Advice on bellied up top

[petscar]

I saw on you tube where someone put a damp towel inside a guitar with a bellied up top by the bridge on a plastic margarine tub top, then covered the sound hole with another tub top and claimed the belly relaxed & went down a bit. I tried it for a couple of days with no result. So I decided to try again with a weight on the top by the bridge this time. Anyone see a problem with this??

I don't want to try a bridge truss just yet. After it settles, you are supposed to wait a week before restringing. It's not too bad to begin with but it is a 30 year old Yamaha laminate that I want to try to get the best action out of.

Also, I will be sanding down the bridge & saddle as well as adjusting the truss rod. My question is, is there a maximum I should sand down the saddle? I heard if it is too low coming out of the bridge, the angle of the string coming out of the end pin hole can adversely affect tone & volume. How do you know how much saddle height to leave before it affects tone & volume? Is less of an angle coming out of the end pin hole the thing that causes this issue. By sanding the bridge down, does this compensate for the sanding of the saddle as far as string angle and where do you stop?

[eugenro2001]

I had the same problem. Take a look at this:
http://fretsnet.ning.com/forum/topic...a-with-bellied

Is more than a year and the guitar is just fine.

[Misty44]

How much belly do you have?

Lay a straightedge (long enough to extend over the edges) across the belly just below the bridge and hold it still (doesn't have to be level). Now measure the clearance from both edges up to the bottom of the straightedge. If the combined total is 1/2" of less you're fine, that's normal. A little more than that may still not be a problem.

What do you measure?

I tried it for a couple of days with no result.

If it is indeed a matter of humidifying the wood, a couple of days may not be enough time - more like a week of two would be in order if that's the problem. If not, you'll over-humidify, which can cause separate problems.

[Howard Klepper]

Originally Posted by petscar

I saw on you tube where someone put a damp towel inside a guitar with a bellied up top by the bridge on a plastic margarine tub top, then covered the sound hole with another tub top and claimed the belly relaxed & went down a bit. I tried it for a couple of days with no result. So I decided to try again with a weight on the top by the bridge this time. Anyone see a problem with this??

Don't do that. Get that wet towel out of your guitar before you start growing mold and disassembling glue joints. Guitars do not belly up because they are dry. Don't look for amateur repair advice on You Tube. Some people have gotten the wrongheaded idea that every guitar problem means that it needs to be humidified.

It always helps to identify what guitar you are talking about.

[petscar]

Thanks for the info. I removed the towel and as I didn't measure the belly before, I can't be sure if it helped. How difficult/easy is it to install a bridge truss. This has become a hobby for me so I'd like to try it myself. The guitars I am looking at doing it to are all Yamaha FG laminates - 335II, 336SB & 340.

[Misty44]

I don't think anyone can help you unless you provide measurements, and photos would help too.

How do you know you have a belly problem? What do you get when you measure the gap on the edges as described earlier?

I will be sanding down the bridge & saddle

Sanding the bridge is a stop-gap measure at best before a neck reset. If you want to lower the action at the 12th fret, then lower the saddle, forget the bridge.

What is the current action at the 12th fret?

This has become a hobby for me so I'd like to try it myself.

Doing your own set-up's and modifications is a great way to learn, BUT you have to know what you're doing, and so far it doesn't sound like you do.

If I'm wrong, please excuse me.

Can you provide the two measurements? Perhaps the experts here can help you from there or guide you to on-line resources such as FRETS.com.

[petscar]

It's not so much a belly problem. It is an action issue and the higher belly adds to it. So I was trying to take a little improvement from every possible area. The height on the edge of the guitar is barely 5/16". The action at the 12th fret was 1/4" but is now down to under 5/16" from truss rod adjust & sanding the saddle to which I have a little more room to sand.

The reason I mentioned sanding the bridge is because another guitar (which I bought that way) had great action height (actually a tad too low) but the saddle was sanded so low that is it barely higher than the bridge ( I will be replacing the saddle with bone). Thus the tone from the strings is kind of dead. Thus my original question was: "My question is, is there a maximum I should sand down the saddle? I heard if it is too low coming out of the bridge, the angle of the string coming out of the end pin hole can adversely affect tone & volume. How do you know how much saddle height to leave before it affects tone & volume? Is less of an angle coming out of the end pin hole the thing that causes this issue. By sanding the bridge down, does this compensate for the sanding of the saddle as far as string angle and where do you stop?"

While I am in a learning process I have done some research. That is why I am here, to pick your brains. I have done several basic adjustments like saddle, truss rod & nut but am looking to go a little beyond at this point. I am considering trying a bridge truss system as I understand they work very well with these particular Yamahas. There are some that don't like them, but that is why I am considering tryinf it on the worst of my Yamaha's first so I can see for myself. Worst case scenario, the guitar cost me $125 But the education will be priceless. Any further info will be greatly appreciated.

PS. These guitars are not worth a neck reset. I just want to get the most out of what I have to work with.

