I was wondering if anyone could explain what the exact mechanism is that would cause a bridge to lift on a new or newer guitar.

I ask this because I recently noticed a slight lifting of the bridge on my 6 month old L-03R.  Not really bad but bad enough that it appears it will be covered under warranty (waiting for confirmation on this).  This guitar has been babied under my care as far as humidity and temperature are concerned.  

Incidentally, I was playing a few guitars at a local shop last night and played another L-03R (that I had actually played prior to buying mine but didn't really like the sound or playability that much) and noticed that the bridge was severely lifted on this one.  So I guess another question would be does anyone have any experience with how much and in what way a severely lifted bridge would affect tone.  Makes me glad I decided not to buy this one and held out for one that "spoke" to me.  As an aside, my guitar was purchased at a different store, same chain though.

BTW - I don't mean to imply any quality issues with these guitars, I love my L-03R and can't wait to get it back.  There's to many things that could happen to these guitars between leaving the factory and getting into my hands to make any connections to quality of construction.

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The store might not be humidifed properly.If they where tuned higher then stardard pitch for a long period of time.I know of a chain store that shine's 200 watt spotlights on there acoustic and the room is always 5-10 degrees hotter then the rest of the store.Where are you located?

The store I was at last night was in Saint John, New Brunswick, Canada.  Their room seemed pretty good to me.  If it was too hot , I should have noticed, I certainly spend enough time in there.  I also noticed that they had a humidifer in the room.  The lighting was fine too, not too bright.

Does the low humidity dry out the glue or does the bellying of the top tend to pull it away from the bridge?  I'm also guessing it it's too warm then that would tend to soften the glue.

The usual causes are poor joint preparation and bad glue. I think if neither of these conditions are present then the top should crack before the bridge comes loose in low humidity(because a good joint is stronger than the wood). The temp should have to reach well over 100f for the glue to soften.

Quote from: unclrob on January 20, 2011, 09:08:06 AM
The store might not be humidifed properly.If they where tuned higher then stardard pitch for a long period of time.I know of a chain store that shine's 200 watt spotlights on there acoustic and the room is always 5-10 degrees hotter then the rest of the store.Where are you located?

How long would you consider a long period of time? (on the being tuned higher than standard pitch)

Just being tuned to higher pitch should not in itself do it - but being under a spotlight for a while could easily soften the glue. Black bridge will absorb heat much more quickly than the spruce top, although the bridges mass will offset that gain, but those spotlights can easily generate enough heat to allow the glue joint to soften, and then the mechanical connection from the strings and bridge pin wedging is all that is holding the bridge in place.

Alot of possibilities - luckily it's easy to get fixed, and very rarely happens twice - 

Lifting Bridges - good name for a group.

Laminate Boy - A good name for a super hero.   :winkin:

Quote from: mlejeune67 on January 20, 2011, 09:32:37 AM
The store I was at last night was in Saint John, New Brunswick, Canada.  Their room seemed pretty good to me.  If it was too hot , I should have noticed, I certainly spend enough time in there.  I also noticed that they had a humidifer in the room.  The lighting was fine too, not too bright.

Does the low humidity dry out the glue or does the bellying of the top tend to pull it away from the bridge?  I'm also guessing it it's too warm then that would tend to soften the glue.

I doubt that dry conditions would contribute to a lifting bridge. But high RH would cause bulge in the top. Combine warm and humid and the possibilty of a bad glue job...

Next time you're there, have a look across the tops of the guitars. If the top is bellying or bulging, it's likely from high RH. Slight bulge is normal, excessive bellying is suspect.

I purchased an L-02 last summer - it was only in the store a day or two after coming straight from the Vancouver factory.  Five weeks after purchase the bridge started to lift.  The guitar had been babied and RH had never varied outside of 42-45%.  I thought about going the warranty route but decided to have it repaired locally - even though I only live a couple of hours drive from Vancouver.  Shipping/insurance would have cost about $100 and over the past several years I've had some absolutely horrible experiences with shipping companies - I seem to have a black cloud that follows me around when it comes to shipping anything.  I was hoping that the repairs could be done locally for about $100.

