# Kettle Fabrication



## raven19 (7/11/08)

Fellow AHB'ers,

I have just negotiated the services of some stainless steel fabrication in exchange for the structural calculations I provided for a friend.

I am keen to get stuck into AG, and have sourced thus far:
55L Esky
Urn (30L & 20L)

Now just needing a decent sized kettle, as such my basic sketch is attached.





I was thinking keeping it simple as per attached, however I am keen to hear fellow AHB'ers thoughts and ideas.

I will be doing my AG with a friend, hence at least double batches are required.

Q1: Keen to hear thoughts on dimensions (diameter in particular), keeping in mind we shall be probably going with an italian/nasa burner in lieu of immersion heaters. So minimum 50L batches, maybe even triples. Is 500mm diamter too large? Any thoughts on the best diameter for burner efficiency/heat transfer?

Q2: Allowing for some head space, thoughts on 80 - 100L capacity? More or less?

Q3: Thickness of Stainless Steel required. Say 5mm base and 3mm walls? Other suggestions?

Q4: Not being a plumber myself, am I better off just having just the holes drilled, or shall I have stainless steel nuts (or similar) welded to the inside of the holes for ease of fitting valves/taps, etc.

Q5: Is a lid a worthwhile?

Q6: Dimension from tap to floor of the kettle? Minimal to reduce loss? 20mm or more? (Sketch indicatively shows 50mm)

Thats a lot of questions... sorry if overloading...

I am not looking for something bigger than ben hur (just yet :lol: ), however I understand that additional holes for Temperature Probes, chillers, depth guages could be added now.

I have been accumulating photos of relevance from this brilliant site and many great threads, however please feel free to add links/pics to aid in support of your suggestions.

Our setup will be tiered gravity.

Cheers to all, and bring on the weekend...!


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## PJO (7/11/08)

raven19 said:


> Q1: Keen to hear thoughts on dimensions (diameter in particular), keeping in mind we shall be probably going with an italian/nasa burner in lieu of immersion heaters. So minimum 50L batches, maybe even triples. Is 500mm diamter too large? Any thoughts on the best diameter for burner efficiency/heat transfer?
> 
> Q2: Allowing for some head space, thoughts on 80 - 100L capacity? More or less?
> 
> ...




Q1 & Q2: Not sure about heat transfer, but a 500mm diam will only require a height of 500mm to get just under100L. If you want to brew 50L (post boil volume in the kettle) I wouldn't go less than 80L capacity, 100L would be comfortable. (I have a 18gal ≡ 82L kettle and can comforatble do 50L batches even 60L aren't too much of a stretch)

Q3: 5mm base is way too much and the walls do not need to be so thick. It will cost you a packet and way a tonne. I reckon you could get the whole thing made from 1.2mm.

Q4: Depends on how much money you want to spend, but I would get stainless nipples welded in.

Q5: Definitely

Q6: If you whirlpool you could have the tap as low as practically possible.

Q7: Personally I wouldn't add any other holes unless you are going to start using them straight off, but thats just me.

Cheers
PJO


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## jel (7/11/08)

Raven,

You may also have issues relating to using a gas burner on a stainless steel only base. There is a reason the better quality stock pots have sandwich panel bases. Stainless is not the best conducter of heat. You may be able to use a plate of aluminium under the pot to better spread the heat but it wouldnt be my first choice.

I agree with PJO. As this is a kettle, I would be keeping the amount of fitting to a bare minimum. Personally I would only have a single tap connected. I really cant see the point of monitoring the temperature (either its boiling or its not), and its easy enough to use a dipstick to check the volume rather than worry about trying to clean a sight glass etc.

Cheers
J


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## porky (7/11/08)

Mate, 

I use a Keggle and it is 1.6mm thick. I just went and measured it. It is strong enough for sure. 
It will heat up well, but maybe a skirt around the base like a keg would be a good idea?
i use a nasa burner and can get 28 litres boiling in 8 1/2 minutes, which of course starts 
at around 65 plus degrees out of the mash tun.

Cheers,
Bud


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## wessmith (7/11/08)

There is no problem with direct gas heating a stainless base. It is done in commercial breweries and certainly in many HB setups and my 120ltr kettle is set up just like that. The fact s/s is not a great conductor of heat is also not an issue. Sure you will get some hotter spots depending on the flame type (this is why cooking pots have an aluminium base to spread the heat a little better) but the wort will handle that OK. I would however recommend at least 1.6mm material in AISI 304 grade regardless of kettle size. Make sure whoever is welding the kettle up knows it is to be direct heated. This usually requires a double butt weld to be able to handle the thermal stresses.

