by Slight Return

...Conversely, removing the bridge and sanding it down on the bottom will directly affect the action all by itself. The saddle slot and saddle itself are left unchanged; removing material from the bottom of the bridge will lower the action without adjusting anything else at all.

The bridge is part of the structure, an external brace. Depending on the style of bridge, thinning from the bottom may not advisable since the wings can be thinned too much weaken the bridge area. I'd never do it on a Martin-style bridge.

[Slight Return]

Originally Posted by Todd Yates

The bridge is part of the structure, an external brace. Depending on the style of bridge, thinning from the bottom may not advisable since the wings can be thinned too much weaken the bridge area. I'd never do it on a Martin-style bridge.

This is the exact reason I decided to experiment with taking it down. Braces that are too heavy and result in an overbuilt guitar can result in a boxy tone with less volume; with the bridge being as much of a brace as any other, an external brace as you said, wouldn't overbuilding the bridge and making it thicker than it needs to be affect the guitar tonally/volume-wise? Just like overdoing the braces on the underside of the guitar?

I did some reading and got very interested in the idea of a thinner bridge. It could be placebo, but I swear the guitar sounds louder. That is probably at least partially owing to the fact that the saddle is higher now, with a greater break angle and so more downward pressure and energy transfer to the top. But the bridge itself being thinner might have something to do with that too, all on its own.

Side note: this is why customer repairs are completely different from personal experiments. I'd never do what I'm doing on my guitar to someone else's (for repairs for other people I will usually just take the bare minimum off the bridge, just getting all the junk off to prep it for gluing...basic rule of thumb is NEVER experiment on customer's guitars, EVER....only do what you know will work 100% of the time)...

On my own guitars it's another story, especially on my 12 string, which I keep tuned to C standard at the absolute highest, and a lot of times will drop to open G, open D, and even open C from there. I use a custom .012-.056 gauge set I made myself, too*, which has far less tension than standard .013-.056 heavy gauge sets, which I used to use.

*.012/.012, .016/.016, .022w/.011, .030w/.015, .040w/.020w, .056w/.028w

It's working really well now. The real test is seeing how it holds up over time, but I feel pretty confident that tuning down to C standard should take a fair amount of tension off and minimize future bellying. But again, we'll see. Always comes back to the fact that re-angling the neck is the only true solution for the action getting out of whack.

But yeah. I see bridge shaving, whether you're taking it down from the top or bottom, as more experimental and personal than anything. If we're talking about customers, that's a whole nother discussion. Personally I would just leave it alone and go with the usual "that's as good as it's gonna get" motto. In the real world, unless someone is willing to shell out the cash for a proper neck reset, 100% perfect action just isn't going to happen.

As for the wings, that's an interesting point. But I will reiterate that, especially on cheaper guitars, it's very possible that not much thought goes into bridge thickness, similarly with bracing thickness; just because it came that way from the factory doesn't mean it's ideal or necessary.

But if you value a guitar and want to experiment with stuff like this, you'd better know how to re-angle a neck and handle anything that can go wrong, because at some point it probably will, lol.

And that's the tragedy with acoustic guitars.....eventually EVERY acoustic could use a neck reset. Most frustrating thing about the instrument. Even if stability wasn't an issue, your bridge and saddle can only come down so much.

Taylor's done a decent job of addressing this since they're bolt-on necks, so resetting them isn't too much harder than shimming a Strat neck.

Love my 12 string to death, and am loving where it is now, but it's a set neck, like most acoustics. We'll see in a year or so if the thinner bridge is enough to hold down the fort in C standard.

If not, well, more adventures and headaches and lessons learned for the future, nothing new

[Stony32]

Originally Posted by Slight Return

Sanding the top of the bridge won't do anything for the action. It'll just make the saddle slot shallower and force you to sand your saddle down to make sure it doesn't tip in the slot.

In other words, it just puts you back at square one with no change in action whatsoever.

You could either try deepening the saddle slot, or removing the bridge, sanding the bottom of it down, and re-gluing it. Sanding the *bottom* of the bridge will lower the action.

The OP wrote, "The saddle on the bass side is flush to the bridge..." Shaving the bottom of the bridge won't resolve this. In fact, doing that alone will reduce the break angle further.

[Silly Moustache]

Originally Posted by PTC Bernie

Shaving the bridge is always a stopgap measure. Whether its because the guitar isn't worth the cost of a reset or the owner just wants to get a couple more years out of it, it's still a band aid approach.

