Induction hob and old brass pan

[Stephen Mawson]

I have an old and heavy (8 kilos empty) brass pan that I use for jam-making.
It is ideal for the purpose, the thick brass bottom preventing any burning
or sticking while boiling jam and it is big enough to make 20 pounds of jam
at a single boiling. I have used it successfully with a gas hob and latterly
with a ceramic electric hob; but of course now that we have a new induction
hob I have to think again. I don't want to give up the brass pan if at all
possible.
I have bought one of those flat induction-hob-suitable adaptors which go
between the induction hob and a non-induction-type pan, of a size to suit
the bottom of the brass pan. I have taken a hammer to the bottom of the pan
to make it as flat as possible -- it's now within a millimeter or two all
over. It works, but the adaptor gets hotter than I think is safe for the
surface of the hob, certainly well over 100 degrees C. The problem, of
course, is poor thermal contact between the flat adaptor and the
not-quite-flat pan.
I hesitate to grind the pan flat because, thick though the bottom is I might
end up with a hole. And I doubt if it is practicable to braze or solder a
thick flat copper sheet to the pan because it would need to be in
metal-to-metal contact all over to achieve anything
So does anyone have a solution please? Many thanks in advance.

Stephen

[polygonum]

How about getting a gas (or even electric) single burner and using that?

When we got an induction hob I looked round at those iron plates but got
a generally poor impression of them in use.

What about a mercury double-boiler? Iron/steel pan, slosh a bit of
mercury in, then put the maslin on top but in contact with the mercury?
Keep gold rings away.

--
Rod

[Owain]

On Mar 15, 12:58 pm, "Stephen Mawson" ... wrote:
> I have an old and heavy (8 kilos empty) brass pan that I use for jam-making.

> So does anyone have a solution please? Many thanks in advance.

Borrow a neighbour's hob in exchange for some jam?

Use the small individual gas burner(s) for camping?

Hire a tar boiler gas burner (if you're in Chelsea, they're called
paella rings)

Owain

[Andrew Mawson]

"Stephen Mawson" wrote in message
news:MfCdnZ2WmfBuh97M...@bt.com...

If the 'adaptor plate' is still in reasonable fettle I can silver solder or
braze it to the bottom of the brass pan if you like. My 60 ton press will
sort out the flatness issues! Probably have to drill a few holes in the
adaptor plate to get enough braze penetration but it'll work I'm sure. (Soft
solder would be unsafe as it would be very weak at jam temperatures)

Andrew

[GB]

On 15/03/2013 12:58, Stephen Mawson wrote:

I think that you have been very cunning in creating a problem that need
not exist at all, and I suspect doesn't! I have a solution.

Make a horizontal turntable, and temporarily Araldite the pan to it.
Then spin the pan rapidly in one direction. Once the contents start to
get up to speed with the pan, reverse the direction.

As you may need to use very high speeds that may test the physical
integrity of the pan, I recommend a suitable burst-proof containment system.

In addition, the spin speed, or at least the angular acceleration may
need to be adjusted to take account of the different viscosity and
hysteresis in the jam as it starts to thicken and set.

Continue to do this until the jam is cooked or the copper pan melts,
and/or both.

Please report back.

[dennis@home]

Couldn't you drill the holes, chamfer them so they are bigger at the
bottom and then press the plate into the brass pan so that some of the
brass flows into the holes and secures the base?
That's how the induction bases are held on my aluminium pans.

[Roger Mills]

On 15/03/2013 12:58, Stephen Mawson wrote:

How about using some conductive paste - of the type used on computer
processor heat exchangers - between pan and adapter ring? That stuff can
stand fairly high temperatures - but you'd have to check the spec to be
sure.
--
Cheers,
Roger
____________
Please reply to Newsgroup. Whilst email address is valid, it is seldom
checked.