A local luthier did the repairs and confirmed that it was definitely poor joint preparation/poor gluing technique that caused the bridge to lift.  He had to do more work than anticipated (including building a new ebony bridge) - and it ended up costing $200.  I don't regret handling things this way - the guitar is as good (or better) than new.  For me it was worth it to not have to ship.   

That's an unfortunate story.  Did your luthier say why he had to replace the bridge? 

The new L-02 I've played was fantastic.  I pick it up everytime I'm in the store it's at.  I can't figure out why it's still there.

I really wasn't trying to stir any pots here.  I really hope that this sort of thing is isolated.  I guess we'll just see where the thread leads us.

T'aint nothing wrong with stirrin the pot.Let us know what you find out.

When wood is involved there are multiple reasons for lifting and joint failures.  I would suspect poor joint prep is the most common problem.  That said all major producers of guitars will have a few get away.  It is how they step up to the plate when faced with a problem that's important to me.

Quote from: mlejeune67 on January 22, 2011, 09:41:16 AM
That's an unfortunate story.  Did your luthier say why he had to replace the bridge? 

The new L-02 I've played was fantastic.  I pick it up everytime I'm in the store it's at.  I can't figure out why it's still there.

I really wasn't trying to stir any pots here.  I really hope that this sort of thing is isolated.  I guess we'll just see where the thread leads us.

When the bridge was removed there were problems with the way the soundboard had been prepared.  He had to sand that down and back fill (probably not the correct term but you get the idea) with a piece of maple.  In order for the repair to not show he then had to make a slightly oversized bridge.  Bottom line - the luthier did a great job - it looks and plays like brand new.  You cannot tell the bridge is not original.

FWIW the luthier said he suspected an apprentice did the original bridge attachment and got away with sloppy work.  I thought about contacting Larrivee and letting them know what happened, but I'm sure they'd dismiss it as someone who didn't take care of their guitar and was looking to get something out of the situation - and I didn't need the stress.  When I saw this thread I thought it would be a good idea to add my experience since the problem doesn't appear to be isolated.  Were the guitars you were looking at made in Vancouver?

Like you I also love the L-02.

In defense to Larrivee (or other builders) the case where a problem exists tends to get a ton of play on internet forums, not the thousands that have never had an issue.  I too would be disappointed if the same happened to me but stating what Larrivee would probably do without giving them a chance to address the issue seems a bit unfair to them.

The two guitars in question, one I own and one on the wall at a local guitar shop, were both made in Canada. 

I agree with the sentiment that these things can get blown out of proportion on the net.  I also want to reiterate that the original intent of this thread was to learn about how this happens especially on a new or newer guitar.  Somebody who's actually had that sort of problem and had it resolved is a great source of info.

The dealer has sent my guitar to their repair shop and have indicated to me that this is definitely a warranty issue.  They did question me about humidity but I assured them the guitar had been babied and they could also tell by looking at the guitar that it was humidified properly.  I should be hearing this week what the resolution will be. 

The shop where I noticed this immediately took the guitar off the wall and were already working on getting it fixed as I was leaving the store.

 :thumb.Sounds like a great store to do business with.

I'd be curious to hear what was involved in the of repair of you L-03.  When it happened to me I was hoping that it was just a matter of removing the bridge and gluing it back on - but it turned out to be not that straightforward.

Quote from: SMan on January 22, 2011, 11:03:40 AM
In defense to Larrivee (or other builders) the case where a problem exists tends to get a ton of play on internet forums, not the thousands that have never had an issue.  I too would be disappointed if the same happened to me but stating what Larrivee would probably do without giving them a chance to address the issue seems a bit unfair to them.

Just to be clear I was talking about letting Larrivee know about the problem after it was fixed - mostly as a courtesy to let them know what had happened.  And yes - even under those circumstances - it was probably a bit unfair to prejudge how they would respond to such info.  I'm sure that the guitar would have been repaired under warranty had I shipped it to them - but as I said earlier shipping really never was an option. 

Quote from: kap55 on January 23, 2011, 07:49:43 AM
I'd be curious to hear what was involved in the of repair of you L-03.  When it happened to me I was hoping that it was just a matter of removing the bridge and gluing it back on - but it turned out to be not that straightforward.

