Is the area behind the bridge on acoustic guitars always build flat?

[Domi7]

Dear fellows,

I just bought a b-quality Fame A-11. (at www,musicstore.de)

The problem/reason for b-quality state described by the shop is in fact very minor, and for the price (I paid half or the regular amount) it seems a great guitar, although top and bracing seems really thin. Sound is great, just the low E string has some less good sustain on a few frets (strong resonance, but more quickly declining sound) .

Setup is very low, but still great if it stays like that.

Now my main concern:
The surface behind the bridge is not flat, but raised in the center. To a certain extent, I think it's a normal because of string tension,
BUT ... The underside of the bridge follows that roundness, so I wonder if the surface is a bit round on purpose,
or the whole guitar top is not well made.
Also in front of the bridge there is some roundness (although less than behind)
Also the backside of the bridge has detached from the top on a very small surface (just a few millimeters into the bridge and maybe 6 mm wide.
(which I could certainly fix)

So do you think,...
1) was the top built like that on purpose and will probably stay more or less like that?
or
2) Did the top warp already and will warp more in the future (and then worsen the instrument)?

Any help is greatly appreciated,
cheers,
Dominique




PS. I think it was worse with the strings on.
PS2 I have problems with the image posting. Though, if here I right click on the icon and choose open image in new tab, my photo will be shown

[zombywoof]

"Flattop" is a misnomer used to differentiate from a guitar with a carved or pressed arched top. Generally, guitars are built with a radiused top.

[Domi7]

thanks a lot, zombywoof, I wasn't even aware of that!

[John Arnold]

The fact that the top has some positive arch in front of the bridge indicates that it has some built-in radius. The radius on the bottom of the bridge is also an indication. String tension tends to press in on the top in that area. Tops that start out flat will tend to end up sunken in between the bridge and the soundhole.

[Retired1]

Domi7 - you're bridge is separating from the top - no good - if possible go back to the shop and look at similar guitars while returning it - that small delam may the beginning of a real issue

[donlyn]

Is the area behind the bridge on acoustic guitars always build flat?

Not only that, but the guitar back may have a radius too.

Don
.

[KevinH]

Originally Posted by Retired1

Domi7 - you're bridge is separating from the top - no good - if possible go back to the shop and look at similar guitars while returning it - that small delam may the beginning of a real issue

But usually easy to fix if it is an issue. If it is a small area and you like the guitar otherwise, I’d just watch it and see. Could be lifting or could be a gap in the glue. Slide a piece of paper in the gap, mark the back of the bride with a pencil and recheck in a month or two. I did that on my Martin 00. It cost around $50 or $60 to have it fixed.

[lar]

If you loosen all the strings (remove all tension), does the top stay in that curved shape that you describe?

[Malcolm Kindnes]

It's perfectly normal for the guitar top to be slightly curved. The bridge may be lifting, but it is probably just a slight gap in the glue. Just keep an eye on it, I have a guitar with this issue and it hasn't changed in 20 years.

[TiffanyGuitar]

Get your bridge checked. Having it reglued is not a big deal. I do not
Recommend just keeping an eye on it. If they come
Loose, it can sometimes be with some force and cause damage to the top.

How old is the guitar? It is normal for some bellying behind the bridge to occur.

[Domi7]

Dear fellows,

thank you for all of your replies!
I let the guitar relax a bit without strings to see how it is without string tension while thinking about what to do.

Regarding the bridge:
As I already had repaired a few ukuleles and removed and reglued bridges, I dared adding string tension again, and trying to see if and how far my feeler gauge would go underneath the bridge. (It was the best item I could find here for that job). I could scratch out some more soft glue, applied heat with a heat gun, while covering the top with tape and worked hide glue in, then removed the string tension and cleaned everything up.
It seems to have worked well.

Two days later ( I was cautious) I put the strings on again. The radius behind the bridge is a bit higher with string tension, it seems, and it doesn't look perfectly round, but maybe that's asked too much for a 249 Euro guitar.
The thing for not wanting to return it: It was a model that was declared B-ware and I got it for only half of the price while it is great for the price and I'm confident that I can fix - or at least improve on the very few flaws.

Reagrding the weak notes on the low E-string:
Now I will try slightly lighter strings on it and think about sealing the inside which would also increase weight a tiny bit and stiffen the top (by probably just a minuscule amount), but I recently read a post here by Alan Carruth about string and top impedance and think that this could lessen my weak note problem (or rather strong note that declines too quickly).

I really like the sound of the guitar, playability, handling otherwise.

Best regards and thank you for all your input,
Dominique