[Toby]

On 15/03/2013 12:58, Stephen Mawson wrote:

I do realise you have said you want to keep the current pan, but a
replacement induction friendly one is around £23 delivered.
http://www.ebay.co.uk/itm/360591135149
I cant see you will get even heat transfer by attaching something to the
bottom of the current pan without some serious work...

Does your induction hob have a constant setting - on my (Siemens) one,
you can get the pan to whatever temperature you like, then press the
temperature up and down buttons together so it shows -C- the hob then
monitors the temperature of the pan and keeps it constant, which should
help...

The only solution I can see that will work reliably is this, or a
separate gas or electric burner.
http://www.ebay.co.uk/itm/121078153504 - electric
http://www.ebay.co.uk/itm/321089145818 - Gas
http://www.ebay.co.uk/itm/200765255994 - Gas


--
Toby...
Remove pants to reply

[polygonum]

If you shove an adaptor on, how will the hob know the temperature of the
pan? It will know the temperature of the adaptor. With a highly variable
thermal connection between that and the pan, it is not going to work, IMHO.

--
Rod

[F Murtz]

It is not brass, waste of an URL as he would know of the modern
alternatives He was talking about brass pots.
As an aside does anyone know of any medical problems of brass
constituents leeching into jam?

[Brian Gaff]

Lots of that gunge you put on heatsinks for pc processors?

Brian

--
From the Sofa of Brian Gaff Reply address is active
"Stephen Mawson" <stephenj...@btopenworld.com> wrote in message
news:MfCdnZ2WmfBuh97M...@bt.com...

[polygonum]

On 16/03/2013 03:02, F Murtz wrote:
<>
> As an aside does anyone know of any medical problems of brass
> constituents leeching into jam?
<>

For my self, I know nothing. But this link has some discussion:

http://www.bushcraftuk.com/forum/showthread.php?t=26884

I have always understood that untinned copper and brass are OK for jam
but not chutney and pickles. And even then, not leaving the fruit in the
pan longer than necessary. I guess so long as we don't get more than 900
micrograms of copper a day...

--
Rod

[Stephen Mawson]

Very many thanks to all who made suggestions, facetious or serious. I've
come to the sad conclusion that I shall probably have to give up the old
brass pan and buy a new induction-suitable one. The other real alternative
was a stand-alone electric boiling ring but they seem to come 18cm in
diameter and 1500 watts and for a fast boil the large brass pan needs more
than that in both respects.

Turning to the health aspect that someone raised, I doubt whether the copper
and zinc in the brass would do much harm, though I have noticed that the pan
is beautifully shiny inside after I've been making slightly acid marmalade.
More concerning is that the old brass (late nineteenth century, I think) may
well have more lead in it than would be approved of nowadays; perhaps I
should have tinned it inside.

Many thanks again,

Stephen

[polygonum]

But would that tinning have arsenic in it? :-)

I meant to mention marmalade as questionable even if most fruit (I
suspect I mean non-citrus) is OK.

--
Rod

[Andy Champ]

On 16/03/2013 16:57, Stephen Mawson wrote:

> perhaps I
> should have tinned it inside.

With what? Leaded solder?

Andy

[Stephen Mawson]

"Andy Champ" <no....@nospam.invalid> wrote in message
news:tOKdnXaouYI-dNnM...@eclipse.net.uk...

No, tin: that is what was (and is) used, in "tin" cans for example, to keep
foodstuffs away from other metals.

Stephen

[Sam Plusnet]

In article <aqgkm0...@mid.individual.net>, rmoud...@vrod.co.uk
says...

>

>
> What about a mercury double-boiler? Iron/steel pan, slosh a bit of
> mercury in, then put the maslin on top but in contact with the mercury?
> Keep gold rings away.

After you.

Do remember to inhale and breath in all that wonderful mercury goodness.

--
Sam

[Grimly Curmudgeon]

On Sat, 16 Mar 2013 16:57:48 -0000, "Stephen Mawson"
<stephenj...@btopenworld.com> wrote:

>Very many thanks to all who made suggestions, facetious or serious. I've
>come to the sad conclusion that I shall probably have to give up the old
>brass pan and buy a new induction-suitable one.

