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  #1  
Old 11-13-2012, 06:21 PM
joeguam joeguam is offline
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Default Ridiculously Horrible Lacquer Cracks/Finish - DIY Refinish?!?

Situational Note: I live on Guam and there are no professional luthier services available.

The lacquer that was put on by the original maker is really cracking and looks hideous! If you look closely at where the string ties to the bridge, you'll notice that there are now "channels" in the lacquer made by the strings - which look even worse when the strings are off.



There's also a nasty spiderweb of cracks on the back.



I've researched a lot but I'm wondering:
1. Is removing the finish fairly straight forward? Any advice (e.g. acetone, chemical stripping)?
2. Is spraying sealant and lacquer also doable?

I'm reasonably handy and have done all my installs and repairs on my instruments (because we have no other choice here on Guam), just wondering what others think.

Thanks in advance!

...
Joe
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  #2  
Old 11-13-2012, 09:36 PM
Wade Hampton Wade Hampton is offline
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Joe - Yes, it does appear from the photos that the builder applied the lacquer too thickly. If it's nitro-cellulose lacquer, it can be removed easily enough with the correct solvent.

Having never taken that step with any of my own instruments, I couldn't tell you which solvents to use, and since you live on an island in the Pacific Ocean there might be some difficulties in finding the correct solvents there. There seem to be ever-increasing restrictive regulations governing where and how those chemicals are shipped, mainly because most of them are so very toxic.

So you'll need to do your own research on that, and figure out what you can get locally that will do the job.

As for refinishing the guitar, you might want to look into learning how to apply French polish. It's easily done at a kitchen table, and has the additional benefit of being one of the very best-sounding guitar finishes that there is, mainly because it's so thin and light. French polish is more fragile than lacquer, so that's a factor to consider.

Good luck with this. Please let us know how you end up dealing with the situation.


Wade Hampton Miller

PS: My sister-in-law was stationed on Guam while she was in the US Air Force. She liked it well enough, but didn't like the poisonous brown tree snakes that have infested the island ever since being accidentally introduced shortly after WWII.






She told me that the snakes like to crawl into electrical transformers, which fries them and kills them but also blows out the equipment, causing countless power outages on a regular basis.

Ever have any encounters with those adorable creatures?
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Old 11-13-2012, 10:26 PM
joeguam joeguam is offline
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Quote:
Originally Posted by Wade Hampton View Post
My sister-in-law was stationed on Guam while she was in the US Air Force. She liked it well enough, but didn't like the poisonous brown tree snakes that have infested the island ever since being accidentally introduced shortly after WWII.

She told me that the snakes like to crawl into electrical transformers, which fries them and kills them but also blows out the equipment, causing countless power outages on a regular basis.

Ever have any encounters with those adorable creatures?

Wade, I lived in Arizona from 19-29 years old and you can quote me on this: "I'd rather live here on Guam with as many NON-VENOMOUS (See: http://www.fort.usgs.gov/resources/e...ces/faq.asp#q1) brown-tree snakes that we have here than live in the entire state of Arizona with one rattle snake that will kill you within minutes."

CNN, NatGeo and The Discovery Channel have made such a horror story of the brown-tree snake that it's ridiculous. If you visited Guam (which we'd love to have you!), you probably wouldn't ever see one - unless you went hiking or were in the jungle somehow. I've seen these snakes since I was a little boy, and they do not cause harm or have never even heard of a case where they've attacked a human. Almost every time, they're just looking for food, and yes, this means birds and the same prey other snakes eat.

But, your sister was right, they do have incidents where they cause power outages, mostly trying to catch birds on the power lines (because our lines are above ground, not buried). However, these are like once a year.
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  #4  
Old 11-13-2012, 10:29 PM
joeguam joeguam is offline
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Quote:
Originally Posted by Wade Hampton View Post
Joe - Yes, it does appear from the photos that the builder applied the lacquer too thickly. If it's nitro-cellulose lacquer, it can be removed easily enough with the correct solvent.

Having never taken that step with any of my own instruments, I couldn't tell you which solvents to use, and since you live on an island in the Pacific Ocean there might be some difficulties in finding the correct solvents there. There seem to be ever-increasing restrictive regulations governing where and how those chemicals are shipped, mainly because most of them are so very toxic.

So you'll need to do your own research on that, and figure out what you can get locally that will do the job.

As for refinishing the guitar, you might want to look into learning how to apply French polish. It's easily done at a kitchen table, and has the additional benefit of being one of the very best-sounding guitar finishes that there is, mainly because it's so thin and light. French polish is more fragile than lacquer, so that's a factor to consider.

Good luck with this. Please let us know how you end up dealing with the situation.


Wade Hampton Miller

Wade, thanks so much for the advice, I'll look into the French polish. Fortunately, I'm repairing and rebuilding a cheap classical guitar that was given to my mom as a gift from her brother in 1971. This guitar was found floating in a puddle out in the lawn after a real bad typhoon hit in 1996. The headstock and the sides were cracked and the top came unglued from the rest of the body due to the water and the string tension. This repair/restoration is more for sentimental reasons but it's giving me a great opportunity to practice fixing side cracks, regluing the top and...now French polishing!

