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Hoffman Amps Forum image Author Topic: This one hurts - a rust question... (Amp Related!)  (Read 6540 times)

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Offline BobRuth

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This one hurts - a rust question... (Amp Related!)
« on: June 18, 2015, 09:44:33 am »
As I said above, this one hurts.   I have been undergoing a move over the last week and that has included a LOT of throwing out/thinning down and getting the keepers moved over.  One of my amps I thought was safe in the storage cabinet in my garage.  Off of the floor level... has been there for some time (as in a few years!).   This is a 1961 Ampeg Reverberocket (6SL6, 6SN7, 6V6 5Y3 version)... I think it was a fairly early reverb guitar amp.  It was in bad shape when I got it....well it is a little worse now.

It looks like a rat got in the garage and dribbled on the control panel...  causing fairly small..but easily visible tracks of rust.  I checked on fliptops and the guy tells me that this one did not have a faceplate... that is was printed right on the chromed chassis.

What I am wondering is, does anyone have any ideas for handling rust like this?   I know it will never be normal...but are there any treatment techniques that can at least remove the rust that is there?   I dont think grinding is  a good idea.... but, short of trying to find another chassis (and I know nothing about silk-screening!), is there another way to at least help it a little bit?

Offline Toxophilite

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Re: This one hurts - a rust question... (Amp Related!)
« Reply #1 on: June 18, 2015, 12:41:32 pm »
You could tape around the areas and lightly steel wool them off, or use tiny pieces of fine sandpaper glued to a narrow stick

If it goes through numbers etc you should probably just wash it and live with it
I think getting a new chassis is pretty extreme for what really amounts to a little cosmetic damage
You can't hear how nice an amp looks
Personally I like a little character and wear in my amps and guitars

Offline thermion

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Re: This one hurts - a rust question... (Amp Related!)
« Reply #2 on: June 18, 2015, 01:54:03 pm »
Love those reverberockets!
Maybe try naval jelly?

Offline BobRuth

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Re: This one hurts - a rust question... (Amp Related!)
« Reply #3 on: June 18, 2015, 02:11:47 pm »
You know, I was thinking on the "character" angle after I left that....

It does indeed run through the printed content....

I think the safest thing I can do is probably (as suggested) tape it off and steel wool it to knock off the crusty rust then bring it in the house and give it "my side of the bed" to protect it here-on-in.  I'd rather not use anything that might soften the paint on the panel....   of course....tape can stick to it.....  *sigh*

oh well....

Offline x44d80

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Re: This one hurts - a rust question... (Amp Related!)
« Reply #4 on: June 18, 2015, 06:03:27 pm »
I don't like evasive procedures on finished metal.  If this was my chassis I'd use a rust converter which would turn the rust a blackish color or remove the rust with "Electrolysis" which is using a battery charger and a bucket of water and lye soap, not a great option unless all the electronics were removed.  Acid rust remover like Naval Jelly could work but might effect the non-rusted metal if left on it.

Offline AZJimC

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Re: This one hurts - a rust question... (Amp Related!)
« Reply #5 on: June 19, 2015, 02:37:42 am »
I have a '67 Gemini II...(Someone made into a head) . and the paint easily wipes off on this one..... I thought about getting a pin striping tool to replace the straight lines, maybe some decal numbers? It's got me afraid to clean it with any chemical. I thought about taking photos of it, and cleaning it up and get a visually artistic person to recreate it.

I know your pain..

Jim

Offline Toxophilite

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Re: This one hurts - a rust question... (Amp Related!)
« Reply #6 on: June 19, 2015, 11:21:12 am »
People must have some mint looking amps out there!
Mine have been dragged around to so many gigs they all are beat to hell!!
But still sound great
You could even scrape rust off(if it's not too deeply embedded) with a small piece of wood (say 3 or 4 times the size of a toothpick) pared down to a spatulate, chisel sort of shape, won't scratch the metal but strong enough to scrape off rust. With steel wool you'll have to be more careful


i think rust converter or any electrical procedure would be  definitely removing EVERYTHING from the face plate/chassis, except the metal
I still say clean it so it's hygenic and enjoy the fact that it has some history and a good rat pee story!!!

Offline BobRuth

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Re: This one hurts - a rust question... (Amp Related!)
« Reply #7 on: June 19, 2015, 02:19:13 pm »
I guess I should be looking for away to work a "ProCo Rat" pedal in here somewhere......

Offline Crispy

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Re: This one hurts - a rust question... (Amp Related!)
« Reply #8 on: June 27, 2015, 09:39:26 pm »
Just buff it off with some fine rubbing compound or toothpaste (Crest or Colgate original formula's work well, no gels or whitening stuff). Stay off the printing or use a VERY light touch on it. It helps if you strip the panel of parts first.
If there's a 50-50 chance something can go wrong, 9 times out of 10, it will.

