Rust removal - Face Plate of 1964 Gibson Scout

[Resonator Guy]

Does anyone have any miracle solutions to rust on a face plate. I recently got a 1964 Gibson Scout. Advertised as not working and it wasn't but all it needed was a cap job. This amp hadn't been touched since it was built and it now looks and sounds great except....
The faceplate looks like it sat by a mist humidifier for years. There is a fine film of rust dots covering it. The silkscreening is still perfect under the golden red sheen. I have tried Lee Valley metal polish, Canadian Tire chrome cleaner, Nevr-Dull, along with micro cloths and 0000 steel wool (gently). They will all take a little off but not very much.
Any suggestions or am I doomed? Actually the rust looks like anodized aluminum or some such and goes quite well with the gold grill cloth, but I would like it gone.

[Chuck H]

The big hitch as I see it is that it will require too much abrasion to really get it off and likely remove your markings. If it IS rust (aluminum doesn't rust and I don't know what kind of plating it could be) there are products that will instantly oxidise rust into a blackend compound of carbon and chemical salts. Whether that might make removal easier I can't say.

[Resonator Guy]

Yep, it is rust, the face plate is part of the steel chassis. At least it is magnetic and can be soldered to.

[Chuck H]

I just plugged "rust dissolver" into google and got this:

Eastwood Rust Dissolver Gallon - Metal Rust Removal Products - Eastwood

Of course, try in a less visable area first to test for finish damage or paint removal.

[J M Fahey]

1) *Triple* confirm it's an iron faceplate , not aluminum, because the answer is very different from each other.
The chassis itself certainly is iron, but it might have a thin Aluminum plate over it (as in Blackface amps).
And Aluminum also corrodes, only in a different way.
2) forget abrasives of any kind; any strong enough to remove rust will attack the paint job.
3) if iron, start by wiping the front panel with some WD40 or similar.
It will soften rust. Let it work overnight.
Next day wipe with clean cotton swabs. Should remove an appreciable amount of rust, cotton swabs should appear orange spotted.
4) maybe it's enough. If so, apply some wax, not the abrasive car polishing type but floor/furniture type.
Will make surface bright again, partly hide rust spots and reasonably protect against future oxidation.
5) if not, wipe clean, then swab with cotton ball with drops of alcohol to degrease, then apply car type rust remover (phosphoric acid) just on rust spots with a QTip.
Let it work, wipe clean, check with magnifier.
"Dangerous" red rust becomes stable dull grey phosphate, much less visible.
If later waxed, becomes even less visible.

*or*, you can re-make it, from *this*:

to *this*:

[Chuck H]

OF COURSE Juan does his own custom silk screening. He probably also does his own dental work!

[J M Fahey]

Not *that* much ... and don't remind me of it, I've been to the dentist weekly for all of last month (ouch!!) getting ready for 5 implants (double ouch!!).
By the way, my former dentist *did* her own dental work, using mirrors. Crazy !!!
The restored panel I've shown above was re-drawn (Corel Draw?) by the amp owner and laser engraved on thin adhesive backed aluminum foil.
Only problem is that now it looks *too* new.
The amp lost 90% of its value (or so they say), so you'd better think it twice before removing Mojo ...... sorry !! ..... rust !!!!!

[Resonator Guy]

Thanks Chuck and Juan. I will try WD40 and see if that does anything, otherwise it stays rusty. It is too bad, because the tolex and grill cloth are perfect, and the amp now sounds terrific, even with the original 10" CTS speaker. The face plate is definitely steel and part of the bent steel chassis. This shot isn't great but my camera wont shoot around corners.
This will make a nice addition to my Gibson collection, if not the shiniest example.

[Resonator Guy]

Nearly Done - not good enough but nearly

I tried WD40 and it did a little, but since I don't want to strip the chassis to work with it, it is difficult. I got a new tin of Nevr-Dull and since it is cotton swabbing impregnated with something like WD40, I can use it every day with the amp all put together. The amp is a little bright and I will look at changing some cap values, or not play Fenders through it. The reverb however will need some work. It is very shrill. One book says to put a cap across the return feed of the reverb. I will have to figure out what that might mean in real English and give it a whirl. Here is a shot of the sort of finished product sitting in my music room. I will need to make some space for it. Believe it or not, I have got a lot of rust off of it.

[soundguruman]

Yes, it's called natural blue. It's an acid based cleaner that is frequently used on fiberglass.
But, it was discovered that it cleans metal rather well.
I dilute it 8:1 with water. 8 parts water one part NB.
Diluted with water it removes the rust, then it can be neutralized with baking soda in water.
(distilled water, I would recommend)
Then it should be dried with a hair dryer...or baked. You want to evaporate all the remaining water.
Of course it depends on the condition of the faceplate lettering, and how the lettering was applied.
I would have more faith if the lettering was baked powdercoat or engraved into the metal.

But no, once rust has penetrated the metal, there is no majic healer. The rust may be gone, but the metal is pitted.
There is a technique used in archeology, which electrolytically reverses the oxide. I am not familiar with "that."
(consult your local archeologist...)

We use this majic blue to take the oxide off scuba equipment and transmitter parts... It does not damage the metal, but leaves it nice and clean.

[Resonator Guy]

Since the faceplate is part of the chassis and has perfect lettering etc I don't think I would or could try this stuff.

[Bruce / Mission Amps]

Just don't use an abrasive or rub too hard or you'll attack the silkscreening too, assuming it is inked.

If you are sure it is steel, I'd try a little watered down naval jelly in a very small area and see what happens.

[Resonator Guy]

Thanks Bruce, I won't rub too hard. I will try some Naval Jelly if I can find a small package. It isn't anything like that Royal Jelly I used to see advertised for all sorts of health cures, is it?

[soundguruman]

Thanks Bruce, I won't rub too hard. I will try some Naval Jelly if I can find a small package. It isn't anything like that Royal Jelly I used to see advertised for all sorts of health cures, is it?

Navel jelly is much stronger and will take the paint off.
Phosphoric acid may be used as a "rust converter", by direct application to rusted iron, steel tools, or surfaces. The phosphoric acid converts reddish-brown iron(III) oxide, Fe2O3 (rust) to black ferric phosphate, FePO4.

"Rust converter" is sometimes a greenish liquid suitable for dipping (in the same sort of acid bath as is used for pickling metal), but it is more often formulated as a gel, commonly called naval jelly. It is sometimes sold under other names, such as "rust remover" or "rust killer". As a thick gel, it may be applied to sloping, vertical, or even overhead surfaces.

After treatment, the black ferric-phosphate coating can be scrubbed off, leaving a fresh metal surface. Multiple applications of phosphoric acid may be required to remove all rust. The black phosphate coating can also be left in place, where it will provide moderate further corrosion resistance (such protection is also provided by the superficially similar Parkerizing and blued electrochemical conversion coating processes).

[Resonator Guy]

Thank you soundguruman, I won't try it then.