Some guitars handle it better than other. 70's Guilds usually have very thick bridges and you can get away with shaving and still have a decent amount of bridge left. Other guitars, not so much.

The bottom line is that the neck is moving and that eventaually needs to be dealt with.

What the man said.

[MC5C]

I agree that shaving a bridge is a stop gap measure, but in the same way that resetting a neck is a stop gap measure, refretting is a stop gap measure, building a guitar in the first place is a stop gap measure. It's an adjustment, not always a repair, and an adjustment in response to the natural movement of the guitar body and neck over time. Many top name luthiers have said that they will shave a bridge on a new guitar or on an older guitar if the result will be in a range of height that they consider "good". The geometry of the guitar will tell you which adjustment or repair is best, leaping to a neck reset when the bridge is over-height (which the OP's guitar certainly seemed to me, from a picture). At the end of the day the bridge and saddle are there to put the strings a certain height off the top plate of the guitar, and there is a range of acceptable height. If the bridge can be adjusted by shaving to put the top of the saddle at a good height, with good action, good string break, and save the ultimate neck reset for another decade, then I am all in favor of a bridge shave. At the end of the day I see a bridge replacement as not much more intrusive than a neck reset, installing a truss rod, replacing a fret board, repairing cracks, changing a pick guard. It's a natural part of the life of many instruments.

[Slight Return]

Originally Posted by Stony32

The OP wrote, "The saddle on the bass side is flush to the bridge..." Shaving the bottom of the bridge won't resolve this. In fact, doing that alone will reduce the break angle further.

Shaving the bottom of the bridge will not affect the break angle at all in any way. The break angle would remain exactly the same; you would simply have lower action.



Break angle is dictated by the distance between the string's contact point on the saddle and its contact point on the bridge, both in terms of the actual height of the bridge in relation to saddle height, and any ramping/slotting and bridge pin hole placement that affects the string's distance from the saddle.

Shaving the top of the bridge will increase the break angle by increasing the distance between the string's contact point on the top of the bridge and the contact point on the saddle. At the same time, however, you are making the saddle slot shallower, and will need to either file or rout the saddle slot deeper to keep the saddle from tipping.

And unless you cut a new, higher saddle, or shim the current saddle, you will end up with the same exact break angle as before, because deepening the saddle slot = lowering the saddle height. So effectively the ratio of bridge to saddle height would end up being exactly the same; you'd just have lower action. No change in break angle.

When you shave the bottom of the bridge and re-glue it, you can simply cut a new, higher saddle, or shim the current saddle, without having to touch the saddle slot at all.

And installing a new, higher saddle, or shimming the current saddle, will increase the break angle and downward tension on the top.

You're accomplishing the same thing in both scenarios. Just different ways to skin a cat. Shaving the bridge from the top will require that you modify the saddle slot accordingly, and either shim the current saddle or cut a new one.

Shaving the bridge from the bottom will require removing the bridge and re-gluing the bridge. The saddle height and break angle can be left completely unchanged, because you're not changing the saddle slot depth.

I could've done the same thing by sanding down the top of the bridge and deepening the saddle slot and cutting a new, taller saddle, but my preference was to simply remove the bridge, sand it from the bottom, and glue it back on.

I actually had to cut a new bone saddle for it because the original saddle, while the break angle was still the same, was now too low -- the strings were flat against the frets.

So now I have a nice, tall saddle with very good break angle and I didn't have to touch the saddle slot at all.

I also wanted to use hot hide glue for the bridge, to make any future changing of the bridge easier, as hide glue will come apart very easily with heat or a very small amount of steam.

[Hot Vibrato]

Originally Posted by MC5C

...At the end of the day I see a bridge replacement as not much more intrusive than a neck reset...

But, as I mentioned earlier in this thread, if you shave the bridge down, it will have to be replaced when it comes time to do a neck reset, which requires a significant amount of time and effort (at the expense of the customer if it's a paid repair job). This can be avoided if one were to just go ahead and do a neck reset when it's necessary instead of shaving the bridge down as a temporary stop-gap measure.

FWIW in the past I have shaved bridges down in the course of a neck reset at times when I felt the bridge was too tall and massive.

Originally Posted by Slight Return

I also wanted to use hot hide glue for the bridge, to make any future changing of the bridge easier, as hide glue will come apart very easily with heat or a very small amount of steam.

