Nitro

[chico]

here is a close up of the checking area seen in the reflective part of the photo on the horn.

[smurph1]

That looks like checking to me.. but I'm a hillbilly..

[yuominae]

Just to add my .02. I bought a 2005 Gibby LP in Japan, which I sold again in 2011. I gave it a good inspection before sending it off and was horrified to find that the top was full of hairline cracks. They were only visible under the right angle, but they were everywhere.

My 89 H150 hasn't got that (it's only been in Japan for a year so far though).

 

Maybe Gibby's just check more easily?

[TalismanRich]

GuitarGarage...

 

A couple of things about nitro lacquer. First, be careful with NC. Its explosive when its dried. Smokeless powders is mostly nitrocel. Most NC grades for wood working are the highly nitrated grades. They will be the least stable form. When nitrocellulose aka cellulose nitrate decomposes, it releases nitrite (NO2) and nitrous acid (among other things). That's why the metal parts near celluloid parts will pit and turn green. Decomposition is accelerated by exposure to UV light. The UV light will cause it to yellow.

 

When you look at NC lacquers components, the plasticizers will be things like phthalates, or various alkyd resins. The compounds you mentioned below are all solvents. Most of the ones mentioned are quite flammable, so under no circumstances should you be smoking anywhere near this stuff. Also, its good to have plenty of ventilation when you spray. A buildup of fumes in a basement near a furnace or water heater is a nice way to blow up a house.

 

Isopropyly Alcohol

n-Butyl Alcohol

Methyl Ethyl Ketone

n-Xylene

1-Methoxy 2-Propanol Acetate

Toluene

n-Butyl Acetate

Xylenes (Dimethyl Benzenes)

Checking in the finish can be forced by large changes in temperature. The NC will expand and contract at a different rate from the wood, If the film is especially brittle, it will check even faster, as long as it is sufficiently dry.