My National guitar is a treasured personal artifact, but it was crusted with 17 years of crud. I tried a lot of stuff to get it clean, and in the end Simichrome did the job.
I have treasured this guitar, and I've played the shit out of this guitar. One thing I've never been able to do is clean this guitar. I have tried and tried and tried to keep it shiny and nice, but guitars are made for playing. Skin oils seem to stick to the "German Silver" nickel/steel body like mad. Friends would come over to "jam" and just leave another layer of human gunk on it.
I started with the National website:
To clean a nickel body National Guitar or nickel body National Guitar parts, use a non-ammoniated liquid glass cleaner or white vinegar. For stubborn stains, use a chrome polish. One your National Guitar is in pristine condition, you may also use a high grade wax with carnuba in it. Replace that wax as needed. We recommend that you wipe down you National Guitar after each use.
This was of little help. I had layers upon layers of crud. I tried Brasso, Weenol, and about 1/2 dozen other pastes and polishes. Nothing seemed to work. The guitar got worse and worse.
All the gentle cleaning solutions just smudged things up more. Brasso left extra crap on the guitar. Weenol left microfine scratches in the finish, and the small spot where I'd tried it looked bad. I was considering trying highly caustic Eagle 1 Chrome Wheel Cleaner, when a friend suggested Simichrome. Simichrome is a german metal polishing compound that looks very similar to Weenol. Consistency wise it is perhaps a bit more liquid-y and a bit less jewelers rouge-y than the Weenol. Simichrome did the job really, really well.
There are some stains the Simichrome can't get out, but for a very heavy guitar with 2 decades of wear and tear on it I think it looks great.
Simichrome metal polishing compound via Amazon
