Electric Kettle Rust

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Douglefish

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I am using an Electric Boil Keggle made from a 1 in stainless nut and a 5500W ULD heating element. I'm getting rust on the base of the heating element, and some is transferring over to the stainless steel. Just wanted to get peoples thoughts.

Is this a problem?
Is there a way to avoid this?

Thanks for the help!
 
Definitely a problem as wort is acidic and will dissolve the rust giving your beer an iron/metallic taste. Try cleaning the rust off and treating the area with a rust converter. This will give you an insoluble protective layer. You may have to do this several times.
 
You have a couple solutions you can try. Some folks have cleaned up the rust on the element base and the kettle, then coated the element base with silicone sealant. The solution I chose to use was to buy a magnesium fire starter at a camping store, cut it in half, and bolt it to the inside of my HLT (where I had the problem). I used a stainless steel 1/4" bolt, drilled a hole in the kettle, put the bolt in from the outside, silver soldered it to seal it, then put the magnesium block on the protruding threads inside the kettle and tightened it down with a stainless nut.

The magnesium is a sacrificial anode, and should prevent the steel of the element base from corroding, because it is a more active metal and will corrode first. You could also use a piece of aluminum, but I chose magnesium because I don't want aluminum ions in my water or beer, but don't care about magnesium ions.

Another choice would be to replace the element with a stainless steel one. Lowes has some, though I am not sure if the base is stainless or not. Next time I'm going there, I'll take a magnet and see.
 
Do you have any recommendations as to what rust converter to use?

Thanks again
 
From what I've read, the base of almost every element is mild steel. This is independent of the element's material. You could use more of the JB weld you used to pot your connections, and just create a thin protective layer.....or just go with the food grade silicone sealant. A sacrificial anode sounds complicated, but it isn't....you already have to drill holes in the pot...I think even copper will work :mug:
 
From what I've read, the base of almost every element is mild steel. This is independent of the element's material. You could use more of the JB weld you used to pot your connections, and just create a thin protective layer.....or just go with the food grade silicone sealant. A sacrificial anode sounds complicated, but it isn't....you already have to drill holes in the pot...I think even copper will work :mug:

So, a copper dip tube would solve the problems? Or it actually has to touch the mild steel?
 
Actually, the idea is that you need to have 2 things:

1) An electrical pathway for electrons to travel...
2) The sacrificial anode must be more active than the metal you are protecting

Not sure if copper is less active than mild steel, especially once it forms an oxide layer.....

Aluminum is hella cheap and easy to drill...I say go for aluminum :)
 
So the Coghlan's firestarters(most common brand) are composed of:
97.24% Magnesium
1.21% Zinc
1.11% Manganese
0.44% Iron

The electrical pathway is the water.
Still unclear if I have to bolt it in, or can I just toss in the firestarter and fish it out upon cleanup?
 
I bolted mine in place. This assured me of electrical contact. Take a look at "Cathodic Protection" on Wikipedia. The electrical path is through the metals and through the water in the pot. Pity, since I always wanted to bolt a chunk of zinc in the trunk of my car and prevent rusting.

Copper isn't active enough to protect steel according to the activity table in Wiki, but aluminum is just barely active enough.
 
Does the anode work when not under water? For example, after I drain the kettle if the element base is still wet would the anode keep it from rusting? Also. Would the anode work if just thrown into the kettle? Trying to understand how it works, thanks
 
They'd pretty much have to be touching in your example, with a thin film of water between em. Why not wipe it out when you're done?
 
Does the anode work when not under water? For example, after I drain the kettle if the element base is still wet would the anode keep it from rusting? Also. Would the anode work if just thrown into the kettle? Trying to understand how it works, thanks

It's an electrical process, the sacrificial anode can be mounted to the exterior of the pot no problems. On steel ships and other steel structured like bridges, zinc plates are bolted on the dry side of the hull or wall where they can be serviced. 2 small bolts to attach it to the pot will be plenty. If you can get the sacrificial metal to push flush up against the kettle it would be better yet.
 
