UK Based - heat sink options - anyone have any successful experiences to share?


 

Petroni North

TVWBB Member
Since ditching the water bowl on my 22½” from the outset in favour of 5kgs of playpit sand, I have had good results albeit with some rapid vent tweaking learning thrown in.

However, I want to find a better/heavier/more effective heat sink with something of greater density and heat holding. I am aiming for something around 30lbs in weight. Research so far has led me to explore

- California Pizza Stone but its too expensive to buy and ship from USA and I cannot find one in Europe
- Terracotta saucers (flower pot stands) but again cannot find the sizes needed yet but I am still trying
- Unglazed tiles (600mm x 600mm cut to rounds) – this is a cheap option but would need two or three stacked to get the mass needed to compete so haven’t cut anything yet (but have a test tile awaiting me in the garage) but I have my doubts about this route
- Sheet steel (6 or 7mm or ¼” or 5/16”) – readily available and any number of people able to cut to size. I have a local forge pricing 480mm and 525mm rounds for me at the moment
- Granite – again, local firm I know has a granite worktop company and is happy to experiment with ¾” or 2cm rounds made from off cuts or breakages but once again still trying to get a handle on how granite might compare to steel/terracotta
I read a really good piece on Serious Eats (Labs) about the effectiveness of steel plate on pizza (good read if you are into pizza) and although this isn’t my application, it did lead me to realise that the conductive nature, dense mass and heat retention/convection qualities of steel might be the way to go, and I am heading that way first

Three questions :

- has anyone experimented with any of the above, or anything else, with any degree of success?
- if the depth of the heat sink object used is ¾”, which it is likely to be, do you put it in the lower area of the water bowl brackets (the bit that measures 480mm across) or in the location of the lower grill which measures 525mm
- if the lower grill space is used; do you then place the lower grill directly on the heat sink and cook on it, or do you put an air spacer between the heat sink and the lower grill and cook on it (to stop the direct conducted heat and aim for radiated/convection instead) or do you just not use the lower grill at all.

I will go ahead with a few dummy runs of my own but if you have anything useful to guide me while I am experimenting I would be keen to share your knowledge and hopefully short circuit the results. Thanks
 
You sayd "any of above" and I must say YES.
Total success 100% perfection garanteed with PIZZASTONE.
Hut You already know it.
 
You sayd "any of above" and I must say YES.
Total success 100% perfection garanteed with PIZZASTONE.
Hut You already know it.

Yes I know you really like your pizza stone #:) but what I am looking for is something in Europe that would be similar instead of having to buy from USA
 
Last edited:
I use a 1/4" steel plate that has a 1" x 1/8" rim. It works well. You can't break it.

PICT0899_zpski72kfcj.jpg


PICT0901_zpstkr43a2h.jpg


PICT0906_zpsrg5ebyua.jpg


PICT0907_zpsm1f1pfy2.jpg


PICT0911_zps2lc8hf7x.jpg


EZ to clean... just toss the old foil & add new. Heat retention is good - moderates temp spikes.

Myself... I wouldn't go much thicker with the metal. It's pretty heavy. This is in an 18.5 WSM
 
Last edited:
That's great Robert thank you very much. I love what you did there. Since posting I have done some research on materials and costs and 1/4" mild steel was the direction I seem to be heading, just waiting on final costs. .

I could use help on one decision which is this; if I am using a 21" WSM and want the best heat sink stabilising effect, my guess is that total mass will play a big part. My thoughts are that by filling the entire space previously occupied by the water pan would be virtually no additional cost (480mm V 525mm) but would increase the mass substantially and therefore, theoretically, the heat sink effect. I see yours (brilliantly photographed by the way) has been reduced in diameter so that it is smaller than the original water bowl size. My thoughts are to literally have a disc cut out of 1/4" (no sides or brackets) and lay it into the area used by the water bowl directly onto the lower brackets.

The second thought was to do the same but instead of cutting it to fit snugly into the water pan brackets, I figured I might go the full width and make it the size of the lower cooking grill increasing the mass to its max for 1/4". The only downsides of that would seem to be getting my fat fingers into the gap between the steel disc and the cooker when it came to removing so I might need to add some sort of handle/s. Either way I can still foil the disc and then add a flattened foiled turkey metal tray on top for easy cleaning/removal to save having to haul the steel out after each cook. Any thoughts on either approach regarding the value of greater mass?