Actually, hide glue is more heat resistant than titebond, by far.
http://www.frets.com/FretsPages/Luth.../gluetest.html

[Slight Return]

As for the OP, and this topic in general:

Anything but a neck reset is a compromise.

Side note: I do like the idea of thinner bridges for tonal reasons, but I wouldn't mess around with that unless you know how to cut a new bridge and/or do a solid neck reset yourself. I swear my 12 string sounds louder and better, harmonics much richer, with the bridge thinned down much more and a taller saddle in place, which is the exclusive reason I did it.

I'm fine messing around with my guitars because I do all of my own work. If you have to pay a tech to do your work for you that's a much different story. If you're not planning on taking it anywhere then you should do whatever you want, if you don't care what you're doing to the value of the guitar, etc...

however, if taking it to a tech is an option, or the guitar is valuable, or you want to re-sell it, I'd just save the money and get it done right from the start.

That being said, the Taylor bolt-on system is pretty clever and certainly is much friendlier to guitar tech work. The deal with set necks is that they are NOT MEANT TO BE TAKEN OFF.

They can be taken off, of course. It's just that they're not built so they can be easily removed, which is why resetting a neck is such a huge pain and requires such an extensive amount of skill and experience to get it right.

Compare this to a Strat where neck angle can be remedied in a matter of minutes without breaking a sweat. Even a Taylor is much, much easier, and unless you're getting ripped off, getting a setup AND neck reset on a Taylor shouldn't cost too much at all, because of the bolt-on and shim system which makes resetting the neck a breeze.

For every blade of grass in the world, there's an acoustic guitar that could benefit from a neck reset.

MC5C made a good point....

Guitars have a shelf life. This is why I got into guitar work. Drove me crazy. Much more comfortable being able to do my own work, for example, refretting, which all guitars will need eventually given that they're played enough.

However, neck angle is the primary way to adjust action, and if action were a problem on my 12 string, neck angle is the first thing I'd look to.

The bridge and saddle should be at a fixed height for tonal reasons. Again, in a perfect world, the bridge and saddle and nut would all be at the PERFECT height for tone and volume and playability, and all action adjustments would be done by re-angling the neck and adjusting the truss rod to the proper neck relief, if necessary.

A beater guitar, though? Knock yourself out. I would only experiment on disposable guitars, and unless you're OK with any potential outcome, I'd find a good tech to do the job right from the start. I would never discourage anyone from trying to do their own work, because it's a lot of fun and a huge learning experience.....

...but it's kind of like stocks, lol. Only put in what you can afford to lose. If the guitar is in any way important to you or you really care about it and want to keep it for the long haul, best way to go is to find a qualified tech you can trust and get it done right from the start.

And as Hot Vibrato said....it can be hard to find good techs. Guitar work isn't easy and a lot of people cut corners. And a neck reset is the last thing you'd want an amateur to do, but if you get it done right it's well worth the cost.

[cooper59]

Originally Posted by devellis

It's not that unusual for bridges to be thicker (and thus taller) on the bass side, compared to the treble.

martin does it all the time

[Slight Return]

Originally Posted by Hot Vibrato

But, as I mentioned earlier in this thread, if you shave the bridge down, it will have to be replaced when it comes time to do a neck reset, which requires a significant amount of time and effort (at the expense of the customer if it's a paid repair job). This can be avoided if one were to just go ahead and do a neck reset when it's necessary instead of shaving the bridge down as a temporary stop-gap measure.

FWIW in the past I have shaved bridges down in the course of a neck reset at times when I felt the bridge was too tall and massive.


Actually, hide glue is more heat resistant than titebond, by far.
http://www.frets.com/FretsPages/Luth.../gluetest.html

I stand corrected. I wasn't aware of this.

And here I was MORE worried about leaving my guitar in a hot car after re-gluing the bridge with hide glue, lol.

So if the goal is a temporary mounting of the bridge, for easier removal, Titebond may just be the way to go.

Have you heard of "Hide Glue: Historical and Practical Applications" by Stephen A. Shepherd? Great book...

..and one I just pulled out because apparently I didn't read through it thoroughly enough.

In the "Reversing Hide Glue" chapter, he goes over wet heat, dry heat, and alcohol. The (denatured or pure ethanol ) alcohol (isopropyl contains some water) allegedly crystallizes the glue and allows it to be taken apart.