[donh]

www.frets.com

read the whole site, then ask

[charles Tauber]

Originally Posted by petscar

It's not so much a belly problem...I am considering trying a bridge truss system

Either it's a belly problem or not. If not, the truss system is a potential solution for a problem you don't have. Fix the problems you have, not the ones you don't have.

While I am in a learning process I have done some research. That is why I am here, to pick your brains.

There is a lot of quackery out there, as the Youtube video to which you refer demonstrates. If you are going to teach yourself, at least look to reputable sources of information. And apply common sense to what you are learning.

[Neil K Walk]

Yup. You got some bad advice putting a damp towel in direct contact with the unfinished wood inside the guitar's body. A belly isn't from a guitar being underhumidified; it's most likely from heat stress. The glue probably softened up enough to weaken it and most likely the bracing underneath the bridge wing has pulled away with help of the string tension. Get yourself a dental mirror and a small flashlight and check for gaps. Another thing you should look for is any gaps between the bridge and the soundboard because that's also prone to failing due to heat stress.

[petscar]

read the whole site, then ask

Thanks I will. That is one BIG site. Lots to read.

Either it's a belly problem or not. If not, the truss system is a potential solution for a problem you don't have. Fix the problems you have, not the ones you don't have.

Actually if you know about the bridge truss system, you would know it is more than just fixing a bellied top. That is just one benefit. Even guitars without a belly problem benefit from this system as it increases volume and improves tone. While some have tried it and said it didn't do anything, others have had great success. You Tube has a before/after comparison on a Yamaha FG335. Here is a link from a luthier who has done this hundreds of times. Incidentally the older Yamaha FG's seem to respond consistently well to this system.

http://www.epinions.com/review/Yamah...t_479134060164

There is a lot of quackery out there, as the Youtube video to which you refer demonstrates. If you are going to teach yourself, at least look to reputable sources of information. And apply common sense to what you are learning.


I agree, that is why I am asking here. FYI there are those who have tried this with success. Common sense tells me if I can reduce the belly even just a tad, it will certainly help with the action and that much less I would have to reduce the saddle/bridge. Is it wise to try to reduce the belly in this fashion?....again, that is why I am here asking these questions.

Yup. You got some bad advice putting a damp towel in direct contact with the unfinished wood inside the guitar's body. A belly isn't from a guitar being underhumidified; it's most likely from heat stress.

Actually, I said the towel was placed on a plastic margarine cover inside the soundhole and not on the wood directly. I think the point is not that the belly occured from being underhumidified, but that the humidity would reduce some rigidity so the top could flex a little to reduce the belly.

The glue probably softened up enough to weaken it and most likely the bracing underneath the bridge wing has pulled away with help of the string tension.

The bracing is fine. The amount of bellying is minimal and just a natural result of 30 years of string tension. As I said before, I am trying to take a little help from every possible area to get these guitars as playable as possible without having a neck reset as they are inexpensive guitars and would not be worth spending that amount of money seeing you can buy these for less than $200.

For the 3rd time I will ask again:

"My question is, is there a maximum I should sand down the saddle? I heard if it is too low coming out of the bridge, the angle of the string coming out of the end pin hole can adversely affect tone & volume. How do you know how much saddle height to leave before it affects tone & volume? Is less of an angle coming out of the end pin hole the thing that causes this issue. By sanding the bridge down, does this compensate for the sanding of the saddle as far as string angle and where do you stop?"



Maybe someone can answer this in the meantime while I read the website I was provided.

Thanks

[runamuck]

Originally Posted by petscar

For the 3rd time I will ask again:

[B]"My question is, is there a maximum I should sand down the saddle? I heard if it is too low coming out of the bridge, the angle of the string coming out of the end pin hole can adversely affect tone & volume. How do you know how much saddle height to leave before it affects tone & volume? Is less of an angle coming out of the end pin hole the thing that causes this issue. By sanding the bridge down, does this compensate for the sanding of the saddle as far as string angle and where do you stop?"

Maybe someone can answer this in the meantime while I read the website I was provided. Thanks

Regarding how much is too much reduction in saddle height - it depends, and
there are no hard and fast rules about this. I suggest that you make some measurements to determine how much saddle height needs to be reduced
to get the action where you want it.

It may be that no matter how much you take off the saddle you wont be able to lower the action enough and all that's left is a neck reset. But I've seen and heard a few guitars that sounded OK with not much left of the saddle. But the general idea is that more volume and power will be reduced the lower you go.

The approach can be different for different instruments and different players. If you just want to be able to comfortably play the **** thing and it's not an expensive instrument - well I wouldn't sweat it. If on the other hand we're talking about an expensive instrument, well...

There are two issues affected here: the break angle from the pin holes up to the saddle as well as down bearing pressure from the strings to the top via
the saddle and bridge. Changing any of that may cause changes in volume.