Usually, that's all it should be. The trick is to get the bridge off cleanly, and if the problem is glue joint failure, then they should come off pretty cleanly. If the top has gotten damaged, that would indicate (to me) that the glue joint was decent, and there may have been another problem, or that there was a problem getting the bridge off. 

Quote from: tadol on January 23, 2011, 06:47:02 PM
Usually, that's all it should be. The trick is to get the bridge off cleanly, and if the problem is glue joint failure, then they should come off pretty cleanly. If the top has gotten damaged, that would indicate (to me) that the glue joint was decent, and there may have been another problem, or that there was a problem getting the bridge off.  

Wouldn't they just heat the bridge to soften the glue and then just peel it up with a thin putty knife?

I can stick a piece of printer paper under the bridge on my F-III in a few places, it's been like that since I got it and hasn't gotten any worse so I just figured it was no big deal. Maybe I was wrong.

Yes you can heat it of.I've been using the old style method of  popping the bridge off forever and never had a problem.

Most companies leave about a 32" area of the bridge bottom clear of glue.I have seen bridge's that just have a swirl of glue and some that cover the whole bottom with glue.I've seen guitars  that had the bridge mounted to the finish that just had some scratche's into the finish.

Quote from: unclrob on January 23, 2011, 10:30:43 PM
Yes you can heat it of.I've been using the old style method of  popping the bridge off forever and never had a problem.

Most companies leave about a 32" area of the bridge bottom clear of glue.I have seen bridge's that just have a swirl of glue and some that cover the whole bottom with glue.I've seen guitars  that had the bridge mounted to the finish that just had some scratche's into the finish.

So does that mean I shouldn't worry about my bridge?  I could send you a couple pics.

Unless its lifting I wouldn't worry about it.Larrivee leaves about a 32' not glued.That little bit sits over the finished top.If it does lift get to your favorite tech/luthier and have it popped and reglued.

One thing I need to add,as a tech I have to know how everyone builds there stuff so I know how to fix it.Also I no longer do neck sets mostly because everyone thinks its so easy because they saw how its done on the internet and it looks easy.

Mine was not that bad but I could get a piece paper about 1/8" under the bridge all the way across the back.  It didn't seem to me that this was there when I bought the guitar (I didn't really check though) and also the guitar is brand new and under warranty, so I thought I would at least get it checked out.  My dealer seemed to think that this was an issue and should be resolved now rather than later.  This sort of thing also would have kept eating away at me so I was glad to get it checked by the dealer and glad it's being resolved now.  Would it have stayed the way it is?  Hard to say. 

I checked my other two acoustics and one had absolutely no lifting at all and the other had slight lifting on the wing of the bridge but this guitar is about thirteen years old and has not always been babied so I'm not necessarily surprised or shocked at that.

Here's some coffee and donuts for all those chiming in on this one;   :coffee :coffee :coffee :coffee :donut2 :donut2 :donut2 :donut2 :donut :donut :donut :donut

It would not alarm me if I could slip a piece of paper slightly under the corner of a bridge.  (Keeping in mind that many acoustic guitar tops have a radius and are not flat .)  Lifting and being able to slip a piece of paper barely under an edge may be two different issues.

Quote from: tadol on January 23, 2011, 06:47:02 PM
Usually, that's all it should be. The trick is to get the bridge off cleanly, and if the problem is glue joint failure, then they should come off pretty cleanly. If the top has gotten damaged, that would indicate (to me) that the glue joint was decent, and there may have been another problem, or that there was a problem getting the bridge off. 

What I was told by the fellow that repaired mine was that, during manufacture, once the surface of the guitar is finished a router is used to "rough up" the area where the bridge will be attached.  On my guitar this was uneven/irregular which is why he had to use a piece of maple to backfill prior to gluing the new bridge on. 

Quote from: kap55 on January 24, 2011, 09:04:25 AM
What I was told by the fellow that repaired mine was that, during manufacture, once the surface of the guitar is finished a router is used to "rough up" the area where the bridge will be attached.  On my guitar this was uneven/irregular which is why he had to use a piece of maple to backfill prior to gluing the new bridge on. 

If they had to backfill why wouldn't they use Spruce, thats what the top is made of?

