Neoprene thickness - or not?

"David Walker" <stuff@scuby.co.uk> wrote in message
news:d0fj04$hmc$1@wisteria.csv.warwick.ac.uk...
>> Indeed there are more bubbles in thicker neoprene, but these bubbles get
>> less important with depth as they are squeezed out of existance.
>
> So maybe the fact that you've got more of them makes up for the fact that
> they got compressed?

More of them will be better than fewer of them as regards insulation, but
especially once compressed there may not be enough of them to matter in any
case.

Sure, inevitably, the more neoprene and the more air bubbles the better the
insulation. The crux of the matter, and I have been unable to find out
whether it has been determined, is whether or not the thermal conductivity
of neoprene is of the correct magnitude so that increasing or decreasing the
thickness of neoprene is a significant factor in the equation which
determines the rate of heat loss from a diver over the average one or two
dives.

If the thermal conductivity of neoprene IS a significant factor in the
equation, then a thicker suit makes more sense. If it is not a significant
factor, then wearing a good fitting suit will matter far more than the
thickness of that suit.



>
>> There is likely to be very little radiated heat as a proportion of the
>> whole, given the grand opportunities for heat loss by conduction and
>> where a good conductor of heat (any metal in this context, even the worst
>> of them) forms one of the layers.
>
> Not sure, but i'm not convinced that the titanium linings (as they call
> them) will be particularly good conductors of heat. This isn't a lump of
> metal, and infact I don't believe it is chemically the metal at all, isn't
> it titanium oxide or something, with completely different properties to
> the metal itself. If you touch a piece of metal that's been left out in
> the cold, it will conduct the heat away from your hand very quickly,
> making it feel very very cold. The lining of a wetsuit doesn't do
> anything like that when you touch it, and so if the titanium in the lining
> is a good conductor its not coming in easy contact with the skin and so
> not conducting the heat away from your body.

Yes - that may well be the answer. However it MAY be metallic titanium (I
have no idea) and it may still not feel cold to the touch if there is so
LITTLE titanium that the temperature drop your hand is subjected to is
imperceptible. Some years ago I wore certain garments which needed to be
anti-static. The label on the inside of the collar said the fibres were 66%
polyester, 33% cotton, 1% stainless steel. None of us ever found a thread of
steel, but the miniscule amount served to "short out" the garment and they
never felt cold when you put them on.

Ken

"David Walker" <stuff@scuby.co.uk> wrote in message
news:d0fj04$hmc$1@wisteria.csv.warwick.ac.uk...
>> Indeed there are more bubbles in thicker neoprene, but these bubbles get
>> less important with depth as they are squeezed out of existance.
>
> So maybe the fact that you've got more of them makes up for the fact that
> they got compressed?

More of them will be better than fewer of them as regards insulation, but
especially once compressed there may not be enough of them to matter in any
case.

Sure, inevitably, the more neoprene and the more air bubbles the better the
insulation. The crux of the matter, and I have been unable to find out
whether it has been determined, is whether or not the thermal conductivity
of neoprene is of the correct magnitude so that increasing or decreasing the
thickness of neoprene is a significant factor in the equation which
determines the rate of heat loss from a diver over the average one or two
dives.

If the thermal conductivity of neoprene IS a significant factor in the
equation, then a thicker suit makes more sense. If it is not a significant
factor, then wearing a good fitting suit will matter far more than the
thickness of that suit.



>
>> There is likely to be very little radiated heat as a proportion of the
>> whole, given the grand opportunities for heat loss by conduction and
>> where a good conductor of heat (any metal in this context, even the worst
>> of them) forms one of the layers.
>
> Not sure, but i'm not convinced that the titanium linings (as they call
> them) will be particularly good conductors of heat. This isn't a lump of
> metal, and infact I don't believe it is chemically the metal at all, isn't
> it titanium oxide or something, with completely different properties to
> the metal itself. If you touch a piece of metal that's been left out in
> the cold, it will conduct the heat away from your hand very quickly,
> making it feel very very cold. The lining of a wetsuit doesn't do
> anything like that when you touch it, and so if the titanium in the lining
> is a good conductor its not coming in easy contact with the skin and so
> not conducting the heat away from your body.

Yes - that may well be the answer. However it MAY be metallic titanium (I
have no idea) and it may still not feel cold to the touch if there is so
LITTLE titanium that the temperature drop your hand is subjected to is
imperceptible. Some years ago I wore certain garments which needed to be
anti-static. The label on the inside of the collar said the fibres were 66%
polyester, 33% cotton, 1% stainless steel. None of us ever found a thread of
steel, but the miniscule amount served to "short out" the garment and they
never felt cold when you put them on.

Ken

"David Walker" <stuff@scuby.co.uk> wrote in message
news:d0fj04$hmc$1@wisteria.csv.warwick.ac.uk...
>> Indeed there are more bubbles in thicker neoprene, but these bubbles get
>> less important with depth as they are squeezed out of existance.
>
> So maybe the fact that you've got more of them makes up for the fact that
> they got compressed?

