expanding foam - tolerate high temps?

Jim K

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Aug 9, 2010, 3:51:48 AM8/9/10

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thinking to insulate some 28mm boiler return pipes with expanding foam
- any gotchas?

i expect max temp to be 85deg C... does it degrade at high temps? or
anything else undesirable? fire rated safer than ordinary? ??

cheers
Jim K

d...@gglz.com

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Aug 9, 2010, 4:36:00 AM8/9/10

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On some boilers, the manufacturers instructions say that a certain
length of pipe (both feed and return) must be left uninsulated.

Jim K

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Aug 9, 2010, 4:56:27 AM8/9/10

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how long and any ideas why?

ta
Jim K

d...@gglz.com

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Aug 9, 2010, 5:36:05 AM8/9/10

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I think it's in case the pump circulation cuts off unexpectedly (e.g.
power cut), and the boiler needs to dissipate the residual heat in the
heat exchanger.

Part timer

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Aug 9, 2010, 10:15:37 AM8/9/10

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Don't know about your application but on Top Gear, Richard Hammond
tried to use it around hot engine parts on his 'damper van'. Ended up
suffering the consequences.

Jim K

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Aug 9, 2010, 10:39:50 AM8/9/10

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On 9 Aug, 15:15, Part timer <hhmnos...@googlemail.com> wrote:

> Don't know about your application but on Top Gear, Richard Hammond
> tried to use it around hot engine parts on his 'damper van'. Ended up
> suffering the consequences.

can we presume they were a lot hotter than 85deg C tho? i.e. 85 deg C
is "hot cup of tea" realm....spose a boiling water test is required...

cheers Jim K

The Natural Philosopher

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Aug 9, 2010, 10:46:57 AM8/9/10

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it will char at several hundred. Its fine up to 100C.

test by putting bits in boiling water?

Phil L

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Aug 9, 2010, 12:34:41 PM8/9/10

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It does degrade slightly, it goes brittle, similar to that gritty sponge
stuff that flower arrangements are put into, although not to that extent,
but I wouldn't use it for this purpose if I were you, simply because it's a
PITA if you ever want to work on the pipes again, far better to use the
split foam pipe insulation, easily removed, less mess and cheap as chips.

--
Phil L
RSRL Tipster Of The Year 2008

Jim K

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Aug 9, 2010, 2:50:10 PM8/9/10

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mmm that's where I am starting from!! crap thin stuff - move upto the
right stuff in right size and costs *a lot* more....

Pipes connected to my heat bank are radiating a lot of heat... I've
insulated the heat bank externals (pipes, pumps, heat Xchanger etc)
with 2 X £8 cylinder jackets - which are working well

last few obvious heat sinks now - boiler flow is worst, thought I'd do
return as well

the gritty brittleness - is that from UV exposure? sounds like what it
does in sun - these pipes never see the sun!!

Cheers
Jim K

Phil L

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Aug 9, 2010, 3:15:20 PM8/9/10

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Jim K wrote:
> On 9 Aug, 17:34, "Phil L" <neverchec...@hotmail.com> wrote:
>> Jim K wrote:
>>> thinking to insulate some 28mm boiler return pipes with expanding
>>> foam - any gotchas?
>>
>>> i expect max temp to be 85deg C... does it degrade at high temps? or
>>> anything else undesirable? fire rated safer than ordinary? ??
>>
>>> cheers
>>> Jim K
>>
>> It does degrade slightly, it goes brittle, similar to that gritty
>> sponge stuff that flower arrangements are put into, although not to
>> that extent, but I wouldn't use it for this purpose if I were you,
>> simply because it's a PITA if you ever want to work on the pipes
>> again, far better to use the split foam pipe insulation, easily
>> removed, less mess and cheap as chips.
>
> mmm that's where I am starting from!! crap thin stuff - move upto the
> right stuff in right size and costs *a lot* more....
>
> Pipes connected to my heat bank are radiating a lot of heat... I've
> insulated the heat bank externals (pipes, pumps, heat Xchanger etc)
> with 2 X £8 cylinder jackets - which are working well
>

Cylinder jackets are thin fibreglass wrapped in a plastic bag, why not lag
your pipes with fibreglass too?

> last few obvious heat sinks now - boiler flow is worst, thought I'd do
> return as well
>
> the gritty brittleness - is that from UV exposure? sounds like what it
> does in sun - these pipes never see the sun!!

It could be UV attack as it's outside that I've noticed it happening

Dave

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Aug 9, 2010, 3:52:49 PM8/9/10

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I wish this question had been asked last night, I was drinking with
Baxi's ex director of development. If he comes in the pub again I'll ask
and post back.

Dave

Jim K

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Aug 9, 2010, 4:06:33 PM8/9/10

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ta ;>)

Tabby

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Aug 10, 2010, 3:18:07 AM8/10/10

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You could wrap felt pipe insulation over the split foam insulation.

NT

Jim K

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Aug 10, 2010, 5:58:30 AM8/10/10

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well I could do ...
but for a 4quid foam can plus moulds (spare bits of 110 soil piipe
split in two or "hinged") I reckon I can cover lots of pipe as thick
as I like.. unless the foam won't behave...

Jim K

Grimly Curmudgeon

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Aug 10, 2010, 11:26:26 AM8/10/10

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We were somewhere around Barstow, on the edge of the desert, when the
drugs began to take hold. I remember Jim K <jk98...@googlemail.com>
saying something like:

>> > mmm that's where I am starting from!! crap thin stuff - move upto the
>> > right stuff in right size and costs *a lot* more....

Two layers of the cheap stuff - tie-wraps around the big size. You can
get various sizes of it to fit nicely together.

>well I could do ...
>but for a 4quid foam can plus moulds (spare bits of 110 soil piipe
>split in two or "hinged") I reckon I can cover lots of pipe as thick
>as I like.. unless the foam won't behave...

Go for it - after all, that's exactly what some very pricey underground
hot water pipe is made from, from what I've seen. How about 25quid a
metre?

Rick Hughes

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Aug 11, 2010, 11:34:51 AM8/11/10

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"Tabby" <meow...@care2.com> wrote in message
news:1977c869-123f-4a77...@s9g2000yqd.googlegroups.com...

On Aug 9, 7:50 pm, Jim K <jk989...@googlemail.com> wrote:
> On 9 Aug, 17:34, "Phil L" <neverchec...@hotmail.com> wrote:
>

Why not use the fire proof caulk ... ideal for the job