It's an electrical process, the sacrificial anode can be mounted to the exterior of the pot no problems. On steel ships and other steel structured like bridges, zinc plates are bolted on the dry side of the hull or wall where they can be serviced. 2 small bolts to attach it to the pot will be plenty. If you can get the sacrificial metal to push flush up against the kettle it would be better yet.

Bear with me, this IS from Wikipedia; but you and they contradict. So if you have a source too that would be awesome. (and probably more reliable)

For this mode of corrosion protection to function there must be simultaneously present an electron pathway between the anode and the metal to be protected (e.g., a wire or direct contact) and an ion pathway between the anode and the metal to be protected (e.g., water or moist soil) to form a closed circuit; thus simply bolting a piece of active metal such as zinc to a less active metal, such as mild steel, in air will not furnish any protection.​
 
Bear with me, this IS from Wikipedia; but you and they contradict. So if you have a source too that would be awesome. (and probably more reliable)

For this mode of corrosion protection to function there must be simultaneously present an electron pathway between the anode and the metal to be protected (e.g., a wire or direct contact) and an ion pathway between the anode and the metal to be protected (e.g., water or moist soil) to form a closed circuit; thus simply bolting a piece of active metal such as zinc to a less active metal, such as mild steel, in air will not furnish any protection.​

nope, you're right. If they borth aren't in contact with the electrolyte there is no electrochemical process. Some bad information I was told a long time ago that stuck with me. Doing a little more research has shown me the error of my ways :) Sorry bout that.
 
So would this work if you had a long strip of magnesium and screwed it to the top of the kettle (above the liquid) with the strip extending down to the bottom of the kettle into the liquid, thus avoiding the necessity of a screw hole which would have to be waterproof if the connection was made under the surface?
 
I am using an Electric Boil Keggle made from a 1 in stainless nut and a 5500W ULD heating element. I'm getting rust on the base of the heating element, and some is transferring over to the stainless steel. Just wanted to get peoples thoughts.

Is this a problem?
Is there a way to avoid this?

Couple of things:

Firstly you have a water heater element. They ain't made for this duty.

Industrial process heaters are sheathed in super alloys like Inconel. Inconel is an austenitic stainless heavy in nickel and chromium.

It's possible your pot is 316 Stainless which is lower in Chrome than 304 and chrome is the only reason that Stainless is stainless. The chrome develops a passive oxide layer on the surface that resists oxidation and corrosion.
Simply put 304 is better for your application. It resists attack better.

But 304 is not the super alloy that Inconel is.
You can get SST to rust by stripping away the passive layer of chrome. Do that with Muriatic acid, various food acids, and of course with regular steel by abrading it against the SST surface. Also you can rust SST by heating it and a high temperature will flash off the chrome and if rust sets in before an new passive layer forms you get rust and pits. Which is why BBQ grill grates made of SST, rust.

You can remove the rust and re-establish that passive chrome oxide layer by soaking your SST in a solution of Citric acid. The solution strength is not terribly important nor is the temperature or time. Heat accelerated the process. You can buy citric acid on E-bay in powder form it is so common. You can even use lemon juice.

Too much time and even citric will take the chrome off, but that takes a very long time.

So you can manage the rust issue by passivating your SST pot with citric acid.

Preventing it is another matter altogether. I suggest you consider a different element. Maybe a Stainless steel CAMCO element. Though that too will eventually fail and start rusting but it won't happen overnight.

As to how this rust is "transferring" I suspect that it's literally falling off the element and the mere contact with iron oxide is attacking your pot.
 
Cliff is damn right. My e-kettle walls got reddish because the rust formed at the base of the element has been dissolved by the wort. I am currently soaking my kettle in about 1 quart of lemon juice bought at Costco's. The rust is dissolving slowly but surely. I will apply a coating of food grade silicone on the base of the element when it is good be shiny!

You can see at the bottom of my kettle that there's two circle which is rust!

xS1oMCU.png
 
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