Re the fittings to be welded in - I would go with at least a 1.0" BSP socket. This will allow you to use the kettle as a mash tun if you ever decide to go the Euro way of brewing and enable the mash grist to be run off to the lauter tun. You can easily bush the 1.0" down to a more practical size for straight kettle usage. My kettle has a 1.0" ball valve which works fine.

Wes



jel said:


> Raven,
> 
> You may also have issues relating to using a gas burner on a stainless steel only base. There is a reason the better quality stock pots have sandwich panel bases. Stainless is not the best conducter of heat. You may be able to use a plate of aluminium under the pot to better spread the heat but it wouldnt be my first choice.
> 
> ...


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## matho (7/11/08)

I have been told that the ideal ratio is 2:3 that is 2 units wide by 3 units high

just my 2c

cheer's
matho


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## Tim (8/11/08)

Dont worry about a kettle - go straight in and hot him up for a conical fermenter!


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## raven19 (17/11/08)

Just an update on progress on the custom kettle.

After numerous hours pondering and researching on kettle make, size, etc., I have gone with a 100L custom 2mm thick kettle. 750mm high, 420mm diameter.

Majority of research was towards either gas or electric. I have decided to go with Electric, as this shall work well with the electric urn and esky mash tun.

Stokes (no affiliation, etc...) have 2400W elements for $65 each, 2 of these for double batches, with my brother in law helping with the wiring and a microcontoller to adjust the temp on one of the elements.

So now its just a matter of confirming hole size in kettle for these 2 elements, plus 1 hole for the tap.

Thanks all for the input thus far on this project. Will be posting pics once we start putting it all together.


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## raven19 (17/11/08)

Tim said:


> Dont worry about a kettle - go straight in and hot him up for a conical fermenter!



Tim - I am thinking this might be the next suggested exchange! I like your thinking!!!! :icon_cheers:


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## mika (17/11/08)

A little more research on the height/diameter ratio may have been a good idea


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## raven19 (17/11/08)

cheers mika, I am planning on mainly double batches - meaning the volume of wort would be around 1:1 for my intended size (50L in 100L pot). SS has been ordered, sure they can adjust... more reading for me now!


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## raven19 (2/1/09)

Update on my stainless steel kettle with photos of course.

2 x 2400kW elements, yet to be wired up, These are ceramic elements with a low heat density, good for the wort I hope!

Just one outlet at the base for the ball valve outlet to gravity drain to the cube.






Ceramic element partially inside sheath



Inside of Kettle

Just a few finishing touches required for wiring, then I am good to go full AG.

:icon_offtopic: Have a double batch of Dr Smurto Golden Ale grain ready to go as my first AG.


Back OT:

More Photos can be found at:
http://www.aussiehomebrewer.com/forum/inde...m&album=400

Cheers and thanks to all for your input thus far...


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## raven19 (2/1/09)

Some more pics of the element & surrounds.



Ceramic element



Metal sheath



Side view of connection plate


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## porky (2/1/09)

raven19 said:


> Update on my stainless steel kettle with photos of course.
> 
> 2 x 2400kW elements, yet to be wired up, These are ceramic elements with a low heat density, good for the wort I hope!
> 
> ...



Now that's what I call brew porn  
You just have to get a stainless brew stand like yardy has for it  
http://brodiescastlebrewing.com/index.php?topic=956.0
A real beauty mate.
What size did you end up with....height and diameter?

Cheers,
Bud


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## scott_penno (2/1/09)

Are you able to provide further details about the elements like where you got them from and how much they cost?

sap.


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## Carbonator (2/1/09)

Has this vessel been leak tested before electricity is applied?

Nice clean design.


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## Bribie G (2/1/09)

I'm no sparky but when I had the 2400 watt 40L urn on the other day and then switched on an electric jug to make a temperature adjustment the circuit breaker tripped so I can only run one at a time. 

Like I say no sparky but since you are using two elements you might want to try out the power point (s) you intend to use.

Lucky man, I'm currently drinking the first pint of my first AG :icon_drool2: and foremost in my mind is "Shyte if only I had brewed a double batch of this" :lol:


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## raven19 (2/1/09)

budwiser said:


> Now that's what I call brew porn
> What size did you end up with....height and diameter?
> 
> Cheers,
> Bud



Bud,

Final dimensions were 415 mm diamter x 760 mm high (internal dimensions), 2mm thick SS metal was used. This was fabricated by a friend in exchange for engineering calculations. He was happy to barter, as am I!!! hehe.