Offline xm52

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Re: This one hurts - a rust question... (Amp Related!)
« Reply #9 on: July 01, 2015, 02:46:15 pm »
Autosol (http://www.leevalley.com/US/wood/page.aspx?p=67014&cat=1,43415,43439,67014) is cream metal polish that removes rust and leaves a wax protective coat. It works very well on chrome chassis. Be very careful with the lettering, it will remove the paint in a heartbeat. This will work well on your Ampeg chassis.


For more problematic cases, Restore (http://www.leevalley.com/US/wood/page.aspx?p=66065&cat=1,43415,43439) works well. Being a gel, you can apply it to vertical surfaces and let it work. Another liquid rust conversion product that I use is called Evapo-Rust. It's available in some hardware stores.


If you want to coat metal after cleaning, Evershield (http://www.aircraftspruce.com/catalog/cspages/evershield.php) is amazing. It's a two part wipe/brush/spray on ceramic coating. It dries thin and clear. I usually apply a few coats but it dried quickly. It seals the metal and never seems to yellow. They use this stuff to protect propellers on aircraft. That gives you an indication of how tough it is. The down side is that it's expensive but it spreads well so you don't use a lot.



OOPS: had the wrong link for Evershield at AIRCRAFT SPRUCE, fixed now.
« Last Edit: July 08, 2015, 12:47:58 pm by xm52 »

Offline birt

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Re: This one hurts - a rust question... (Amp Related!)
« Reply #10 on: July 03, 2015, 05:11:00 am »
most of the time when i deal with rust on old (painted) metal i just clean it so there is no rust "on top" and then rub it with WD40. this leaves a film and prevents it from rusting more. however the WD40 might give a different shine to the chrome. i never tried it on chrome.


Bert

Offline EL34

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Re: This one hurts - a rust question... (Amp Related!)
« Reply #11 on: July 03, 2015, 05:36:44 pm »
I just ordered some of this stuff
Not sure how well it works yet
http://www.amazon.com/gp/product/B000C016OC?psc=1&redirect=true&ref_=oh_aui_detailpage_o00_s00


Offline PRR

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Re: This one hurts - a rust question... (Amp Related!)
« Reply #12 on: July 03, 2015, 11:24:28 pm »
> this stuff

Plain old Naval Jelly.

I never saw it with LockTite's name, but they say "known and trusted for decades" so gotta be the same stuff.

I think it is weak. Never happy with results.

You can buy straight (non-jelly) Phosphoric Acid at the car-parts as "Metal Prep". One stage in getting paint to stick to car steel is to seal the inevitable loose red oxide with harder black oxide.

Go over to Tractor Supply and find Rust Kutter. Again Phos Acid with a trace of gel in convenient spray. If your 1967 tractor has been out in the rain for 48 years you'll find uses for it.

Phosphoric acid is rough on the skin. Not "instant burn", but a slow burn which takes a long time to heal. Wash-up.

Coca-Cola has a small shot of Phosphoric Acid. If you have a car with a real-Chrome bumper, rust-pocked, get a wad of aluminum foil and a can of Coke, rub well. The foil will scrub rust, not metal. There may also be an electro-chemical action here with the Cr, Al, and Coke. The Coke lubricates your rubbing and the Phos Acid seals the rust. Finally you get some Aluminum in the pits which (for a while) looks silvery instead of rusty-red.

None of these will *remove* more rust than a stiff toothbrush would. They convert the soft red oxide to a tougher black oxide which sticks better and won't "grow" as fast. The main use is to get a car surface you can *paint* over, without the rust coming back again every few years.

If it is a rusty amp, rusty because of bad storage or extended damp climate, the obvious approach is to don't store it badly. If you EVER feel damp on the surface, rust won't sleep. I keep a hygrometer in the cellar and dehumidify to 70% RH in the main space, so it never gets to 99% in the cool damp corners. (Not so much for rust but for fungus.)

WD-40 is a mild solvent and short-term lubricant. Just fancy kerosene. It WILL evaporate in weeks or months. That squeaky hinge WILL squeak again (they rely on repeat sales). If it shines your metal, fine, but then take the residue off with alcohol and apply paste-wax or something that will last.
« Last Edit: July 03, 2015, 11:28:56 pm by PRR »

Offline Crispy

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Re: This one hurts - a rust question... (Amp Related!)
« Reply #13 on: July 10, 2015, 09:26:45 pm »
If it wasn't such a pain in the ass to put a picture on this site, I'd show you what a little toothpaste and a soft cloth can do. It works.
If there's a 50-50 chance something can go wrong, 9 times out of 10, it will.

Offline sluckey

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Re: This one hurts - a rust question... (Amp Related!)
« Reply #14 on: July 10, 2015, 09:35:15 pm »
What do you find so painful about putting a picture on this site? It's very straightforward from my computer.
A schematic, layout, and hi-rez pics are very useful for troubleshooting your amp. Don't wait to be asked. JUST DO IT!

Offline EL34

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Re: This one hurts - a rust question... (Amp Related!)
« Reply #15 on: July 11, 2015, 06:33:42 am »
I received the Loctite naval jelly I showed in post #12
It's a pink thick jelly


It works great.


You need gloves and a well ventilated area




 


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