A hairline top crack? (Pics)

Construction and repair of Classical Guitar and related instruments
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Arash Ahmadi
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Re: A hairline top crack? (Pics)

Post by Arash Ahmadi » Thu Jan 25, 2018 11:36 am

Some more pics here: https://files.fm/u/zt2yfs5t

I think it's easier to see it in these pics (especially pic named "cr"). I would appreciate your thoughts.
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Michael.N.
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Re: A hairline top crack? (Pics)

Post by Michael.N. » Thu Jan 25, 2018 11:54 am

That's not definitive. It does appear to cross a grain line but then it's quite possible that it's actually two cracks. A little like medical matters it's foolish to diagnose it through the internet, you really need to get it to a guitar doc.
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Arash Ahmadi
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Re: A hairline top crack? (Pics)

Post by Arash Ahmadi » Thu Jan 25, 2018 12:08 pm

Michael.N. wrote:
Thu Jan 25, 2018 11:54 am
That's not definitive. It does appear to cross a grain line but then it's quite possible that it's actually two cracks. A little like medical matters it's foolish to diagnose it through the internet, you really need to get it to a guitar doc.
You are right, thanks Michael!
To send light into the darkness of men's heart, such is the duty of the artist. (Robert Schumann)

SteveL123
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Re: A hairline top crack? (Pics)

Post by SteveL123 » Thu Jan 25, 2018 2:25 pm

Arash Ahmadi wrote:
Thu Jan 25, 2018 9:32 am
SteveL123 wrote:
Wed Jan 24, 2018 11:54 pm
Found this crack finding techniques:

"Put naphtha on the outside of the crack, all along the length. Then look inside with a mirror and flashlight. You'll see wet spruce."

Naphtha will evaporate and leave no trace.
Thanks Steve, it sounds a bit risky for this guitar. Does it work with all finishes?
I don't think it harms most guitar finishes but you should wait till a Luthier with experience with such procedure chimes in first. A readily available source of Naphtha is cigarette lighter fluid.

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Beowulf
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Re: A hairline top crack? (Pics)

Post by Beowulf » Thu Jan 25, 2018 2:36 pm

One thought: if this was not present when you purchased the guitar and given that it extends on both sides of the bridge (reaching the lower bout and the rosette), I would suspect a hairline crack in the top.
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Arash Ahmadi
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Re: A hairline top crack? (Pics)

Post by Arash Ahmadi » Thu Jan 25, 2018 8:26 pm

Beowulf wrote:
Thu Jan 25, 2018 2:36 pm
One thought: if this was not present when you purchased the guitar and given that it extends on both sides of the bridge (reaching the lower bout and the rosette), I would suspect a hairline crack in the top.
It's not on any sides but middle of guitar and it is visible (more in the latter) pics when zoomed in.
To send light into the darkness of men's heart, such is the duty of the artist. (Robert Schumann)

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Arash Ahmadi
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Re: A hairline top crack? (Pics)

Post by Arash Ahmadi » Thu Jan 25, 2018 8:28 pm

SteveL123 wrote:
Thu Jan 25, 2018 2:25 pm
Arash Ahmadi wrote:
Thu Jan 25, 2018 9:32 am
SteveL123 wrote:
Wed Jan 24, 2018 11:54 pm
Found this crack finding techniques:

"Put naphtha on the outside of the crack, all along the length. Then look inside with a mirror and flashlight. You'll see wet spruce."

Naphtha will evaporate and leave no trace.
Thanks Steve, it sounds a bit risky for this guitar. Does it work with all finishes?
I don't think it harms most guitar finishes but you should wait till a Luthier with experience with such procedure chimes in first. A readily available source of Naphtha is cigarette lighter fluid.
Sure, thanks!
To send light into the darkness of men's heart, such is the duty of the artist. (Robert Schumann)

SteveL123
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Re: A hairline top crack? (Pics)

Post by SteveL123 » Mon Jan 29, 2018 3:57 am

Arash Ahmadi wrote:
Thu Jan 25, 2018 9:32 am
SteveL123 wrote:
Wed Jan 24, 2018 11:54 pm
Found this crack finding techniques:

"Put naphtha on the outside of the crack, all along the length. Then look inside with a mirror and flashlight. You'll see wet spruce."

Naphtha will evaporate and leave no trace.
Thanks Steve, it sounds a bit risky for this guitar. Does it work with all finishes?
Per this viewtopic.php?f=11&t=117803 Naphtha is safe on French polish.