The dimensions above = 102 L, however I lost around 2 L to the element sheaths. Hence capcity is about 100 L, but biggest I dare say we shall do is a triple maybe one day? (Who am I kidding, we shall try to max it out one day I am sure!!!!)

Plan is to do double batches (one for me, one for a mate) for most brews, around 50 L.

Costs to other parts to follow shortly...

I am thinking the stand will have to wait till we buy a house (with shed of course). In the meantime it shall be used on a makeshift stand in my mates shed.

Cheers.


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## Carbonator (2/1/09)

BribieG said:


> Like I say no sparky but since you are using two elements you might want to try out the power point (s) you intend to use.



I'm no Sparky either and it may be against the law for me to advise you to use a Power Outlet, Plug and Wiring no smaller than this;



It may also be against the law for me to advise you to use a CB no smaller than this;



The red hat wearing rat has a good point!


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## raven19 (2/1/09)

sappas said:


> Are you able to provide further details about the elements like where you got them from and how much they cost?
> 
> sap.



Sappas,

No affiliations of course but my costs and suppliers on the kettle to date:

2 x 2400W Elements $66 each from Stokes (Richmond Rd Adelaide)

Stainless steel 2inch tube - free leftover length - thanks Prochem! used for element sheath

Ball Valve $18.70 from Prochem

Hosetail $6 from Prochem

Threaded nipple (welded to kettle for tap) $4 from Prochem

Electrical housing boxes, 2mm thick Stainless steel plate and stainless steel welding and fabrication included in barter.

I still have to source 2 extension leads and grommets, etc to safely wire it up...

I shall be double checking for leaks, etc prior to switching it on for sure!


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## Bribie G (2/1/09)

Carbonator said:


> The red hat wearing rat has a good point!



Possum please, possum (Hat goes off tomorrow)


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## raven19 (2/1/09)

BribieG said:


> I'm no sparky but when I had the 2400 watt 40L urn on the other day and then switched on an electric jug to make a temperature adjustment the circuit breaker tripped so I can only run one at a time.
> 
> Like I say no sparky but since you are using two elements you might want to try out the power point (s) you intend to use.
> 
> Lucky man, I'm currently drinking the first pint of my first AG :icon_drool2: and foremost in my mind is "Shyte if only I had brewed a double batch of this" :lol:



Bribie & Carbonator,

Yes I shall be running this over two different circuits, as the 2400W element = around 10 Amps. Hence will have two different cords, one in shed, and the other running back to the house onto a different circuit, to spread the load!

And fire extinguisher on hand also just in case...

One day in my dream brew shed, I shall have a large dedicated power supply so I can brew big with no issues, until then, I shall tread very carefully with the right input from the right people.

Cheers!


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## raven19 (2/1/09)

sappas said:


> Are you able to provide further details about the elements like where you got them from and how much they cost?
> 
> sap.



Sap, forgot to mention, I did a fair bit of reading up on heating element densities, and the custom internal elements I was quoted were generally well over $200 each, way out of my price range. Hence with the (nearly) free fabrication available to me and the ceramic element option being much cheaper - I figured I am on a winner here...

I am hoping this immediate move to electric AG will be a winning one, with no gas to worry about...


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## Carbonator (2/1/09)

I can see a heat problem in regards to the plastic enclosures.

I'm not sure about those elements, the enclosures may be OK for a while, but I suggest fabricating an SS setup like this;


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## raven19 (2/1/09)

Carbonator said:


> I can see a heat problem in regards to the plastic enclosures.



Fair point indeed.
I shall be watching it like a hawk when we do a water run initially to see on effects just like this.
Thankyou for the reminder!
Will keep all posted on progress...


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## raven19 (23/1/09)

Just another bit of info I gained this arvo from my mate who fabricated the kettle:

Material (Stainless Steel) $370

Hours to fabricate 15 - 20 hrs (I thought this was quite high, then again a fair bit of welding involved...)

I think I have some more engineering calculations to do to pay back this one!

Will be breaking it in this weekend with a 50L batch of Dr Smurto's Golden Ale.


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## afromaiko (9/2/09)

Does anyone know if the electric jug elements mounting hole is the same size as the more powerful 'proper' elements? 

I'm thinking about using a 2400w jug one now and then perhaps upgrading later when I get a 15amp socket run through to the garage.


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## raven19 (9/2/09)

afromaiko said:


> Does anyone know if the electric jug elements mounting hole is the same size as the more powerful 'proper' elements?
> 
> I'm thinking about using a 2400w jug one now and then perhaps upgrading later when I get a 15amp socket run through to the garage.



