Silcone sealant for elements

I had major rust problems on the face and threads of my kettle elements and was wondering if something like this would work to seal them?

I bought a cheapo magnesium fire starter that I'd have to remove the flint/glue part on and cut in half to split for the kettles and was just exploring the options before I do that. I have the 5500W ripp ulwd elements btw.

Probably but why not just buy a gasket for your element?

The threads and face are still inside the kettle where they are subject to galvanic corrosion so I guess I'm not sure what you're suggesting? I was talking about coating the parts exposed to that process inside the kettle.

OH!! I thought you were saying it was rusting out around your threads and leaking. I don't know about coating stuff. The sealant may impart off flavours and even though it is food grade does not mean it is safe to be potentially ingested.

Food grade doesn't always mean it should be immersed into a pot of boiling wort. It seems to have more chemicals than just a pure silicone sealant. I'd be more inclined to use the sacrificial anode method.

I was kind of wondering about that too. You see people here recommend silcone but none of them are rated for the job that I know of. Unless I hear otherwise I may just hack this magnesium firestarter up and throw it in the pots and see what happens.

What do you mean chemicals other than silicone?

I used this.

And what do you mean none of them are rated for the job? The one linked is the basic general purpose translucent silicone sealant, food safe, and good to 400F.

I smeared it over the face of the element, making sure everything was covered, let it cure completely, and did a quick boil and oxiclean soak to get rid of any possible residues before using it in the boil. It's been holding up well so far.

Personally I trust silicone at boiling temps much more than cooler plastic at mash temps.

I'm not a chemist by any means. However I don't think you can compare the process of air dry curing of a Silicone Sealant to that of Silicone High Temp Tubing for example. As far as I know the sealants are meant to be used for incidental contact, not continuous submersion in a food product. I could be wrong, I'd love to see the evidence that says it's fine, as I'd like to use some on my set up.

from McMaster catalog page you linked to:
These silicones (formerly GE silicones) form a tough, rubbery solid in 24 hours at room temperature. Not for underwater, concrete, or mortar applications. These products are VOC compliant in all 50 states as of October 1, 2008.

I looked into the "not for underwater" disclaimer before I decided to use the silicone. I don't remember exactly, but it didn't always have the disclaimer; I think it is either referring to using it as an adhesive rather than just a sealant or actually applying it underwater.

It's used in aquariums, despite that disclaimer. Just search for discussions of RTV-108 use for those purposes.
http://www.fyurl.com/rr.php?c=2&site=www.homebrewtalk.com&url=http://www.alda.com.tr/eng/sss.asp#7
"The warning on our containers is in regards to some hydrolytic stability testing we've done with our adhesives in the past. Technically, RTV silicones start to lose some of their physical elastomeric properties with prolonged submersion in water (specifically tensile strength and elongation percentage). As RTV108 and other materials like it are designed for industrial use, we place that warning to allow end users to know that it may not make a good choice for a long term load bearing adhesive underwater. That being said, small sized aquarium manufacturers have used this material for quite some time without issue, as their use is quite different and on a much smaller scale from what we had in mind when the warning was placed on the package."

You can get 1/4 in thread in mag rods off amazon. They are designed for rv water heaters.