Quote from: Mr_LV19E on January 24, 2011, 09:19:45 AM
If they had to backfill why wouldn't they use Spruce, thats what the top is made of?

I'm not sure - I never thought to ask.  At the time I just figured the piece would be very thin and since maple is harder that it may have been more stable or easier to work with, but that's only my theory.

If I'm not mistakenand I could be very wrong when I've removed bridge's from larrivee's the area were the bridge is being glue is taped off before the finish is apllied then after the finish is sprayed on then the bridge is glued into place.I don't believe that they route off the finish.

Quote from: unclrob on January 24, 2011, 12:05:07 PM
If I'm not mistakenand I could be very wrong when I've removed bridge's from larrivee's the area were the bridge is being glue is taped off before the finish is apllied then after the finish is sprayed on then the bridge is glued into place.I don't believe that they route off the finish.

They do or did at least. It's quicker to route it off.

http://www.youtube.com/watch?v=wcJVh-kOXhg

I rather not see them route off the finish to many chance's of damaging the guitar.I have seen some companies that will install the bridge then tape it off then spray on the finish.

The video certainly tells a lot of the story.  Thanks!  Too bad it doesn't show the bridge going on.  From the video it would seem then that a critical part of this is getting all the finish off.  Perhaps it's harder to get it all off around the edges and the glue won't stick well to any leftover finish?

I've started to watch those videos but didn't make it all the way through.  Fascinating stuff though.

Quote from: mlejeune67 on January 24, 2011, 03:49:38 PM
The video certainly tells a lot of the story.  Thanks!  Too bad it doesn't show the bridge going on.  From the video it would seem then that a critical part of this is getting all the finish off.  Perhaps it's harder to get it all off around the edges and the glue won't stick well to any leftover finish?

That's true but decreasing the the wood to wood surface a tiny amount won't matter. It'd be the same as decreasing the footprint of the bridge an insignificant amount. Now if the left over finish(which is a raised surface comparatively) keeps the bridge elevated then that could cause a problem.

Quote from: unclrob on January 24, 2011, 02:50:38 PM
I rather not see them route off the finish to many chance's of damaging the guitar.I have seen some companies that will install the bridge then tape it off then spray on the finish.

Yeah but that's much more difficult or at least time consuming. For anyone who hasn't done this... It requires a patch of tape cut very precisely. Then you basically have to locate the bridge position twice which is kinda like in archery hitting the bullseye then splitting the first arrow with the second shot(ok, not quite that difficult but you get the idea). After the finish is applied then you have to precisely cut out the tape with a razor without cutting into the wood.

Temp plated and a CAC might work but still..I saw a program which showed how Taylor use's a lazar cutter to cut the tops to shape I wonder if the technology has gotten to a point that a lazar could be use to remove the finish in the bridge area but having refinish a lot of guitars the finish gets deep into the wood.

Quote from: unclrob on January 24, 2011, 08:43:33 PM
Temp plated and a CAC might work but still..I saw a program which showed how Taylor use's a lazar cutter to cut the tops to shape I wonder if the technology has gotten to a point that a lazar could be use to remove the finish in the bridge area but having refinish a lot of guitars the finish gets deep into the wood.

Actually, that sounds like a good idea. Maybe a template(like taping it off) to act as a backstop if the laser couldn't differentiate between finish and wood.

I have a 94 OM-10 with a lifted bridge. Last summer, I moved it to a closet that was on the opposite side of the bathroom wall - in other words, more humid than I realized. The weather here gets very humid in the summer anyway, though we use AC and a dehumidifier to keep it under control.

It isn't lifted very far. I only spotted it because I was holding it up to a light to admire the 3D effect of that incredible silking. I had just finished a very enjoyable practice session, and the tone was not suffering at all. However, a sheet of paper will slide pretty far under the center section of the bridge. It's currently sitting with loosened strings, waiting for better shipping weather.

Had a bit of spare time this AM and thought I would try posting some pics to see if I could get it to work now that I have enough posts.  These are of the bridge of my L-03R prior to bringing it back to the dealer.

[attachment deleted by admin]

That looks like about the right amount of depth that would be were the bridge sits over the finish area under the bridge.I know this may be a dumb question but can you see it lifting or is it just that you can slide a piece of paper under it?This is not meant to offend just trying to understand better.Can you take a pix of the back of the bridge were it sits on the body.I'm just trying to get a better grip on whats going on.