More of them will be better than fewer of them as regards insulation, but
especially once compressed there may not be enough of them to matter in any
case.

Sure, inevitably, the more neoprene and the more air bubbles the better the
insulation. The crux of the matter, and I have been unable to find out
whether it has been determined, is whether or not the thermal conductivity
of neoprene is of the correct magnitude so that increasing or decreasing the
thickness of neoprene is a significant factor in the equation which
determines the rate of heat loss from a diver over the average one or two
dives.

If the thermal conductivity of neoprene IS a significant factor in the
equation, then a thicker suit makes more sense. If it is not a significant
factor, then wearing a good fitting suit will matter far more than the
thickness of that suit.



>
>> There is likely to be very little radiated heat as a proportion of the
>> whole, given the grand opportunities for heat loss by conduction and
>> where a good conductor of heat (any metal in this context, even the worst
>> of them) forms one of the layers.
>
> Not sure, but i'm not convinced that the titanium linings (as they call
> them) will be particularly good conductors of heat. This isn't a lump of
> metal, and infact I don't believe it is chemically the metal at all, isn't
> it titanium oxide or something, with completely different properties to
> the metal itself. If you touch a piece of metal that's been left out in
> the cold, it will conduct the heat away from your hand very quickly,
> making it feel very very cold. The lining of a wetsuit doesn't do
> anything like that when you touch it, and so if the titanium in the lining
> is a good conductor its not coming in easy contact with the skin and so
> not conducting the heat away from your body.

Yes - that may well be the answer. However it MAY be metallic titanium (I
have no idea) and it may still not feel cold to the touch if there is so
LITTLE titanium that the temperature drop your hand is subjected to is
imperceptible. Some years ago I wore certain garments which needed to be
anti-static. The label on the inside of the collar said the fibres were 66%
polyester, 33% cotton, 1% stainless steel. None of us ever found a thread of
steel, but the miniscule amount served to "short out" the garment and they
never felt cold when you put them on.

Ken

"David Walker" <stuff@scuby.co.uk> wrote in message
news:d0fj04$hmc$1@wisteria.csv.warwick.ac.uk...
>> Indeed there are more bubbles in thicker neoprene, but these bubbles get
>> less important with depth as they are squeezed out of existance.
>
> So maybe the fact that you've got more of them makes up for the fact that
> they got compressed?

More of them will be better than fewer of them as regards insulation, but
especially once compressed there may not be enough of them to matter in any
case.

Sure, inevitably, the more neoprene and the more air bubbles the better the
insulation. The crux of the matter, and I have been unable to find out
whether it has been determined, is whether or not the thermal conductivity
of neoprene is of the correct magnitude so that increasing or decreasing the
thickness of neoprene is a significant factor in the equation which
determines the rate of heat loss from a diver over the average one or two
dives.

If the thermal conductivity of neoprene IS a significant factor in the
equation, then a thicker suit makes more sense. If it is not a significant
factor, then wearing a good fitting suit will matter far more than the
thickness of that suit.



>
>> There is likely to be very little radiated heat as a proportion of the
>> whole, given the grand opportunities for heat loss by conduction and
>> where a good conductor of heat (any metal in this context, even the worst
>> of them) forms one of the layers.
>
> Not sure, but i'm not convinced that the titanium linings (as they call
> them) will be particularly good conductors of heat. This isn't a lump of
> metal, and infact I don't believe it is chemically the metal at all, isn't
> it titanium oxide or something, with completely different properties to
> the metal itself. If you touch a piece of metal that's been left out in
> the cold, it will conduct the heat away from your hand very quickly,
> making it feel very very cold. The lining of a wetsuit doesn't do
> anything like that when you touch it, and so if the titanium in the lining
> is a good conductor its not coming in easy contact with the skin and so
> not conducting the heat away from your body.

Yes - that may well be the answer. However it MAY be metallic titanium (I
have no idea) and it may still not feel cold to the touch if there is so
LITTLE titanium that the temperature drop your hand is subjected to is
imperceptible. Some years ago I wore certain garments which needed to be
anti-static. The label on the inside of the collar said the fibres were 66%
polyester, 33% cotton, 1% stainless steel. None of us ever found a thread of
steel, but the miniscule amount served to "short out" the garment and they
never felt cold when you put them on.

Ken

"David Walker" <stuff@scuby.co.uk> wrote in message
news:d0fj04$hmc$1@wisteria.csv.warwick.ac.uk...
>> Indeed there are more bubbles in thicker neoprene, but these bubbles get
>> less important with depth as they are squeezed out of existance.
>
> So maybe the fact that you've got more of them makes up for the fact that
> they got compressed?

More of them will be better than fewer of them as regards insulation, but
especially once compressed there may not be enough of them to matter in any
case.

Sure, inevitably, the more neoprene and the more air bubbles the better the
insulation. The crux of the matter, and I have been unable to find out
whether it has been determined, is whether or not the thermal conductivity
of neoprene is of the correct magnitude so that increasing or decreasing the
thickness of neoprene is a significant factor in the equation which
determines the rate of heat loss from a diver over the average one or two
dives.