We have a Home Depot here on island and they bring in all the same stuff you'll find on homedepot.com - the only obstacle is stock, so I might have to wait another 2 weeks if they're out. I'm only concerned about what types of chemicals to use that will remove the lacquer safely while not damaging the wood or the bindings. If anyone in this forum can give some advice I'd be so grateful.

Thanks again and I'll be sure to update this thread to hopefully help anyone else who may be thinking about doing the same thing.

...
Joe
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  #5  
Old 11-14-2012, 02:06 PM
Wade Hampton Wade Hampton is offline
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Joe, you might want to go check out Frets.com here: http://frets.com/

Read through that for what has to be one of the very finest sources of information about stringed instrument repair.

Another excellent resource is to go to the Custom Shop subforum on this forum. A lot of the guitar hand builders hang out at that subforum, so you'll probably get quicker and better answers to these technical questions there:

http://www.acousticguitarforum.com/f...splay.php?f=38

Hope this helps.


whm
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Old 11-14-2012, 05:06 PM
joeguam joeguam is offline
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Thanks! I've very familiar with frets.com, I think everyone who's tried a DIY repair has to give credit to that site!

I'll try to move my thread to the custom shop, any ideas how to switch it over? I'm new to AGF.
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Old 11-14-2012, 11:29 PM
Wade Hampton Wade Hampton is offline
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Quote:
Originally Posted by joeguam View Post
Thanks! I've very familiar with frets.com, I think everyone who's tried a DIY repair has to give credit to that site!

I'll try to move my thread to the custom shop, any ideas how to switch it over? I'm new to AGF.
There's no need to switch this thread over there, just go over there and start another thread asking the questions you need to ask.


whm
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  #8  
Old 11-15-2012, 05:06 AM
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Great conversations (and photos) about brown "non" poisonous tree snakes and guitar re-finishing
in Guam! My day is not complete without several visits to the AGF! Seriously! I'm smiling!
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  #9  
Old 11-17-2012, 03:44 PM
John Arnold John Arnold is offline
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You can use a chemical stripper, but lacquer thinner will work just fine. With either chemical, care must be taken to avoid applying it to any plastic parts, because they will melt.
Acetone evaporates so quickly that it becomes too tedious, especially when the finish is as thick as it looks in the photo.
BTW, applying more lacquer doesn't fix the checking.....it just makes it worse (as if you didn't already know). Applying more lacquer on top of old lacquer subjects it to 'expansion shock'...where the thinner swells the top surface of the lacquer, then it shrinks back, causing the checks. The same thing happens when lacquer is sprayed on older celluloid bindings and pickguards.
In addition, the thicker the lacquer film, the more likely it is to crack from thermal shocks.
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  #10  
Old 11-18-2012, 05:46 PM
joeguam joeguam is offline
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Thank you everyone for the suggestions, they're really appreciated! I was very successful in using only lacquer thinner to get 98% of the finish removed and down to bare wood. Fortunately, it seems like the bindings were first sealed with cyanoacralate so there's almost no damage done to them from the thinner.

I'll post pictures here shortly but the process seems to be coming along nicely. Special thanks to Wade for suggesting French Polishing, I found a great article on the process from Milburn Guitars:
http://milburnguitars.com/fpbannerframes.html)

...as well as some great youtube videos from a guy who also learned from the same sight:
http://www.youtube.com/playlist?list...2&feature=plcp

Most of the folks on this site probably already know about these resources, however, I'm posting these links just in case there's a newcomer like myself who stumbles upon this thread.

There were a few "defects" revealed once the lacquer was removed, but thankfully these are things I can repair myself. The next step is to lightly sand it clean and start the pore filling. But, just for the heck of it, and because I never had the chance when it was first made, I strung it up while it's bare wood and the sound is MUCH MORE IMPROVED!!

...now I have to decide if I even want to French Polish coat it back up to a high gloss again. Is a thinner matte/satin-style of finish possible with the French Polish process?

...
Joe
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  #11  
Old 11-19-2012, 07:28 PM
joeguam joeguam is offline
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As promised, here are the photos of the instrument after removing the lacquer. This is not the same instrument as in the photo of my first post, however, it's the same make and the same finish...only a much cheaper model which I decided to test on first.





Now that the wood is bare, the sound is much more amazing! Are there any thoughts on how I could preserve this sound improvement with a minimal finish/coating? Should I even French Polish it up to a high-gloss? Or, should I just spit coat it with 3 layers of shellac and fill the wood then keep it at that?

Appreciate any info!

...
Joe
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  #12  
Old 11-11-2013, 10:10 PM
joeguam joeguam is offline
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Just to finally come full circle on this thread, I've started the process to refinish this ukulele. I'm documenting and photographing the steps in this thread:
Refinishing Thread: Curly Koa Ukulele (Z-Poxy/Minwax Wipe-On Poly)

Thank you all so much for your advice, I will forever be grateful whenever I pick this ukulele up to make music!

...
Joe
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