electric heating element rust prevention

[stevehaun]

Seriously, don't you guys have something more important to worry about? Replace the element once a year if it really bothers you. You'll spend more time and money on prevention than you would on replacement.

 

[kezgin]

FAIL

I'm getting discouraged with this since science isn't working, and I'm thinking maybe I'm doing something wrong. Although it did seem a bit better than without the aluminum square. It seems most of the rust is forming where the element penetrates the body of the threaded piece. I guess because the plating isn't as solid there? Could the missing link be exchanging the stainless nut for an aluminum one?

Thanks for the ideas.

Mario

was this a new element or one that you cleaned the rust off of? if there was any rust left maybe it still will spread

 

[passedpawn]

Seriously, don't you guys have something more important to worry about? Replace the element once a year if it really bothers you. You'll spend more time and money on prevention than you would on replacement.

You've wandered into the wrong topic, steve. This is DIY, which is latin for obsessive-compulsive overachievers engaged in spending inordinate amounts of time and cash on making something they could buy down the street.

 

[mariojr]

was this a new element or one that you cleaned the rust off of? if there was any rust left maybe it still will spread

This was a new element and was in water for about 14 hours.

 

[shushikiary]

hmm... this really has my mind jogging... You didnt use any teflon tape on the nut right (shouldnt make a difference, but good to know)? Are we also sure that it's rust and not some other residue left behind from your water?

oh... is that the same SS nut? did the nut perhaps have rust on it from the previous element?

It's also possible the aluminum flashing has a strong oxide layer built up on its surface and that perhaps sanding it moderately before installation would help.

You may simply need to get a better anode material (magnesium fire starter) and/or coat it like lamar says. I feel bad with you spending money on extra heating elements. This must have something to do with your water sense other people use the same element with the aluminum nuts and dont have rust (I fear for your water heater). It could be that the surface area of the aluminum isnt large enough to completely save your mild steel, but that's speculation. Seeing as how it's compressed between the nut and the wall of the keg, assuming you have an electrical connection from the nut to the element (which you most likely do, even with teflon tape), everything seems to have been done right. If I was you, I'd either coat it with POR-15, or try a magnesium fire starter.

I'm starting to understand your frustration mario.... This tells me that I'll be doing both just to be ridiculous. Time to go pick up some POR-15.


conpewter, did you just do a single coat of POR-15, and did you do any of their recommended prep steps (I'm assuming you did it on a new element)? I talked to them on the phone and they said that if I put the recomended 3 layers on that the nut would no longer fit over it, so did you just force the nut on? And when the nut went on did it strip the POR-15 from the threads?

 

[conpewter]

I did the cleaning part (bought their little kit) and then probably put two coats on. I think I brushed on a really light layer once on the threads, but I still had to dig some out when I put the nut on (razorblade) The ones before that I just put it on the face and didn't worry about the threads, I've not seen any rust stains or anything from it, so I think I'll just be Out of Sight Out of Mind on the threads...

 

[mariojr]

Would this be a good choice to try?

http://www.walmart.com/ip/Coghlan-s...00000003260410&ci_src=14110944&ci_sku=8586954

 

[lamarguy]

Would this be a good choice to try?

http://www.walmart.com/ip/Coghlan-s...00000003260410&ci_src=14110944&ci_sku=8586954

Sure, to ignite thermite!

 

[shushikiary]

lol, thermite, I LIKE IT!

In posts from other threads I've read I believe that is what they were referring to, yes. The trick is getting the magnesium part to have a good connection to the SS keg or the steel part of the element.

For your case I'm starting to think that coating it with silicone or POR-15 might just be the better solution... from conpewters experience I think POR-15 would be the be all end all solution. But if you want to try the fire starter I'd love to see the results (dont spend the money if you dont want to, I feel bad having you do experiments at your cost).

I just had another thought.... did you ground your keggle to earth ground? If not, then the cathodic protection may not work properly.

 

[shushikiary]

Well I got the rest of the parts for my keggle, and went out and got some POR-15. That stuff is serious business. I put 2 coats on and let it try, I didnt have to do anything and the nuts still fit just fine. I coated the face plate and the threads. It seems to be working nicely so far.

I did a test boil and let the water sit in it for 5 hours so far, and no issues. I dont have pics of the elements with the POR-15 on them, might grab some later, but here is a video of the thing boiling:

 

[jkarp]

Interestingly, I made a couple heatsticks last weekend using the exact same Camco elements and rust appeared during an overnight soak test between the element and nut. I'm now convinced it's my aluminum kettle that's stopping the rust.

 

[shushikiary]

no rust, POR-15 seems to work well... no anode.

 

[passedpawn]

did you buy the POR-15 online?

 

[shushikiary]

no I got it from a local retailer, I called the POR-15 web site and talked to them about the aplication and if it would be ok, then they directed me to a local retailer so I didnt have to wait a week to get it.

 

[olympionex]

I spoke with an engineer at Camco and found out that their ULWD devices are made with several types of metal. The bushing is made of steel and covered in zinc. The sheath is made of stainless steel. In my case, I'm using a plastic vessel, so these are the only two exposed metals. The stainless will induce galvanic corrosion of the thin zinc layer and rust will quickly occur. Camco's LWD devices have a nickel covering over everything. Theoretically this should help prevent such quick galvanic corrosion.

 

[mariojr]

I spoke with an engineer at Camco and found out that their ULWD devices are made with several types of metal. The bushing is made of steel and covered in zinc. The sheath is made of stainless steel. In my case, I'm using a plastic vessel, so these are the only two exposed metals. The stainless will induce galvanic corrosion of the thin zinc layer and rust will quickly occur. Camco's LWD devices have a nickel covering over everything. Theoretically this should help prevent such quick galvanic corrosion.

Nice work! It's about time someone has come up with some answers around here!

I have just resided to filling up my HLT as needed and not the night before to reduce the rust. In the future when I switch from 120v to 240v I'll be sure to get the LWD elements.

Thanks

Mario

 

[olympionex]

Also, while oxidation of iron is generally caused by oxygen, and not water, this galvanic corrosion can only occur when the two metals are connected by an electrolyte (water, wort, etc). My mistake was to leave water in my HLT for 3 days while testing my new insulation. The problem can probably avoided somewhat by washing and drying everything as soon after the brewing process as possible.

 

[conpewter]

I had the first rust issues with extended time in the water as well, though over time it developed from normal brewing. I will look into the LWD elements for future builds. Looks like Nickel (and nickel alloys) are much much closer to passivated 304 stainless than Zinc (which is wayyyy down the chart)