The instrument in question is a Takamine classical with a thick glossy finish on it. So far so good, but Pledge might have a solvent content--it will take the dead bugs off of the nose of a white car, for instance.
Good call on the "Frets.com" stuff. Frank has great advice.
In general, any synthetic non-curing oil will invade cracks and keep traveling on or in the wood until it solidifies or wears away or evaporates or whatever - and may do visual or physical harm in the process. Some of the worst synthetic oils - like silicone - literally never solidify or evaporate. That's why they're so bad for the environment (and also - guitars)
In other words, natural oil absorbs oxygen and polymerizes or otherwise solidifies... and some synthetic oils (AKA synthetic varnishes and the like) have things like Cobalt added to them to make them solidify. So - they may go on and provide a sheen, but it's because they've hardened into a glossy solid substrate.
In general, it's a misnomer that woods need to be "fed". Woods can't be "fed" as they're long since dead. A good finish is the best thing for wood so just do what you can to keep the finish in good shape.
If you really want to spruce up your guitar and the finish is in good shape - try some Meguiars #7 show car glaze. Follow the instructions carefully. Tons and tons of guitar makers use it. Practice on something till you get the hang of it, but it's not hard to use. Or use the Novus - but it's harder to find.
You get one chance to enjoy this day, but if you're doing it right, that's enough.
Comments
Some people have suggested the old Gibson pump polish is great and safe on most finishes.
http://www.frets.com/FRETSPages/Musicia ... ing01.html
Also, there's a lot of useful tips and info on the index part of the site.
Here's resources for players: http://frets.com/FRETSPages/pagelist.html#Musician
...and some observations about the Selmer style guitars:
http://frets.com/FRETSPages/Musician/Gu ... erfix.html
In general, any synthetic non-curing oil will invade cracks and keep traveling on or in the wood until it solidifies or wears away or evaporates or whatever - and may do visual or physical harm in the process. Some of the worst synthetic oils - like silicone - literally never solidify or evaporate. That's why they're so bad for the environment (and also - guitars)
In other words, natural oil absorbs oxygen and polymerizes or otherwise solidifies... and some synthetic oils (AKA synthetic varnishes and the like) have things like Cobalt added to them to make them solidify. So - they may go on and provide a sheen, but it's because they've hardened into a glossy solid substrate.
In general, it's a misnomer that woods need to be "fed". Woods can't be "fed" as they're long since dead. A good finish is the best thing for wood so just do what you can to keep the finish in good shape.
If you really want to spruce up your guitar and the finish is in good shape - try some Meguiars #7 show car glaze. Follow the instructions carefully. Tons and tons of guitar makers use it. Practice on something till you get the hang of it, but it's not hard to use. Or use the Novus - but it's harder to find.