epcgordy

Recipes 

No leakage into the box - that's key! Rather than the standard gasket that comes with the element, I used a silicone O-ring, which is protected from over tightening by a slighly larger stainless steel washer. When the element is tightened it squeezes the O-ring until the washer contacts the half coupling. This allows the box to be in solid contact with the coupling, and therefore the kettle, for grounding, as well.

SmokingDog

Recipes 

This is what I'm looking at doing (thanks Joshua - "jkfrieke"), except with a dimpled coupling instead of the hex nut:

I like the idea of the silicon o-ring or washer between the outer edge of the coupling and a washer on the element itself though as well.

MrShake

Recipes 

I have to vote for the coupling here, the dimpled coupling provides an AMAZINGLY strong mechanical connection to the vessel. A soldered hex nut relies completely on solder to hold it on.

I'm also curious as to why you guys think the o-ring is necessary. Every element I've purchased came with a sealing washer... the flat surface of the coupling OR hex nut provides plenty of sealing power.

DON'T OVER THINK IT!!

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MrShake - Top Hat Brewery

Project Links: Electric HERMS | Wet Bar

Primary - Air
On Commercial Tap - Sam Adam's Octoberfest
On Tap 2 - Air
On Tap 3 - Air
On Tap 4 - Easy English Mild
On Tap 5 - Air

DustBow

Recipes 

That's what I was thinking, the included gasket was made specifically for the element base. Screwing into a kettle isn't really any different than screwing into a water heater - in theory it should be an "easier" connection because water heaters are under pressure.


Don't you achieve grounding even if the electrical box or washer aren't touching the kettle wall? I was thinking I would ground the incoming ground wire to the electrical box, then the element base is screwed into the soldered fitting which is now part of the kettle itself, right? The solder would conduct electricity to ground the kettle - am I right on this? Even if there is a gasket between the fitting and the element's flat base, the element threads are still in direct contact with the fitting and therefore the kettle.

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"Brewers make wort, yeast make beer."

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aquenne

Recipes 

The issue with the black gasket is some have said it gives off a rubbery flavour. Putting it in a cup of boiling water apparently reveals some of its taste

i just went with silicone for peace of mind. its cheap insurance vs hunting for off flavours in my brew.

epcgordy

Recipes 

There is also the issue of grounding everything. The original black rubber washer alone would prevent the weatherproof box from making solid contact with the coupling or nut. With the washer and O-ring, the O-ring makes a reliable seal, and the washer does double duty - preventing the O-ring from being compressed too tightly, which would allow it to leak; and it provides a positive mechanical connection for a reliable ground as well.

MrShake

Recipes 

I can not imagine that the TINY amount of liquid that would make it past the threads to come into contact with the rubber washer could cause any perceptible off-flavor.

I'd liken it to saying I don't use a maple mash paddle because if I boil a chunk of maple for 4 hours, I can taste maple!! I'll stick with oak.

__________________
MrShake - Top Hat Brewery

Project Links: Electric HERMS | Wet Bar

Primary - Air
On Commercial Tap - Sam Adam's Octoberfest
On Tap 2 - Air
On Tap 3 - Air
On Tap 4 - Easy English Mild
On Tap 5 - Air

epcgordy

Recipes 

Because liquid can follow the threads on the base of the element past the O-ring on the outside, there needs to be a gasket or washer (I used the black one that comes with the element) under the base of the element, inside the box. That, and the gasket or O-ring between the box and the coupling would isolate the box. This would leave only the threads of the element, which can rust or corrode, to make the ground connection between the box and the kettle. By using the stainless washer sandwiched between the outside of the box and the coupler, a solid connection, virtually corrosion-proof, is made between all the parts. No external ground wires, no sealants, no JB-weld required. And, the element can be changed in minutes if necessary.

SmokingDog

Recipes 

It sounds like that most of the couplings that you can purchase are NPT which is a tapered pipe thread; and the heating elements are NPS (straight thread). So fitting isn't exactly dead on. Whereas the hex nut is straight thread.

Although, it definitely seems, after reading and "looking at beer porn", that a coupling set in a dimple would be a stronger fit.

Todd.

kevink

Recipes 

Are you totally against having it welded? That would remove all doubt and let you chose the proper thread type. It really may not end up costing much more and it would be a much nicer installation.