Really bad belly bulge and dip in front of bridge - Ibanez j200 copy

[shaeryga]

Hello gearheads!
I’m new to this forum but am hoping to get to know it and find a place to meet peers and get advice : ).
I just got (a couple days ago) and early 70s Ibanez Jamboree 698.

I need to post photos for you all, the bulge behind the bridge and the dip in front of the bridge are the worst I’ve seen. Clearly a previous owner (from at-least 15+ years ago according to history from the seller) saw that the bridge was starting to come up from the top. Instead of taking the bridge off and fixing the problem, he used some unknown type of red/brown glue and simply glued it under the back where it was lifting.

The result is that instead of the bridge coming off, the entire top has been tugged into a bad bulge and dip from the previous owner leaving under tension and using it with the crappy repair.

There is a large x brace under the top, the front ends of each brace on each side have both been cracked open, not just from the belly but moreso it seems from dip behind the sound hole. When pressure is applied, the top braces return to place and the dip comes up.

I am hoping by taking the bridge off, allowing the wood to heat and humidify, relax and maybe clamp it somehow, that the top will return to relatively flat, especially after I’ve glued the braces that are broken (not reglued to the top but rather to themselves, as they’ve broken in half basically.

Any advice or thoughts for clamping, gluing, heating, removing the old bridge (who knows what kinda glue it is) and just all of it I appreciate the insight from anyone who has dealt with a situation like this.

Figured out photo posting!

https://i.imgur.com/M1iXXl7.jpeg

https://i.imgur.com/hv7FN3U.jpeg

https://i.imgur.com/wV0tHpC.jpeg

https://i.imgur.com/3Tvpdsc.jpeg

https://i.imgur.com/DSicS49.jpeg

https://i.imgur.com/Gq0EE3T.jpeg

[phavriluk]

OP: You're attempting serious repairs without, it seems to me, much of an idea of how these might be done and in what order. I suggest that OP finds a repair tech who (after being offered payment for their time) can diagnose what needs doing and in what order, if, in fact, this guitar is worth the expense of the repairs in the first place.

[shaeryga]

Originally Posted by phavriluk

OP: You're attempting serious repairs without, it seems to me, much of an idea of how these might be done and in what order. I suggest that OP finds a repair tech who (after being offered payment for their time) can diagnose what needs doing and in what order, if, in fact, this guitar is worth the expense of the repairs in the first place.

I appreciate the reply and I apologize for the lack of context. This is my first time posting here and I really didn’t want it to be multiple pages long. I have worked with guitars and wood all my life, I restore old upright pianos, build decks and furniture, I do a lot of wiring work on electrics for people and in general I am comfortable with tools and instrument repair.

I have not dealt with a top like this before, but I have worked with heat and hide glue, raw and laquered wood;

I am set on doing this repair myself, I’m excited to do it and learn, and I also am aware that I am missing certain specialty tools such as bridge clamps and I’m happy to put some money into tools.

My planned process so far:
I intend to heat and remove the bridge, I have already made a heat shield around the bridge shape to keep from overheating the laquer.

Once the bridge is removed I think I will see at least some improvement in the bulge, as I can tell the bridge itself is causing some stress from the way it was glued. The crappy repair done with glue that was too strong has definitely torn into the top at this point, I hope to save as much wood as possible by going as it gently from the front where the original hide glue remains.

So long as the pickguard isnt also stressing the top too much, I should be able to glue the braces once the bridge is removed

This part of my process is a WIP waiting on advice and I’ve been reaching out to luthiers and internet forums.

Perhaps I will put a clamp roughly the size of the bridge plate on and under the top, clamping it while humidifying and heating to encourage it to flatten out with help from the clamped and glued braces.

Perhaps I will replace/upgrade the bridge plate. But I am having a hard time finding online what type of thickness a j200 bridge plate should be, I’m sure they vary through the years.

I do not like bridge doctor type fixes. I want the top free floating, only connected to the sides, no internal post or anything.

Thanks!

[runamuck]

If the braces are broken across the grain they need to be replaced.

[shaeryga]

Originally Posted by runamuck

If the braces are broken across the grain they need to be replaced.

Good to know! Luckily they are broken pretty uniformly with the grain, not across.

[misterg]

Originally Posted by shaeryga

I cannot figure out how to post photos, the app says “the forum has disabled image sharing from this app”. Help with that would be appreciated

Have a look here:

https://www.acousticguitarforum.com/...d.php?t=231872

[nickv6]

Would it be worth considering fitting a bridge doctor first, filling the guitar with steam then let it all settle before removing the bridge doctor and fixing the bridge etc.
I say this because I fitted a bridge doctor to a guitar I was fond of. After about a year I decided to remove it and was amazed to find the top didn't immediately bow again at all, it had reset itself. And the fitting of the BD makes it easy to get the shape exactly as you want it.