Some grades of stainless steel are magnetic - cut a disc of that, lay
it in the bottom of the pan.
Try it with a sample piece first to save hassle.

[pmai...@googlemail.com]

The problem is induction hobs are too low power - the brass pan would work in an induction furnace :) Putting anything in the brass pan won't get detected by the hob as there's too much brass in the way which is too conductive for the hob.

How about going to Pyrex and the microwave?

[Gee ain't this much easier than diybanter.com!]

[Andy Burns]

pmai...@googlemail.com wrote:

> [Gee ain't this much easier than diybanter.com!]

You might find it even easier if you moved to usenet proper, not google
groups ...

http://wiki.diyfaq.org.uk/index.php?title=Newsgroup_access_tips

[pmai...@googlemail.com]

What's with the lack of edit feature on that wiki ?

News: reader - hmmm, hang on a mo...

[Andy Burns]

I think accounts are granted more or less on request

[The Natural Philosopher]

According to wiki you buy a steel disk and stick it on top and the pan
on that.

BUT I think the wiki article is written by someone with very little
electrical knowledge.

Seems to confuse skin effect with resistance, which is anyway irrelevant
at this level of frequency, and mistake the reason for using fibre would
wire instead of single for enamelled. Basically flexibility and heat.

Also this is an induction hob, and eddy currents are not really the
point. Its pure resistive heating. Steel or ferromagnetic material is
only useful in that it concentrates the flux more, but brass will still
heat in an AC field from pure - guess what - INDUCTION.


--
Ineptocracy

(in-ep-toc’-ra-cy) – a system of government where the least capable to
lead are elected by the least capable of producing, and where the
members of society least likely to sustain themselves or succeed, are
rewarded with goods and services paid for by the confiscated wealth of a
diminishing number of producers.

[polygonum]

I am not convinced that brass will work - even if only because the
control mechanism won't let it - maybe simply by mis-detecting what is
there.

--
Rod

[pmai...@googlemail.com]

Induction works with any metals. I believe the domestic induction hob has sensory electronics to avoid overload - and this is why they quit working with brass, copper, Alu etc. The idea of inducing currents in ferromagnetics seems logical in that the induced electrical current in the base of the pan generates an alternating magnetic field within the pan and these currents significantly help the heating rather than the pure electric load.

Think of the hob as a transformer - many turns in the primary coil in the hob and one turn in the pan - therefore an induced very high current and v. low voltage in the pan. The high current generating heat and in the ferromagnetics generating heat from magnetic eddy currents.

As I believe 'metal' derives from a material's ability to conduct electricity, any metal will work with an induction source to produce heat - but not all induction sources will work with any metal - due to protective overload circuitry.

[The Natural Philosopher]

then slap an iron slab on top

[Fred]

On Sat, 16 Mar 2013 08:58:02 +0000, polygonum <rmoud...@vrod.co.uk>
wrote:

>For my self, I know nothing

Me neither ;)

I was thinking of having an induction hob when we complete the kitchen
refurb. We would need some new saucepans to be compatible with this
and besides, the ones we have are on their last legs anyway.

I didn't know anything about saucepans, so I read here:
http://www.johnlewis.com/buying-guides/cookware-buying-guide

I thought iron would be best but the link suggests that because there
is so much mass to iron pans, they take longer to heat up and continue
to hold heat even after the hob is turned off. It also advises about
the weight of the pans when full. So all of these have put me off iron
pans.

I was surprised that the web site claims steel does not conduct heat
very well, I thought all metals did. Surely steel pans must conduct
better than glass ones?

The web site mentions copper, but I haven't seen any 100% copper pans
(and of course they would not work with induction). Pans sold as
"copper" seem to have an outside copper layer and then inside layers
of steel or aluminium, which is very misleading imho.