One of the main selling points of hide glue is that it's easily reversible, and he doesn't contest that point. It just requires, apparently, some different methods. I haven't tried the alcohol thing before but some reading online alleges that violin makers use this method as well. Could be worth a shot.

Either way, makes me feel better about owning a brass glue pot and warmer from Music Caravan, an ultra duster hog hair brush by Marx, and some dry hide glue. I hadn't used it in a while and I'm glad to be excited about getting back into it.

[zhunter]

There are situations where I'll take the compromise solution. It is no big deal really. Especially if it works.

hunter

[DanPanther]

I haven't read every post, but most. If he shaves the top of the bridge, has anyone mentioned that he will also have to shave the bottom of the saddle. If not nothing will change.
Attempting to deepen the saddle slot on the bridge, is asking for trouble.

Dan

[Slight Return]

Originally Posted by DanPanther

I haven't read every post, but most. If he shaves the top of the bridge, has anyone mentioned that he will also have to shave the bottom of the saddle. If not nothing will change.

Dan

Yes, this was my main point. Remove the bridge, sand the bottom and re-glue it, and the action will be lowered directly. Sand the top of the bridge and you have to take the saddle down too, or nothing will change.

I'm not against compromises either if they work; it's just a matter of longevity. Even a neck reset is a compromise in the sense that it's not permanent. The top can still shift and change after a neck reset, requiring another neck reset in the future. This is one of the main reasons I've always seen bolt-on necks as superior from a design and repair perspective.

It might not be traditional, but in the long-run it makes everything much, much easier. A traditional neck reset is a very intimidating job, and certainly not for an amateur; however, for example with Taylor's bolt-on neck setup, a neck reset isn't much harder than doing a standard setup. A lot less headaches all around, including less stress knowing that if the top shifts again, another neck reset can be done easily and basically hassle-free.

[Stony32]

Originally Posted by Slight Return

Shaving the bottom of the bridge will not affect the break angle at all in any way. The break angle would remain exactly the same; you would simply have lower action.



Break angle is dictated by the distance between the string's contact point on the saddle and its contact point on the bridge, both in terms of the actual height of the bridge in relation to saddle height, and any ramping/slotting and bridge pin hole placement that affects the string's distance from the saddle.

Shaving the top of the bridge will increase the break angle by increasing the distance between the string's contact point on the top of the bridge and the contact point on the saddle. At the same time, however, you are making the saddle slot shallower, and will need to either file or rout the saddle slot deeper to keep the saddle from tipping.

And unless you cut a new, higher saddle, or shim the current saddle, you will end up with the same exact break angle as before, because deepening the saddle slot = lowering the saddle height. So effectively the ratio of bridge to saddle height would end up being exactly the same; you'd just have lower action. No change in break angle.

When you shave the bottom of the bridge and re-glue it, you can simply cut a new, higher saddle, or shim the current saddle, without having to touch the saddle slot at all.

And installing a new, higher saddle, or shimming the current saddle, will increase the break angle and downward tension on the top.

You're accomplishing the same thing in both scenarios. Just different ways to skin a cat. Shaving the bridge from the top will require that you modify the saddle slot accordingly, and either shim the current saddle or cut a new one.

Shaving the bridge from the bottom will require removing the bridge and re-gluing the bridge. The saddle height and break angle can be left completely unchanged, because you're not changing the saddle slot depth.

I could've done the same thing by sanding down the top of the bridge and deepening the saddle slot and cutting a new, taller saddle, but my preference was to simply remove the bridge, sand it from the bottom, and glue it back on.

I actually had to cut a new bone saddle for it because the original saddle, while the break angle was still the same, was now too low -- the strings were flat against the frets.

So now I have a nice, tall saddle with very good break angle and I didn't have to touch the saddle slot at all.

I also wanted to use hot hide glue for the bridge, to make any future changing of the bridge easier, as hide glue will come apart very easily with heat or a very small amount of steam.

I think of the break angle as being the angle caused by the string breaking over the saddle, where, in geometric terms, the line from nut to saddle intersects with the line from the saddle to the bridge. If you lower the bridge by shaving the bottom, you increase (widen) that angle because the geometry is changed in the line from the nut to the bridge. Theoretically, if the top of the saddle is close enough to the top of the bridge and the bridge is shaved enough from the bottom, the break angle I am referring to is 180 degrees (straight line from bridge to nut). So, as you can see, dealing only with the angle from bridge to saddle only gives you half of the story in terms of downward pressure on the saddle.