how is this for rust?

[boogieslayer]

at what point is it too rusty and needs refurbishing or replacing?
is this too much rust? should i be worried?

 

[av8or3]

You are kidding, Right?

I certainly hope so.....
Jim

 

[boogieslayer]

i wouldnt buy it after the other topic here about rust lol

 

[Boogiebabies]

I remember the amp being from Florida at one time.
Ocean spray is murder on iron. It would have been better of
in Buffalo.

 

[emperor_black]

I bought a new amp and the transformer has rust on it even though the guy's in Arizona! Began researching on the internet which lead to Mercury magnetics' article about rusty transformers. Bottomline, a rusty transformer is a sign that its made of good iron and rust actually helps tone not take it away.

I'm just gonna leave the rust on my amp as it it...

http://mercurymagnetics.com/pages/news/VGmag/VGAug09Hamernik.pdf

 

[av8or3]

I bought a new amp and the transformer has rust on it even though the guy's in Arizona! Began researching on the internet which lead to Mercury magnetics' article about rusty transformers. Bottomline, a rusty transformer is a sign that its made of good iron and rust actually helps tone not take it away.

I'm just gonna leave the rust on my amp as it it...

http://mercurymagnetics.com/pages/news/VGmag/VGAug09Hamernik.pdf

I read the article and am blown away. I have read other articles (none I can post for you unfortunately) that imply just the oposite. That the rust indicates a breakdown in the laquer/varnish that provides the insulation between the plates and allows eddy currents to set up in the field that reduce the performance of the transformer.
I can completely agree that it would be the wrong to try and sand off the rust, however.
Kind of like politics, which side of the aisle are you on? :lol:
Oh well, live and learn.
Jim

 

[emperor_black]

Here's another question answered about rusty transformers...for the electrical engineers among us.

Transformer Rust -- Friend or Foe?

Question: I heard that rust is bad for my transformers. I’m being told that rust causes an increase in eddy current losses which will heat up and further damage my transformer. Rusty transformers will also hurt my tone, so I must remove the rust or replace the transformers to make my amp operate properly and extend its life.

Answer: Nothing could be further from the truth. While iron possesses the necessary magnetic properties, it is also electrically conductive. Eddy currents are circulating currents in the core induced by a magnetic field emitted by the energized primary winding of the transformer. These electric currents are undesirable. The core is acting much like a shorted secondary winding. They are power-robbing losses that convert your guitar playing (input power) into heat that beats up your transformer. This effect is certainly not helping your tone!

On the other hand, rust (iron oxide) is a nonconductor of electric current. The high resistivity of rust reduces eddy current losses. Since iron is also a conductor of electric current and the goal here is to minimize eddy currents, which is why the construction of the core is made up of a stack of thin plates of iron (laminations) which are insulated from each other by an oxide (rust-like) coating. This confines the eddy currents and prevents them from circulating between the laminations. The higher resistance created results in a reduction of power losses within the core.

What’s this mean in plain English? Back in the early years, manufacturers of laminations intentionally exposed their iron to moist air to encourage rust to naturally form on the surfaces as an insulator! Like a fine patina on an antique bronze the rust on your transformer could be viewed as badge of honor. Assuming that your transformer doesn't have other problems like coil damage from excessive moisture exposure (common with paper bobbins), you can actually expect some improvements in output transformer tone and lower losses in power transformers as rust develops.

If you are still bothered by the cosmetic aspect of rust, never scrape off the rust to the point of exposing bare metal because you will bring back those nasty eddy currents. Instead, brush off the loose particles and re-paint the area with varnish. If you want to send your transformer to Mercury, we can re-dip it in varnish and bake it for a small fee. Transformer evaluations are always no charge providing you cover the shipping costs to and from Mercury.

 

[JOEY B.]