So I guess I will end up with some aluminium ones that I presume have
a steel base. I would have thought aluminium leaching would be more of
a health concern that copper leaching but I think the anodising
prevents that.

[polygonum]

I think our are all stainless in various makes and forms. Oh - maybe a
frying pan or two are aluminum with a suitable steel bit in the base.
Have no problem with speed of heating up.

Have in the past used iron - yes heavy, yes retains heat. I like frying
on iron, got an enamelled iron casserole, but wouldn't choose it for
much else.

--
Rod

[Clive George]

On 20/03/2013 18:44, Fred wrote:

> I thought iron would be best but the link suggests that because there
> is so much mass to iron pans, they take longer to heat up and continue
> to hold heat even after the hob is turned off. It also advises about
> the weight of the pans when full. So all of these have put me off iron
> pans.

The thermal inertia and general mass makes them really good for some
things (eg simmering), so it's worth considering getting one or two.

> I was surprised that the web site claims steel does not conduct heat
> very well, I thought all metals did. Surely steel pans must conduct
> better than glass ones?

Stainless steel doesn't conduct heat as well as eg copper or Al. Hence
stainless drinks flasks.

Decent stainless pans have an Al or Cu base which makes them work rather
better. I'd go for these - they work well and can take abuse.

[polygonum]

I thought that stainless was used for flasks because it offered a
combination of strength despite thinness plus safety and gas-tightness
which would not be possible with copper or aluminium.

--
Rod

[Clive George]

On 20/03/2013 19:37, polygonum wrote:

>> Stainless steel doesn't conduct heat as well as eg copper or Al. Hence
>> stainless drinks flasks.
>>

> I thought that stainless was used for flasks because it offered a
> combination of strength despite thinness plus safety and gas-tightness
> which would not be possible with copper or aluminium.

If you made a drinks flask out of copper or Al you'd end up with cold
tea very quickly :-)

http://en.wikipedia.org/wiki/List_of_thermal_conductivities

Look at the numbers for the various materials. Stainless doesn't conduct
that well for a metal.

The strength is another good reason to use it, but you wouldn't use a
material with the strength of stainless and the conductivity of copper.

[polygonum]

It is not a matter of thermal conductivity - there is a vacuum - which
is why they are vacuum flasks. The only bit that really matters
thermal-conductivity-wise is the small bit around the neck.

--
Rod

[Dave Liquorice]

On Wed, 20 Mar 2013 18:55:43 +0000, polygonum wrote:

>> I thought iron would be best but the link suggests that because there
>> is so much mass to iron pans, they take longer to heat up and continue
>> to hold heat even after the hob is turned off. It also advises about
>> the weight of the pans when full. So all of these have put me off iron
>> pans.

Cast iron presumably, like Le Cruset? They are heavy and do hold heat not
a problem on gas or induction but on hot plate electric would be a
nightmare.

>> The web site mentions copper, but I haven't seen any 100% copper pans
>> (and of course they would not work with induction). Pans sold as
>> "copper" seem to have an outside copper layer and then inside layers
>> of steel or aluminium, which is very misleading imho.

Copper used to be used, look in the kitchens of victorian country houses.
The inside was tinned, (with tin, not solder,,,) though not bare copper.
The scullary maid would have to keep the outsides polished.

>> So I guess I will end up with some aluminium ones that I presume have
>> a steel base. I would have thought aluminium leaching would be more of
>> a health concern that copper leaching but I think the anodising
>> prevents that.

Not seen ali pans that are anodised normally bare ali. I don't like
coatings on pans, it wears off.

> I think our are all stainless in various makes and forms. Oh - maybe a
> frying pan or two are aluminum with a suitable steel bit in the base.
> Have no problem with speed of heating up.