[phavriluk]

A lot of comment on the bridge. I think the brace repair is first priority. And I'm repeating my comment that it will be to OP's advantage to get this problem child into the hands of a repair expert for an inspection before doing anything else.

[ChrisN]

https://proluthiertools.com/product/belly-reducer/
No experience, but I'd look at one of these.

[shaeryga]

Originally Posted by phavriluk

A lot of comment on the bridge. I think the brace repair is first priority. And I'm repeating my comment that it will be to OP's advantage to get this problem child into the hands of a repair expert for an inspection before doing anything else.

The opinion of an expert would be awesome, but unfortunately there literally aren’t any where I live. There are lots of hacks who I’ve brought guitars too only to get them back unfixed. There is one guy that does acoustic repairs in a town nearby, but he does not fix things, he replaced things. I’ve seen him rip some beautiful tops off of vintage gibsons and replace them entirely. I prefer keeping the old wood alive as much as possible, not just throwing it out.

In any case, I promise you there is not a luthier in my town that would have any idea what to do with something like this. So I’m resorting to advice and support from forums like this!

I’m certain I’ll figure it out : )

[shaeryga]

Originally Posted by ChrisN

https://proluthiertools.com/product/belly-reducer/

No experience, but I'd look at one of these.

Yes those look great! I’m currently stencilling out to maybe cast one of my own, I’m gonna have to make a custom one since they do not sell one for the j200 mustache bridge

[shaeryga]

Originally Posted by nickv6

Would it be worth considering fitting a bridge doctor first, filling the guitar with steam then let it all settle before removing the bridge doctor and fixing the bridge etc.
I say this because I fitted a bridge doctor to a guitar I was fond of. After about a year I decided to remove it and was amazed to find the top didn't immediately bow again at all, it had reset itself. And the fitting of the BD makes it easy to get the shape exactly as you want it.

I think that’s a great idea!

My bridge has one of those adjustable saddles that everybody hates, lucky for me that means extra holes through the top so I can mount a homebrew bridgedoctor type device without having to drill more holes in the top!

[shaeryga]

Originally Posted by shaeryga

Hello gearheads!
I’m new to this forum but am hoping to get to know it and find a place to meet peers and get advice : ).
I just got (a couple days ago) and early 70s Ibanez Jamboree 698.

Forum Help!
I cannot figure out how to post photos, the app says “the forum has disabled image sharing from this app”. Help with that would be appreciated

I need to post photos for you all, the bulge behind the bridge and the dip in front of the bridge are the worst I’ve seen. Clearly a previous owner (from at-least 15+ years ago according to history from the seller) saw that the bridge was starting to come up from the top. Instead of taking the bridge off and fixing the problem, he used some unknown type of red/brown glue and simply glued it under the back where it was lifting.

The result is that instead of the bridge coming off, the entire top has been tugged into a bad bulge and dip from the previous owner leaving under tension and using it with the crappy repair.

There is a large x brace under the top, the front ends of each brace on each side have both been cracked open, not just from the belly but moreso it seems from dip behind the sound hole. When pressure is applied, the top braces return to place and the dip comes up.

I am hoping by taking the bridge off, allowing the wood to heat and humidify, relax and maybe clamp it somehow, that the top will return to relatively flat, especially after I’ve glued the braces that are broken (not reglued to the top but rather to themselves, as they’ve broken in half basically.

Any advice or thoughts for clamping, gluing, heating, removing the old bridge (who knows what kinda glue it is) and just all of it I appreciate the insight from anyone who has dealt with a situation like this.

Will post photos once I know how!
Thanks : )

https://imgur.com/gallery/xs8ZzW8

[ChrisN]

Originally Posted by shaeryga

Yes those look great! I’m currently stencilling out to maybe cast one of my own, I’m gonna have to make a custom one since they do not sell one for the j200 mustache bridge

Another thing I'd relay is that my '70s Japanese student Conn OM, very lightly built, had a bad belly bulge that rotated the bridge. As it's not a valuable guitar, I tried the Bridge Doctor, and it gradually straightened everything out over a couple of weeks (safe humidity, and you keep tightening it up as the top moves). I then adjusted the Bridge Doctor for the best tone (least impact to the bridge while still applying slight counter-force to the bridge from below). None of my guitar's braces were detached/loose.

That was 2016 - belly's still flat, action hasn't budged (I reset the neck, too), and I think it sounds great.

Others' experience is to the contrary, so do your homework!

[JLS]

You figured out the way to get the best sound from that install! When I do an install, I'll tune the guitar up, and arbitrarily use the A string. I'll slowly tighten the JLD, which I left deliberately loose, and watch my strobetuner. When the strobe just begins to go sharp,I know the top is in equilibrium.

Oh, yeah--I use a right angle adjusting tool, to do this, invented by James, the J in JLD. I'll take a few pix later.