^^^^^^ All this theory sounds good. But if I were looking to purchase this amp, I would have to wonder what kind of shape the pots, jacks, and switches are in, being that the transformers were sealed from the factory. :?:

The crazy thing about all this is that someone will read this and try to sell their Boogie for more money because of the "road worn" transformers that give better tone. Stranger things have happened. I sneer every time I read about the "tone sucking" graphic EQ on the C+. To each their own, I guess. :roll:

 

[av8or3]

I'll never buy a rusty civil war relic, if it's a guitar amplifier anyway, no matter what anybody says.
Show's neglect, disrespect and I won't be the one to bring it back from the dead,period. :shock:
Jim

 

[emperor_black]

For what its worth...

This is my Bogner's rusty transformer. I sent an email asking about it and was advised to wipe off the rust with wd-40. :roll:

 

[LerxstLee]

Just a tip I learned from Gerald Weber. If you take rustoleom paint, from a can, I would use black, and put a LIGHT coating around the laminates with a small art brush, and let it dry it may prevent further degredation. I have done this on a few transformers in much worse shape then the one in question . If the transformer is still working fine this might help stop the speed and depth of the rust. There is a light coating of laquer but that is usually shed quickly from heat. You need two elements for rust to develop, (H2O) and (O) oxygen, In the case where the manufacture said wipe it of with wd40, as long as it was not saturated it would be another great idea. The object is to coat not saturate the outside laminates, let it dry, and hopefully it will not let more water and air get inside thus ruining the transformer. Some of my best old amps had transformers with a ton of rust on them, I never tried to brush them clean or use sandpaper, I simply tried what was recomended from a top repair person and so far I have not had a problem doing this. Lightly coat, do not saturate is the key. In the first picture I do not think it would hurt to paint the bell cover either. Check some more sources but there are plenty of great amps out there that have rust on the laminates.
/cheers

 

[emperor_black]

Thank you very much for your inputs. A first hand experience always helps. A while ago, I had purchased a spray from Lowes which is a clear enamel. I had painted a bench, brown, but I wanted a little shine and this clear enamel was recommended. Anyway, on the can, it say "Protects against rust". What's your suggestion using that product? I will wipe off the rust using wd-40. Then spray a light coat of the clear enamel over the entire transformer. Its very quick drying too.

thanks!
Sam

 

[LerxstLee]

My only hesitation on wiping it off with wd40 would be the problem with the paint adhering to the surface after
it has the "oily" residue left from the wd40. Wd40 does evaporate for the most part, I am not familiar with its use on the
transformer, that said I can conclude that once applied it would continue by itself to inhibit further rusting of the laminates.
Thus no need to spray over it. You can use the spray by simply spraying it in a cap and then painting it on. If you chose that option. I would use the wd40 as recomended by the manufacturer and wipe the laminates. I would expect that will give you the results you would want as you have caught this so early. Call bogner again and ask about painting over the laminates after the wd40 would be your best bet. I still think that bogner's experience would tell them that the wd40 will stop humidity and oxygen from causing further rusting as there will be the protection left from the wd40. I would not over apply it, you do not want to saturate it.
/cheers

 

[LerxstLee]

I'll never buy a rusty civil war relic, if it's a guitar amplifier anyway, no matter what anybody says.
Show's neglect, disrespect and I won't be the one to bring it back from the dead,period. :shock:
Jim

I like the saying, do not store your amp where you would not sleep. Like a humid basement or some attics.
Yet rust on the surface of a transformer seldom if ever causes problems. I have a tiny terror that has small spots of rust that were there when I received it new. Take a good look at some of the best amps you have heard and you will almost always see some amounts of rust on the laminates without harm to any of the components. Some cases are worse than others and some surely need a repair/replacement for sure. I have seen more problems from wires coming from the transformer that are covered with cloth, while the transformer may look a bit ugly it is 100% fine. A simple covering with
rustoleum paint with the grain seems to stop any further "problems" from occuring in transformers over the last 20 years of repairing amps. If someone loves vintage amps and some rust on the laminates stops them from buying it let me know I will gladly make that purchase. Since you are putting apples against oranges I will say do you bring your car back to midas a week later because there is rust already forming on the exhuast pipes?
/cheers