The ones we have here that are induction hob suitable are stainless steel
with a fairly thick base that presumably has a lump of iron in it.
Respond very quickly to changes in heat setting, not quite as quick as
gas but not far off it. Meyer Bella Classico these are quite old, >10
years, and the current range of the same name on the web doesn't mention
induction. Maybe they have changed the construction of the pan base?

--
Cheers
Dave.

[Alexander Lamaison]

"Dave Liquorice" <allsortsn...@howhill.com> writes:

> On Wed, 20 Mar 2013 18:55:43 +0000, polygonum wrote:
>
>>> I thought iron would be best but the link suggests that because there
>>> is so much mass to iron pans, they take longer to heat up and continue
>>> to hold heat even after the hob is turned off. It also advises about
>>> the weight of the pans when full. So all of these have put me off iron
>>> pans.
>
> Cast iron presumably, like Le Cruset? They are heavy and do hold heat not
> a problem on gas or induction but on hot plate electric would be a
> nightmare.

What makes 'hot plate electric' different for cast iron? And do you
mean a solid metal hob or a flat ceramic one? Asking cos I'm thinking
of buying the latter.

Alex

--
Swish - Easy SFTP for Windows Explorer (http://www.swish-sftp.org)

[polygonum]

There have been quite a few shattered ceramic hobs caused by careless
use of cast iron pans.

--
Rod

[Andy Champ]

On 20/03/2013 18:44, Fred wrote:

> I was thinking of having an induction hob when we complete the kitchen
> refurb. We would need some new saucepans to be compatible with this
> and besides, the ones we have are on their last legs anyway.

Just done exactly that. Had to buy new pans - got a set of stainless
ones which were a special deal in Debenhams.

Inductions hobs are the dogs wotsits. Far FAR faster than gas, which is
the fastest thing I'd ever used before.

I've just gone and checked - it will go from cold to boiling half a pint
of water in under a minute.

On the other hand, they are useless for woks...

Andy

[polygonum]

There are special induction rings for special woks...

http://beautifulkitchensblog.co.uk/2011/10/06/wok-cooking-using-an-induction-hob/

(I didn't even bother to think about the cost...)

--
Rod

[The Natural Philosopher]

On 20/03/13 19:57, polygonum wrote:

>
> It is not a matter of thermal conductivity - there is a vacuum - which
> is why they are vacuum flasks. The only bit that really matters
> thermal-conductivity-wise is the small bit around the neck.
>

+1

[The Natural Philosopher]

one here. No, not me. A previous GF/s thick brother

[Alexander Lamaison]

Is it just a case of impact, or is it a thermal issue too? SWMBO is
careful the the point of obsession so, if it's the former, she should be
fine.

[The Natural Philosopher]

impact.

>
> Alex

[Dave Liquorice]

On Wed, 20 Mar 2013 20:49:26 +0000, polygonum wrote:

>> On the other hand, they are useless for woks...
>

> There are special induction rings for special woks...

Bet they don't thump out the 5kW+ (for small one) that a proper gas wok
burner does...

Forced air charcoal is (was...) the normal source of heat for a wok in
China. Serious heat...

--
Cheers
Dave.

[polygonum]

And a knee controller on the gas ones, at least.

No - some are 3kW.

--
Rod

[dennis@home]

On 20/03/2013 21:34, Dave Liquorice wrote:

> On Wed, 20 Mar 2013 20:49:26 +0000, polygonum wrote:
>
>>> On the other hand, they are useless for woks...
>>
>> There are special induction rings for special woks...
>
> Bet they don't thump out the 5kW+ (for small one) that a proper gas wok
> burner does...

They may give out 5kW but a lot of it goes up the sides and out the
extractor.

[Dave Liquorice]

On Wed, 20 Mar 2013 21:54:16 +0000, polygonum wrote:

> And a knee controller on the gas ones, at least.
>
> No - some are 3kW.

They vary greatly, a google about found (commercial) gas wok burners with
up to 60,000 btu output, that's 17 kW or there abouts. I agree that a
domestic one isn't going to be much more tha 5 kW if that.