And Hi Enrico (I know you will read this). One question for you. Does your pizza stone fit into the water bowl area or does it sit in the space that the lower grill uses? And if its the grill area, do you have any trouble getting it out without handles?
 
I like Robert's idea but, why not take it one step further and fill the ring with crushed rock or broken terra cotta pot sherds?
Can't be terribly expensive, I completely understand the shipping costs being prohibitive but, your only going to need one, right? Ok, maybe a spare.
 
Let me toss this thought in here. I don't think that metal is the best to use as it is a pretty good thermal conductor, as in it heats fast and gives off the heat fast as well. What you want is more of a thermal capacitor. You want something that will absorb a lot of heat and slowly let it back out. You are looking more for a thermal pressure regulator and storage tank. Stone and masonry are much better at this then metal is. I like Roberts pan, but thinner metal filled with mortar or refractory cement I think would work better.
 
I like Robert's idea but, why not take it one step further and fill the ring with crushed rock or broken terra cotta pot sherds?
Can't be terribly expensive, I completely understand the shipping costs being prohibitive but, your only going to need one, right? Ok, maybe a spare.

I am looking at setting up 4 WSMs 57s split between 2 sites (about 5-6 miles apart) so I want to find something I can replicate inexpensively. If I can find something that works I will probably also either share the info with other UK based 'cookers' or set up a tiny supply business to help others avoid the one off time/effort/cost that goes with this learning curve. As far as the terracotta sherds go, seems too simple to be true and I could simply lay them in the existing water bowl instead of the current sand. It would also be dead easy to play with different 'mass' amounts. Though I am regretting having taken a large piule of broken terracotta flower pots to the dump last September lol. Good call Timothy

Let me toss this thought in here. I don't think that metal is the best to use as it is a pretty good thermal conductor, as in it heats fast and gives off the heat fast as well. What you want is more of a thermal capacitor. You want something that will absorb a lot of heat and slowly let it back out. You are looking more for a thermal pressure regulator and storage tank. Stone and masonry are much better at this then metal is. I like Roberts pan, but thinner metal filled with mortar or refractory cement I think would work better.

Thanks Andrew. I am no expert (obviously) but what little research I have done shows that steel and granite both act as great conductors and as it is uniform heat I am aiming for, I sort of thought that as it takes a fair time to get the object (whichever is used) up to initial heat, once there, its stored heat would be evenly released once the approximate temp level had been reached. So if the lid had to come off for any reason, or door opened etc, the ability to restore the desired temp should be restored fast. I haven't researched stone or crushed rock (other then learning that firebricks were an insulator rather than a heat store) so I am still unsure how to compare your ideas with those I have studied so far. But I shall start the research right now, many thanks for your advice. I suspect that lava rock might be a cheap and flexible material to try still using the same water bowl as a holder but I suspect much of the heat will simply flow around where with a flat plate of steel/granite is might be more likely to be absorbed. Interesting brain food this
 
I'm another steel plate user, it's not as fancy as Robert R's it's just a 10ga steel disk foiled that sits down inside the bowl a couple of inches, I didn't want something to absorb heat just deflect the direct heat, being it sits inside the bowl it does create a nice air pocket between the bottom of the bowl and the disk, temp control is very easy and stable, I like it myself.

I now only use the larger disk since I made this post
http://tvwbb.com/showthread.php?31517-The-water-pan-quest-is-over-finally-NOW-with-PICs
 
Last edited:
I'm another steel plate user, it's not as fancy as Robert R's it's just a 10ga steel disk foiled that sits down inside the bowl a couple of inches, I didn't want something to absorb heat just deflect the direct heat, being it sits inside the bowl it does create a nice air pocket between the bottom of the bowl and the disk, temp control is very easy and stable, I like it myself.

I now only use the larger disk since I made this post
http://tvwbb.com/showthread.php?31517-The-water-pan-quest-is-over-finally-NOW-with-PICs

Thanks Don. I was aiming to experiment with two plates, the narrow one sitting in the water bath recess and the larger one in the lower grill space each being 25lbs and 30lbs approx respectively and a dozen chicken thighs on the top grill to see what happens. But after seeing yours, I could get the smaller disc cut a few millimetres smaller so that it could sit into the lip of the water bowl and add that as a 'buffer' option to the experiments.