Here's some pic's of mine.  I haven't been real worried about it, just figured I'd send the photos to Jim once he's feeling better and let him decide what if anything should be done.

(http://i199.photobucket.com/albums/aa242/daddyo12453/LS-03HB/IMG_2139_1_1.jpg)
(http://i199.photobucket.com/albums/aa242/daddyo12453/LS-03HB/IMG_2150_10_1.jpg)
(http://i199.photobucket.com/albums/aa242/daddyo12453/LS-03HB/IMG_2152_12_1.jpg)

unclrob, no offense taken. 

I did notice a slight lifting with my naked eye before trying it with paper.  The lifting doesn't really show in the pics I took.  It is a thin sheet of paper, I don't think a thick business card would fit under far if at all.  Even if there's no glue there shouldn't it still be tight to the soundboard?  I wasn't sure what to think which is why I brought it to my dealer.  Was tempted to post here first but figured they would the final judge of whether it was an issue.  They seemed to feel it was an issue and I was happy to get it resolved now rather than later.  Of course I'm working under the assumption that it would worse.

Theres about a post-its of finish above the cleared area for gluing the bridge.That said if you can see the lift I'd say get it popped and reglued.I glue it all down by which I mean I look for squeeze out of glue.

I'm glad no offence was takin

LV thanks for the pix.

I just received my L-03R back from the dealer after having the bridge reglued under warranty.  As the OP I thought you might appreciate an update.

The repair looks really good and I can't find fault with it at all.  I spoke with the tech who worked on it and he couldn't find a problem with the join.  He indicated that it was caused by humidity.  I'm really confident that this guitar was properly humidified so this would have had to happen before I purchased.  This brings me back to my original question a bit.  How does this cause the bridge to lift if it's installed properly?

I also feel compelled to mention how well the dealer handled this.  They are part of national chain here in Canada and I'm usually not big on chains.  They are pretty much the only place locally where there's a good selection of Larrivees though.  They took this in on warranty without any hassle, gave me a very nice guitar from their rental fleet, shipped the guitar to a qualified tech at another one of their dealers, and had it back to me within a month.  They also adjusted the setup and filed the fret ends.  I think the tech even said he put on new strings.  All at no cost to me.  A happy ending.

Quote from: mlejeune67 on February 19, 2011, 07:35:10 AM
IThe repair looks really good and I can't find fault with it at all.  I spoke with the tech who worked on it and he couldn't find a problem with the join.  He indicated that it was caused by humidity.  I'm really confident that this guitar was properly humidified so this would have had to happen before I purchased.  This brings me back to my original question a bit.  How does this cause the bridge to lift if it's installed properly?

Woods gain and loose moisture according to the RH in the surrounding environment and glue does not. When woods take on moisture they swell and when woods lose moisture they shrink. Since the glue really doesn't appreciably gain or loose moisture, once cured, something has to give and that someting is the wood.

Plus the one rule of woodworking that is by necessity broken in guitar building is that you never glue wood to itself at right angles. Wood expands considerably across the grain, but not at all along the grain. When building furniture, alot of effort is put into making any connections at right angles capable of floating. Look under any solid wood table top, for instance.

As long as a cross grain glue joint is kept at a constant relative humidity, it will be fine. But any changes that cause the top or the bridge to move - however slightly - will affect the glue bond. Add the tension or uplift pressure from the strings, and the back of the bridge will be the first place you'll see it. That's the main reason the complete removal of the finish from under the bridge, and the shaping of the bridge to match the contour of the top, are so important. You really want to get the maximum glue area and most effective bond possible - but you also want to be able to take it apart and re-do it relatively easily if you need to.

The fact that so many guitars get subjected to so much and are still holding together after many years of use is testimony to the skill of their builders, and the quality of their materials - but the need to reglue bridges ( or re-set necks ) is certainly not a knock on them, or the sign of a bad or problem instrument - 

Your re-glued bridge is probably stronger than a new guitars - I doubt you'll have any other problem with it.

Thanks!  I think I understand better whats going on there now.  Really appreciate all the comments. 

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