Lowering the bridge height makes it possible to lower the saddle more than you could otherwise but when you change the mass of the bridge you can
affect your guitar's tonality - especially bass to treble relationships. I've done it on a couple inexpensive guitars and couldn't really hear the difference. On the other hand, I wouldn't dream of doing that to a very responsive guitar because there would certainly be a difference that would be difficult to predict.

There are a lot of variables going on here so it's very difficult to say anything
specifically without playing your particular guitar.

I haven't read this entire thread and maybe you've said what kind of guitar you have. If it is inexpensive then it probably has a laminated top. If that's true I really don't think you'll harm the questionable acoustic qualities of it anyway. I'd say to just go slowly and experiment.

The biggest concern it that you get the saddle properly intonated if you start
carving away at it.

Jim McCarthy

[Misty44]

My question is, is there a maximum I should sand down the saddle? I heard if it is too low coming out of the bridge, the angle of the string coming out of the end pin hole can adversely affect tone & volume.

Okay, here's one ideal set of measurements that we'll refer to only as a baseline that may help us figure this out:

Action at 12th fret: 3/32" (space btw the top of the fret and bottom of the low E string)

Saddle height at the bridge: 1/2" (from the top of guitar to bottom of low E)

Saddle height sticking out of the bridge: 3/32"

Neck Relief: 0.004"- 0.010"

Break Angle i.e "string angle" from hole to top of saddle: 40-50 degrees + or -.

You said earlier that "The action at the 12th fret was 1/4" but is now down to under 5/16" from truss rod adjust & sanding the saddle to which I have a little more room to sand," which is a little confusing since 5/16 is greater than 1/4, which is 8/32 which is more than twice the height of the "baseline" we established above (which of course can vary by a bit to accommodate playing style). And even with that height you apparently only have "a little" more saddle to sand?

Again, without exact measurements (and photos would really help), we're all just guessing here.

So what you're saying is that you have extremely high action and minimum saddle to lower? And now you're concerned that if you lower the saddle even more that you will minimize the "break angle" to the point where it diminishes volume and punch?

Is that the situation?

That is one BIG site.

Sure is. Frank Ford has done an outstanding job of creating an online encyclopedia of guitar care and repair that would taking anyone days to peruse.

So you need to focus.

I would start here with your ruler in hand: http://www.frets.com/FRETSPages/Musi...neckangle.html



I would also read Bryan Kimsey's piece on Ramping (which affects the "break angle"): www.bryankimsey.com/bridges/slotted.htm It appearts after the section on "Slotting."



From what you stated, it sounds like you need a "neck reset" to get the "neck angle" back in line. But until you provide some key data against the baseline figures, it's just guessing, a very dangerous practice!

But I admire you desire to learn and try your own set up and modifications. Keep at it.

So to answer your question, it's not just about the saddle. Perhaps Ramping the bridge would be a benefit, perhaps - gulp - a neck reset...but when you start to run out of saddle, then bigger issues other than sanding and ramping are at stake.

[petscar]

The website frets.com is excellent. A lot of valuable info. I had previously read on how to check the neck angle and while these 30 year old guitars don't have great neck angles, there is enough to work with without a reset.

So what you're saying is that you have extremely high action and minimum saddle to lower? And now you're concerned that if you lower the saddle even more that you will minimize the "break angle" to the point where it diminishes volume and punch?

Is that the situation?


Yes & no. The guitar with no saddle left to adjust is actually too low (the action) to begin with. The minimizing of the break angle part of my question is just general info I want to understand although that seems to be part of the issue with this low saddle which I will correct as explained below.

which is a little confusing since 5/16 is greater than 1/4,

Yea, I got that one wrong...I meant 5/32", not 5/16". It is quite playable but still a tad high but I have enough room on the Tusq saddle I installed to go down at least another 1/32" and maybe a tad more. On this particular guitar (FG340) I know I can get it where I want it without sanding the bridge.

On the FG335II, the saddle is barely above the bridge and the tone is somewhat deadened which I am guessing is because of such a low saddle and the break angle. The action on this is too low (about 5/64") so I planned to replace the saddle with bone and bring up the saddle height a tad. Hopefully this will restore the tone. The previous owner already ramped the bridge on this one (which I discovered as an option when I went to frets.com).

This is the guitar I am going to try the bridge truss on. If it takes a little of the belly out, it will only put me in a better position as far as action height & more flexibility to adjust for the future. However the main reason I want to try it is for better tone & volume. On the YouTube before/after comparison I could hear the difference. The luthier from whom I posted his link above swears by the bridge truss system for these Yamaha guitars. It is a $22 part and seems simple to install. If it works, I will install it on the FG340 and the FG336SB I just got which I haven't looked at closely yet, but it seems on first glance to be workable with all the solutions available to me.

I appreciate all your advice. I am open to any other suggestions as well and appreciate the links you guys have provided. Once I get around to installing the bridge truss I'll report back. I also got a couple of PM's from members who have installed the bridge truss with excellent results. I am looking forward to trying this. Thanks again.