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Arash Ahmadi
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Re: A hairline top crack? (Pics)

Post by Arash Ahmadi » Wed Jan 31, 2018 5:45 pm

Update: I've shown my guitar to a local luthier and he thinks it's a so called "mirror crack" and I should wait 4-5 months to see how it turns out. I will keep it in the room with the humidifier.

Based on the talk I had with him, I've concluded that it's too risky to repair anyway... it makes me wonder if there's any safe way to repair it without affecting the sound.
To send light into the darkness of men's heart, such is the duty of the artist. (Robert Schumann)

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Arash Ahmadi
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Re: A hairline top crack? (Pics)

Post by Arash Ahmadi » Wed Jan 31, 2018 5:46 pm

SteveL123 wrote:
Mon Jan 29, 2018 3:57 am
Arash Ahmadi wrote:
Thu Jan 25, 2018 9:32 am
SteveL123 wrote:
Wed Jan 24, 2018 11:54 pm
Found this crack finding techniques:

"Put naphtha on the outside of the crack, all along the length. Then look inside with a mirror and flashlight. You'll see wet spruce."

Naphtha will evaporate and leave no trace.
Thanks Steve, it sounds a bit risky for this guitar. Does it work with all finishes?
Per this viewtopic.php?f=11&t=117803 Naphtha is safe on French polish.
Thanks!
To send light into the darkness of men's heart, such is the duty of the artist. (Robert Schumann)

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Arash Ahmadi
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Re: A hairline top crack? (Pics)

Post by Arash Ahmadi » Wed Jan 31, 2018 5:47 pm

By the way, I wonder if anybody is familiar with the "mirror crack" here.
To send light into the darkness of men's heart, such is the duty of the artist. (Robert Schumann)

oc chuck
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Re: A hairline top crack? (Pics)

Post by oc chuck » Wed Jan 31, 2018 6:32 pm

This is a test I was shown by two luthiers.

Lay the guitar on a table so there is a light reflection across the crack area.
Gently press on one side of the crack, 1/2" away. If there is a break or refraction
in the reflection at the crack, it may be in the wood. If no break or refraction,
it may be a finish crack.

It may not be 100% accurate, but it is a good indicator.

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Arash Ahmadi
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Re: A hairline top crack? (Pics)

Post by Arash Ahmadi » Wed Jan 31, 2018 6:53 pm

oc chuck wrote:
Wed Jan 31, 2018 6:32 pm
This is a test I was shown by two luthiers.

Lay the guitar on a table so there is a light reflection across the crack area.
Gently press on one side of the crack, 1/2" away. If there is a break or refraction
in the reflection at the crack, it may be in the wood. If no break or refraction,
it may be a finish crack.

It may not be 100% accurate, but it is a good indicator.
Thanks Chuck, I see but I am a bit too afraid to press it down as the top is very very thin. But I think I have a photo that is taken in the condition that you suggest. Here are the photos:
https://files.fm/u/ws5egafe
https://files.fm/u/j6eusa4g
https://files.fm/u/zt2yfs5t
To send light into the darkness of men's heart, such is the duty of the artist. (Robert Schumann)

Nikos_Greek
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Re: A hairline top crack? (Pics)

Post by Nikos_Greek » Wed Jan 31, 2018 7:26 pm

Hello Arash, have you contacted the luthier? I had a humidity problem with my guitar which thanks god is solved now and when I contacted my luthier he proposed to build another guitar for me straight away without me suggesting that. A serious luthier should be able to offer solutions to these problems although I understand the shipping would be a problem in your case.
Regards, Nikos

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Arash Ahmadi
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Re: A hairline top crack? (Pics)

Post by Arash Ahmadi » Wed Jan 31, 2018 7:41 pm

Nikos_Greek wrote:
Wed Jan 31, 2018 7:26 pm
Hello Arash, have you contacted the luthier? I had a humidity problem with my guitar which thanks god is solved now and when I contacted my luthier he proposed to build another guitar for me straight away without me suggesting that. A serious luthier should be able to offer solutions to these problems although I understand the shipping would be a problem in your case.
Regards, Nikos
Hi Nikos, building another guitar is certainly a great solution! I have contacted my luthier but he is not sure it's a crack.
To send light into the darkness of men's heart, such is the duty of the artist. (Robert Schumann)

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