--
Cheers
Dave.

[polygonum]

Sorry - think I confused in my previous - the domestic induction one I
found a spec. for was 3kW. Yep - have seen figures in the 15-17 range
for gas wok burners. That is a lot of heat going into a few bean
sprouts. :-)

--
Rod

[Dave Liquorice]

On Wed, 20 Mar 2013 20:02:39 +0000, Alexander Lamaison wrote:

>> Cast iron presumably, like Le Cruset? They are heavy and do hold heat
>> not a problem on gas or induction but on hot plate electric would be a
>> nightmare.
>
> What makes 'hot plate electric' different for cast iron? And do you
> mean a solid metal hob or a flat ceramic one?

Solid metal ones, huge thermal inertia couple that with a pan with a high
thermal inertia is just asking for trouble unless you are happy to wait
for half an hour for things to warm up or can accurately guess when to
knock the setting down to avoid a massive overshoot.

Ceramic hobs also have some thermal inertia but not quite as bad as a
solid plate. Big snag with a ceramic hob is that it get fking hot, so any
spills almost instantly burn. Do ceramic hobs still come with a supplied
scraper? As others have said heavy pans and ceramic hobs are a bit of an
accident waiting to happen. Not so much the ordinary, controlled, putting
down but when a pan slips in the grip for some reason and drops onto the
hob...

I've only got a cheapy portable single pan 2 kW induction hob (£25 Lidl)
but I'm sold on it over any other form of electric hob cooking.

--
Cheers
Dave.

[Alexander Lamaison]

To my untrained eye, ceramic and induction hobs both look like a flat
sheet of glass. Don't induction hobs shatter in the same way with a
heavy pan?

[polygonum]

I used the word ceramic to cover all hobs which have a sheet of ceramic
as their top layer - regardless of the technology used to make pans
sitting on top get hot. So yes, that would include induction hobs
(unless there are any which are non-ceramic topped?)

--
Rod

[Alexander Lamaison]

So, just to get this clear:

- Solid metal hob take too long to warm them up
- Non-induction ceramic take too long and shatter
- Induction shatter

That means cast iron pans are only any good with gas? Surely not.

[polygonum]

You are missing Agas and their brethren.

They actually work fine on solid metal plates within the restrictions of
being slow and staying hot for ages. Experience does help - eventually!

But for us, their sheer weight is an overriding problem - partner has
illness issues that restrict her ability to pick up heavy things. So
stainless (and as mentioned earlier, they do have aluminium or whatever
layers on the base) was the only viable choice.

--
Rod

[Dave Liquorice]

On 21 Mar 2013 09:43:22 GMT, Huge wrote:

>> I've only got a cheapy portable single pan 2 kW induction hob (£25

>> Lidl) but I'm sold on it over any other form of electric hob cooking.
>

> But it still isn't as good as gas at simmering. But I bring stuff to
> the boil on it all the time.

I use it in preference to the solid hot plate cooke, even though it takes
up 1/3 of the total work surafce in the kitchen and doesn't live their
either. I generally use the "power level" settings and find 1 is about
right for a simmer. I haven't really played with the "pan temperature"
mode but I suspect that 100C (the default is 120C) and a higher power
level would give a very even gentle simmer.

--
Cheers
Dave.

[Antonio B]

replying to GB, Antonio B wrote:
Thanks for that. I gave it a try but, the jam seems to be stratified with the
sugar centrifuged to a pellet at the bottom of the pan and the liquid
suspension at the top. There is also a layer of condensed lead that may have
vaporised from the brass pan as it heated up during the reverse spin cycle. Do
you have any recommendations for a bench top sonicator to resuspend the fruit
pulp? Sorry for the late reply, the spinning pan created some high frequency
EM radio waves which played hell with my WiFi router, so only back online now

--
for full context, visit https://www.homeownershub.com/uk-diy/induction-hob-and-old-brass-pan-881322-.htm