I propose setting up just 16 briquettes on each test, in a grid 4x4 with the 4 in the centre being lit and the outer ring unlit, then open all vents and temp check every 5 minutes until they are burned out. Not rocket science I know but the results should give me something to think about. All I need first is a door that doesn't resemble a piece of corrugated iron as currently even reshaping and using high temp mastic bead I still have heat/smoke pouring out of my cooker so I'll hold the tests until either the replacement fixes things or I buy a CB door.
 
I just took a piece of tin foil large enough to cover the door back when folded in half and put the door back on then tucked what little that stuck out back in around the edge, works pretty good. The 2 plates did work but when I found out 1 works just as well and the plates really doesn't weigh that much, heck when I used a 3/4 bowl of sand it weighed a whole lot more, I come up to temp fast, use less fuel and as already stated easy to control, give you one example of how good, I watched the first 2 Lord of the Rings movies back to back and only adjusted the vents 1 time, well the 1 vent on the bottom I was using anyway. Oh and by the way, with the 1 disk only my bowl weighs maybe 1.5 lbs more than the bowl
 
I could use help on one decision which is this; if I am using a 21" WSM and want the best heat sink stabilising effect, my guess is that total mass will play a big part. My thoughts are that by filling the entire space previously occupied by the water pan would be virtually no additional cost (480mm V 525mm) but would increase the mass substantially and therefore, theoretically, the heat sink effect. I see yours (brilliantly photographed by the way) has been reduced in diameter so that it is smaller than the original water bowl size. My thoughts are to literally have a disc cut out of 1/4" (no sides or brackets) and lay it into the area used by the water bowl directly onto the lower brackets.

I think that would work. I found the disc at a local metal supply & the price was right so that's what I used. The reason for the rim: make a dish with foil when smoking butts, chickens & other greasy stuff.

The second thought was to do the same but instead of cutting it to fit snugly into the water pan brackets, I figured I might go the full width and make it the size of the lower cooking grill increasing the mass to its max for 1/4". The only downsides of that would seem to be getting my fat fingers into the gap between the steel disc and the cooker when it came to removing so I might need to add some sort of handle/s. Either way I can still foil the disc and then add a flattened foiled turkey metal tray on top for easy cleaning/removal to save having to haul the steel out after each cook. Any thoughts on either approach regarding the value of greater mass?

I suspect that would severely restrict air flow.

Let us know what you do & how it works for you.
 
Last edited:
Pet.

A half inch granite slab placed on the water pan tabs will do it. And a round disposable foil cake pan to catch any drippings.
 
Last edited:
Pet.

A half inch granite slab placed on the water pan tabs will do it. And a round disposable foil cake pan to catch any drippings.

Thanks Tony. I have been quoted £60 for a 2cm thick 480mm diameter granite round and £48 for the steel plate same size, with one more quote for steel still to come back. Charlie at BattleBoxBBQ said B&Q do a ceramic plate that fits into the tray at a cost of £12 (but damned if I can find it there). He says he and lots of the competition cooks use it but I am driving down to pick up a Cajun Bandit door tomorrow (ooh its 2am, so today) so hopefully I'll track it down during the chat. If the tests I eventually do produce anything worth sharing I'll follow up.
 
Thanks Tony. I have been quoted £60 for a 2cm thick 480mm diameter granite round and £48 for the steel plate same size, with one more quote for steel still to come back. Charlie at BattleBoxBBQ said B&Q do a ceramic plate that fits into the tray at a cost of £12 (but damned if I can find it there). He says he and lots of the competition cooks use it but I am driving down to pick up a Cajun Bandit door tomorrow (ooh its 2am, so today) so hopefully I'll track it down during the chat. If the tests I eventually do produce anything worth sharing I'll follow up.

If you could let me know what you find out about the ceramic plate at B&Q please, I would be rather interested. Because I think I might have found one up the road from you at Longacres. Just not had the time to get there to pick one up.
 