If the thermal conductivity of neoprene IS a significant factor in the
equation, then a thicker suit makes more sense. If it is not a significant
factor, then wearing a good fitting suit will matter far more than the
thickness of that suit.



>
>> There is likely to be very little radiated heat as a proportion of the
>> whole, given the grand opportunities for heat loss by conduction and
>> where a good conductor of heat (any metal in this context, even the worst
>> of them) forms one of the layers.
>
> Not sure, but i'm not convinced that the titanium linings (as they call
> them) will be particularly good conductors of heat. This isn't a lump of
> metal, and infact I don't believe it is chemically the metal at all, isn't
> it titanium oxide or something, with completely different properties to
> the metal itself. If you touch a piece of metal that's been left out in
> the cold, it will conduct the heat away from your hand very quickly,
> making it feel very very cold. The lining of a wetsuit doesn't do
> anything like that when you touch it, and so if the titanium in the lining
> is a good conductor its not coming in easy contact with the skin and so
> not conducting the heat away from your body.

Yes - that may well be the answer. However it MAY be metallic titanium (I
have no idea) and it may still not feel cold to the touch if there is so
LITTLE titanium that the temperature drop your hand is subjected to is
imperceptible. Some years ago I wore certain garments which needed to be
anti-static. The label on the inside of the collar said the fibres were 66%
polyester, 33% cotton, 1% stainless steel. None of us ever found a thread of
steel, but the miniscule amount served to "short out" the garment and they
never felt cold when you put them on.

Ken

"David Walker" <stuff@scuby.co.uk> wrote in message
news:d0fj04$hmc$1@wisteria.csv.warwick.ac.uk...
>> Indeed there are more bubbles in thicker neoprene, but these bubbles get
>> less important with depth as they are squeezed out of existance.
>
> So maybe the fact that you've got more of them makes up for the fact that
> they got compressed?

More of them will be better than fewer of them as regards insulation, but
especially once compressed there may not be enough of them to matter in any
case.

Sure, inevitably, the more neoprene and the more air bubbles the better the
insulation. The crux of the matter, and I have been unable to find out
whether it has been determined, is whether or not the thermal conductivity
of neoprene is of the correct magnitude so that increasing or decreasing the
thickness of neoprene is a significant factor in the equation which
determines the rate of heat loss from a diver over the average one or two
dives.

If the thermal conductivity of neoprene IS a significant factor in the
equation, then a thicker suit makes more sense. If it is not a significant
factor, then wearing a good fitting suit will matter far more than the
thickness of that suit.



>
>> There is likely to be very little radiated heat as a proportion of the
>> whole, given the grand opportunities for heat loss by conduction and
>> where a good conductor of heat (any metal in this context, even the worst
>> of them) forms one of the layers.
>
> Not sure, but i'm not convinced that the titanium linings (as they call
> them) will be particularly good conductors of heat. This isn't a lump of
> metal, and infact I don't believe it is chemically the metal at all, isn't
> it titanium oxide or something, with completely different properties to
> the metal itself. If you touch a piece of metal that's been left out in
> the cold, it will conduct the heat away from your hand very quickly,
> making it feel very very cold. The lining of a wetsuit doesn't do
> anything like that when you touch it, and so if the titanium in the lining
> is a good conductor its not coming in easy contact with the skin and so
> not conducting the heat away from your body.

Yes - that may well be the answer. However it MAY be metallic titanium (I
have no idea) and it may still not feel cold to the touch if there is so
LITTLE titanium that the temperature drop your hand is subjected to is
imperceptible. Some years ago I wore certain garments which needed to be
anti-static. The label on the inside of the collar said the fibres were 66%
polyester, 33% cotton, 1% stainless steel. None of us ever found a thread of
steel, but the miniscule amount served to "short out" the garment and they
never felt cold when you put them on.

Ken

"David Walker" <stuff@scuby.co.uk> wrote in message

edit

> If you touch a piece of metal that's been left out in the cold, it will
> conduct the heat away from your hand very quickly, making it feel very
> very cold.

It depends on the specific heat capacity of the element/alloy concerned.
Sodium for one will make you hand feel very very hot.

Keith

"David Walker" <stuff@scuby.co.uk> wrote in message

edit

> If you touch a piece of metal that's been left out in the cold, it will
> conduct the heat away from your hand very quickly, making it feel very
> very cold.

It depends on the specific heat capacity of the element/alloy concerned.
Sodium for one will make you hand feel very very hot.

Keith

"David Walker" <stuff@scuby.co.uk> wrote in message

edit

> If you touch a piece of metal that's been left out in the cold, it will
> conduct the heat away from your hand very quickly, making it feel very
> very cold.

It depends on the specific heat capacity of the element/alloy concerned.
Sodium for one will make you hand feel very very hot.

Keith

"David Walker" <stuff@scuby.co.uk> wrote in message

edit

> If you touch a piece of metal that's been left out in the cold, it will
> conduct the heat away from your hand very quickly, making it feel very
> very cold.

It depends on the specific heat capacity of the element/alloy concerned.
Sodium for one will make you hand feel very very hot.

Keith