Physical Test for Nitro vs Truetone

[TTiimm]

I'm looking for a physical test to determine if an Eastman guitar is Nitrocellulos or not.

Approximate date the change to Truetone was made, serial numbers and contacting Eastman are understood. I am not looking for probably, however. I'm looking for an actual physical test, a way to know for sure.

My thought is that a bit of lacquer thinner on a Q-tip could be used to test the area under the pick guard and if it doesn't dissolve the finish then it isn't nitro. Does anyone think that will work? Is there any special type of lacquer thinner for nitro or will generic lacquer thinner work?  The guard will actually be changed in the near future so this could be done.

What about Truetone? Is there a way to test that isn't destructive or at least not visible?

Any thoughts appreciated.

[Vapour]

I can only add that both deet and picardin will 100% mess up Eastman's nitro (but possibly Truetone as well!)

[TTiimm]

I can only add that both deet and picardin will 100% mess up Eastman's nitro (but possibly Truetone as well!)

That's good to know and sort of the catalyst for why I asked.

I do a fair bit of cycling in the mountains and just picked up a fresh bottle of Picardin and a few tubes of zinc oxide sunscreen (ThinkSport). Not really keen on having either mess up the finish should I happen to cross contaminate.

Further relevant information warmly welcomed.

[REHII]

Here is a webpage that talks about how to tell if it’s nitro.
Alcohol, acetone, and lacquer thinner will dissolve nitro finish.
I don’t know what dissolves trutone.
This page says he can buff out the small mark made by the test in nitro.
I would test under a tuner.
But if the guitar sounds great does it matter?
What finish, is it “real” mahogany, is that rich lite or ebony,red,Sitka,alpine,German ,carpathian, engalmann ,lutz or moon.
Are those waverlys or pings?
I think in the future as materials get scarce guitar lovers will have to be more tolerant of new materials and techniques.
How does it sound and play?




http://www.frets.com/FretsPages/Luthier/...etest.html

[Pura Vida]

I'm not sure what substance would dissolve Nitro, but not Truetone poly (or vice versa), but I'm sure there's something out there that would work.  Definitely pick a hidden area, so you don't create any unwanted issues.  Good luck!

[John-K]

I did this with the finish on a 2020 Truetone finished mandolin. Acetone rubbed the finish right off off the inside of the F-holes but did not hurt it on the back or under the bridge. I have no idea why. Tread lightly.

[TTiimm]

Here is a webpage that talks about how to tell if it’s nitro.
Alcohol, acetone, and lacquer thinner will dissolve nitro finish.
I don’t know what dissolves trutone.
This page says he can buff out the small mark made by the test in nitro.
I would test under a tuner.
But if the guitar sounds great does it matter?
What finish, is it “real” mahogany, is that rich lite or ebony,red,Sitka,alpine,German ,carpathian, engalmann ,lutz or moon.
Are those waverlys or pings?
I think in the future as materials get scarce guitar lovers will have to be more tolerant of new materials and techniques.
How does it sound and play?




http://www.frets.com/FretsPages/Luthier/...etest.html

The type of finish matters to me. Some are more delicate than others. I would like to take my guitar to the park or car-camping. If sunscreen or insect repellent is going to damage one finish but not anotherr then I want to know that.

I'm actually in favor of moving completely away from nitro. There's no longer a valid excuse to use such a nasty product. Dana Bourgeois proved that. I would be pleased to find that my E10OM-TC is Truetone.

I appreciate the link. Thank you. It is exactly what I was looking for. I'll test when the pick guard is changed.

 

---

I did this with the finish on a 2020 Truetone finished mandolin. Acetone rubbed the finish right off off the inside of the F-holes but did not hurt it on the back or under the bridge. I have no idea why. Tread lightly.

The voice of experience. Thank you.

[REHII]

I can tell you bug spray is bad stuff.
Not sure why but it hates plastic and finishes.
I have seen guitar finish ruined by it.
I have a 1970 mustang that has wood grain looking plastic on the dash. 30 years ago a friend sprayed “off” while in the car. Everywhere it got on the plastic or plastic wood looked melted and bubbled. I had to replace all the plastic parts of the dash on the osssenger side.
When I’m at an outdoor jam or festival and I even smell bug spray I get freaked out about by guitar.
And as far as finishes on guitars, I do like nitro, it’s what I’m used to, but if something better comes along I will accept it!

[John-K]

I can tell you bug spray is bad stuff.
Not sure why but it hates plastic and finishes.
I have seen guitar finish ruined by it.
I have a 1970 mustang that has wood grain looking plastic on the dash. 30 years ago a friend sprayed “off” while in the car. Everywhere it got on the plastic or plastic wood looked melted and bubbled. I had to replace all the plastic parts of the dash on the osssenger side.
When I’m at an outdoor jam or festival and I even smell bug spray I get freaked out about by guitar.
And as far as finishes on guitars, I do like nitro, it’s what I’m used to, but if something better comes along I will accept it!

I wonder why leather bullies lacquer as well.

[TTiimm]

I can tell you bug spray is bad stuff.
Not sure why but it hates plastic and finishes.
I have seen guitar finish ruined by it.
I have a 1970 mustang that has wood grain looking plastic on the dash. 30 years ago a friend sprayed “off” while in the car. Everywhere it got on the plastic or plastic wood looked melted and bubbled. I had to replace all the plastic parts of the dash on the osssenger side.
When I’m at an outdoor jam or festival and I even smell bug spray I get freaked out about by guitar.
And as far as finishes on guitars, I do like nitro, it’s what I’m used to, but if something better comes along I will accept it!

I wonder why leather bullies lacquer as well. 

IIRC, something about the solvents used to make leather soft and supple.