I have attached a Stokes manual (no affiliation) and some of their 'proper' elements are show with non standard ends, however refer to page 4 - mounting ends. Dimensions shown within.

Hope this of help.

View attachment Stokes_Service_Manual__20Sect_K.pdf


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## afromaiko (9/2/09)

Certainly does, very interesting... Cheers!


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## raven19 (5/5/10)

Digging up my old thread for an update.

Been upgrading the plastic junction boxes on the kettle tonight - picked up some die cast aluminium box's from Jaycar.

The previous wiring and plastic were not quote up to scratch under longer boils - weakened also by accidentally leaving the element on after draining water from the kettle when mashing in a big batch o' beer a while back. Carbonator was right on the money on his previous post.

Piccies to follow tomorrow after the camera is charged.


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## raven19 (15/5/10)

Finally got around to putting the new kettle housings together.

Still have to shorten some wiring, and a bit of fiddling about.

Replaced the old junction boxes with aluminium die cast boxes around $20 from Jaycar (no affiliation).

A test boil resulted in warm aluminium boxes - but not overly hot. Nature of the beast I'm afraid with these elements at 100%.


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## matho (15/5/10)

what is your boil off in that kettle raven?


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## pbrosnan (15/5/10)

It looks like your elements are inside the SS tubing. Doesn't that waste a bit of power? I use a 30L urn as a kettle and like all urns the element is in direct contact with the liquid.


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## raven19 (15/5/10)

matho said:


> what is your boil off in that kettle raven?



About 7 L/hr - I usually have both elements going even for a normal 23L batch for a good rolling boil.


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## raven19 (15/5/10)

pbrosnan said:


> It looks like your elements are inside the SS tubing. Doesn't that waste a bit of power? I use a 30L urn as a kettle and like all urns the element is in direct contact with the liquid.



Yeah these ceramic elements cannot handle liquid contact - hence the SS sheath is required.

I went with these elements due to the heat density benefit and lower cost per element.


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## pbrosnan (15/5/10)

raven19 said:


> Yeah these ceramic elements cannot handle liquid contact - hence the SS sheath is required.
> 
> I went with these elements due to the heat density benefit and lower cost per element.



How long does it take to get a roiling boil going for a given amount of wort?


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## raven19 (15/5/10)

pbrosnan said:


> How long does it take to get a roiling boil going for a given amount of wort?



For a 30L preboil batch for example - around 20 mins - but I usually get the kettle cranking once the wort is up to the element level, then continue to top up the kettle as I continue to sparge.


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## bill_gill85 (16/5/10)

raven19 said:


> Finally got around to putting the new kettle housings together.
> 
> Still have to shorten some wiring, and a bit of fiddling about.
> 
> ...



Raven,

Nice finishing touch with the IEC connectors on the junction boxes. If the warm aluminium boxes are a concern, would it be feasable to insert a silicon gasket (cut from a baking sheet) between the box & mounting flange?

Cheers,

Ben


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## raven19 (16/5/10)

billgill said:


> Nice finishing touch with the IEC connectors on the junction boxes. If the warm aluminium boxes are a concern, would it be feasable to insert a silicon gasket (cut from a baking sheet) between the box & mounting flange?



I did contemplate this - the aluminium boxes appear to be working nicely as a heat sink - the IEC connectors don't seem to get hot at all (they plastic section is rated to 15A also - each element only pulls 10A).

Maybe I will whip one up and do a side by side experiment! I have some left over silicon bakeware in the shed. Cheers!


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## husky (28/8/10)

slightly OT but what heat density would be suitable if you were to use exposed elements as opposed to the sheaths for ceremic elements?
I can see this is where the fabrication time blew out on your kettle as there is a fair bit of work in those.
I recently had a 450x450 2mm s/s kettle fabricated and workshop hours were only 5 or 6 hrs(no handles yet). That was with weld inside and out and a slightly domed base.
Basically im at the stage now of sourcing a couple of elements but prior to reading this thread I had only considered the exposed s/s type elements.


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## raven19 (28/8/10)

Different schools of thought on the heat density - low is preferred to avoid any scorching. But in saying that BIAB Urns have a fairly high heat density with the elements, and I have also used Urns as kettles with no scorching issues.

The main issue seems to be that something custom made for ultra low density will cost a pretty penny!

If there is some space around the element, then surely heat convection would result in a reduced chance of scorching also.


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## Gopha (28/8/10)

Immersion low watt density elements are usually longer in length to spread the heat output over larger surface area.
They are quieter in their operation and in some cases last longer. Low watt density elements are more important when putting together a RIMS type systems (less chance of scorching) and a little less important when doing a full volume boil -Cheers


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