Petroni (is that your first name? last name? nick name?), I've got the perfect solution for you. Over here, clay saucers in the size I use (for 18" WSM) work perfectly and is cheap. For your 22", it[ seems to not be available at a price you are comfortable with..

MAKE YOUR OWN clay saucer :) I see you can buy plastic saucers in the size you need (amazon uk) so if you're not sure you would do a good free-style job, buy the plastic one to use as a form/template.

Here is a UK based website whose members are dedicated to making clay fired ovens using clay powder or clay they dig out of the ground. Certainly is a cheap way to get what you need and best of all, exactly what you need.

http://ukwoodfiredovenforum.proboards.com/thread/841/clay-mix
 
If you could let me know what you find out about the ceramic plate at B&Q please, I would be rather interested. Because I think I might have found one up the road from you at Longacres. Just not had the time to get there to pick one up.
No joy at B&Q so far and alas as it was Frdiay I decidfed not to fight the Friday rush hour traffic driving back from Brighton and got BattleBoxBQQ to FedEx it to me instead so I didn't have the chat about the ceramic plate. The following post might supercede that and if so, I'll update this.

Petroni (is that your first name? last name? nick name?), I've got the perfect solution for you. Over here, clay saucers in the size I use (for 18" WSM) work perfectly and is cheap. For your 22", it[ seems to not be available at a price you are comfortable with.

MAKE YOUR OWN clay saucer :) I see you can buy plastic saucers in the size you need (amazon uk) so if you're not sure you would do a good free-style job, buy the plastic one to use as a form/template.

Here is a UK based website whose members are dedicated to making clay fired ovens using clay powder or clay they dig out of the ground. Certainly is a cheap way to get what you need and best of all, exactly what you need.

http://ukwoodfiredovenforum.proboards.com/thread/841/clay-mix

Long story short. In about 1988 I was playing an old style video game called Dig Dug at Aberdeen Dyce Airport in Scotland but I was a little drunk at the time and when I somehow managed to get in the top ten high scores I managed to mistype my name as Petroni instead of Peter N. In later life I was required to setup up a web site linked to some political stuff I was involved with and I started getting some very odd messages including stuff like "he has really let himself go" etc. If you look up PeterNorth.com you will learn why!. I scrapped my website and started using my drunken typo in real life and also in my MMORPG game play.

Finally, I love the home made plastic pot fashioned saucer idea. I'll get on to it right away. Meanwhile I managed to get a mild steel disc made (being made) for £40 which weighs in at 23lbs approx and hope to start some test cooks early next week with the new door and stabilising plate. If I learn anything worth sharing I'll post it

Edit : Just read that clay is a poor conductor/great insulator which seems to be the exact opposite of what I need (or is it), I am starting to forget why I was draining the swamp.....
 
Last edited:
Edit : Just read that clay is a poor conductor/great insulator which seems to be the exact opposite of what I need (or is it), I am starting to forget why I was draining the swamp.....

It's meant to act as a heat sink (instead of water) in the bowl as it's a lot lot lot less messy to deal with than a grease-laden bowl of water that you need to dispose of when finished.

At the low temps we smoke at, it can absorb/moderate the heat generated without releasing it quickly which would cause heat "spikes".

If doing high heat cooks, you wouldn't use anything at all (other than a foil-lined empty bowl to deflect the heat to the sides, thereby providing some protection from direct heat beating on your subject. The saucer can only absorb so much heat before it starts off-loading it. Again, not an issue at our usual smoking temps.

Also, you put the saucer in at the start (ie: low temperature environment) so it heats up at the same rate/time as the coals. Put it in after the coals are at temp and you risk cracking the saucer.

In an aside, I use a 12"x24" baking stone in my stove for baking bagels. I leave it in there for any other oven-based cooking as well because it absorbs heat (same as the saucer in the WSM). The beauty of that is when I have to open the oven door for any reason, I release a lot of heated air (unintentionally). By having that heated stone in there, the stove doesn't take nearly as long to get back to the desired temps.

The same principle works with the saucer/water. Lifting the smoker lid lets a lot of heat out/takes a while to rise because now you've got all that cold air in there. The water does the same heat-retention trick but as I said, is a lot messier when it comes to disposal time.
 
Last edited:

 

Back
Top