I want to squirt some expanding polyurethane foam into a section of
mdf box cladding covering some copper water pipes to cut down on
draughts (an insects) from getting into the kitchen. Since I want to
be able to remove the cladding if necesssary, what can I use as a
release agent to prevent the foam from sticking to the inside of the
cladding? The stuff seems to stick quite firmly to prety much
anything.

I'll remove the section of cladding before applying the foam, but then
replace it before the foam has set, to get a reasonable seal between
the two.

On 24/10/2017 10:11, Davidm wrote:
I want to squirt some expanding polyurethane foam into a section of
mdf box cladding covering some copper water pipes to cut down on
draughts (an insects) from getting into the kitchen. Since I want to
be able to remove the cladding if necesssary, what can I use as a
release agent to prevent the foam from sticking to the inside of the
cladding? The stuff seems to stick quite firmly to prety much
anything.

I'll remove the section of cladding before applying the foam, but then
replace it before the foam has set, to get a reasonable seal between
the two.

Line the piece of cladding with cling film may work?

On 24/10/2017 10:13, ss wrote:
On 24/10/2017 10:11, Davidm wrote:
I want to squirt some expanding polyurethane foam into a section of
mdf box cladding covering some copper water pipes to cut down on
draughts (an insects) from getting into the kitchen. Since I want to
be able to remove the cladding if necesssary, what can I use as a
release agent to prevent the foam from sticking to the inside of the
cladding? The stuff seems to stick quite firmly to prety much
anything.

I'll remove the section of cladding before applying the foam, but then
replace it before the foam has set, to get a reasonable seal between
the two.

Line the piece of cladding with cling film may work?

I think I would go for slightly thicker polythene sheet (in one piece).
Were you planning to let it mould over the pipes too? Does it matter if
it sticks to the MDF, so long as the MDF and foam come off as one piece?

On Tue, 24 Oct 2017 10:11:40 +0100, Davidm wrote:

Since I want to
be able to remove the cladding if necesssary, what can I use as a
release agent to prevent the foam from sticking to the inside of the
cladding? The stuff seems to stick quite firmly to prety much
anything.

It won't stick to polyethylene film, as such. Wrinkles and folds will hold the
film on the foam. Just leave the film in place. Bewa one hole, and you will
bond everything together.

Also: http://wiki.diyfaq.org.uk/index.php/Foam_toolbox_moulding

If someone would remind me how to upload photos to the Wiki, I could do that...


Thomas Prufer

On 24/10/2017 10:49, newshound wrote:
On 24/10/2017 10:13, ss wrote:
On 24/10/2017 10:11, Davidm wrote:
I want to squirt some expanding polyurethane foam into a section of
mdf box cladding covering some copper water pipes to cut down on
draughts (an insects) from getting into the kitchen. Since I want to
be able to remove the cladding if necesssary, what can I use as a
release agent to prevent the foam from sticking to the inside of the
cladding? The stuff seems to stick quite firmly to prety much
anything.

I'll remove the section of cladding before applying the foam, but then
replace it before the foam has set, to get a reasonable seal between
the two.

Line the piece of cladding with cling film may work?

I think I would go for slightly thicker polythene sheet (in one piece).
Were you planning to let it mould over the pipes too? Does it matter if
it sticks to the MDF, so long as the MDF and foam come off as one piece?

Thicker polythene (than clingfilm) and a quick blast of pledge before
putting the foam in would be my choice if I really didn't want it to
stick to stuff that was already there. Be aware that the expanding stuff
is very keen on expanding and if it can't get out from a space througha
hole will deform whatever it is inside making it bulge .

--
Regards,
Martin Brown

On 24/10/2017 10:54, Martin Brown wrote:
On 24/10/2017 10:49, newshound wrote:
On 24/10/2017 10:13, ss wrote:
On 24/10/2017 10:11, Davidm wrote:
I want to squirt some expanding polyurethane foam into a section of
mdf box cladding covering some copper water pipes to cut down on
draughts (an insects) from getting into the kitchen. Since I want to
be able to remove the cladding if necesssary, what can I use as a
release agent to prevent the foam from sticking to the inside of the
cladding? The stuff seems to stick quite firmly to prety much
anything.

I'll remove the section of cladding before applying the foam, but then
replace it before the foam has set, to get a reasonable seal between
the two.

Line the piece of cladding with cling film may work?

I think I would go for slightly thicker polythene sheet (in one
piece). Were you planning to let it mould over the pipes too? Does it
matter if it sticks to the MDF, so long as the MDF and foam come off
as one piece?

Thicker polythene (than clingfilm) and a quick blast of pledge before
putting the foam in would be my choice if I really didn't want it to
stick to stuff that was already there. Be aware that the expanding stuff
is very keen on expanding and if it can't get out from a space througha
hole will deform whatever it is inside making it bulge .

Also the solvent in it will melt some plastics...


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

On 24/10/2017 10:49, Thomas Prufer wrote:
On Tue, 24 Oct 2017 10:11:40 +0100, Davidm wrote:

Since I want to
be able to remove the cladding if necesssary, what can I use as a
release agent to prevent the foam from sticking to the inside of the
cladding? The stuff seems to stick quite firmly to prety much
anything.

It won't stick to polyethylene film, as such. Wrinkles and folds will hold the
film on the foam. Just leave the film in place. Bewa one hole, and you will
bond everything together.

Also: http://wiki.diyfaq.org.uk/index.php/Foam_toolbox_moulding

If someone would remind me how to upload photos to the Wiki, I could do that...

Once logged in, click on the "Upload File" link on the left.

To display your photo on a page just include:

[[image:Nameofphoto.jpg]]

(there are some other bits you can tack on the end if you want to
specify display sizes, captions etc)


--
Cheers,

John.

/================================================== ===============\
| Internode Ltd - http://www.internode.co.uk |
|-----------------------------------------------------------------|
| John Rumm - john(at)internode(dot)co(dot)uk |
\================================================= ================/

Butter? Might pong a bit after a while though!
How about lining the area with cling film or something similar before you
squirt?
Brian

--
----- -
This newsgroup posting comes to you directly from...
The Sofa of Brian Gaff...

Blind user, so no pictures please!
"Davidm" wrote in message
...
I want to squirt some expanding polyurethane foam into a section of
mdf box cladding covering some copper water pipes to cut down on
draughts (an insects) from getting into the kitchen. Since I want to
be able to remove the cladding if necesssary, what can I use as a
release agent to prevent the foam from sticking to the inside of the
cladding? The stuff seems to stick quite firmly to prety much
anything.

I'll remove the section of cladding before applying the foam, but then
replace it before the foam has set, to get a reasonable seal between
the two.

On Tue, 24 Oct 2017 10:49:01 +0100, newshound
wrote:

On 24/10/2017 10:13, ss wrote:
On 24/10/2017 10:11, Davidm wrote:
I want to squirt some expanding polyurethane foam into a section of
mdf box cladding covering some copper water pipes to cut down on
draughts (an insects) from getting into the kitchen. Since I want to
be able to remove the cladding if necesssary, what can I use as a
release agent to prevent the foam from sticking to the inside of the
cladding? The stuff seems to stick quite firmly to prety much
anything.

I'll remove the section of cladding before applying the foam, but then
replace it before the foam has set, to get a reasonable seal between
the two.

Line the piece of cladding with cling film may work?

I think I would go for slightly thicker polythene sheet (in one piece).
Were you planning to let it mould over the pipes too? Does it matter if
it sticks to the MDF, so long as the MDF and foam come off as one piece?
It needs to go around the back of the pipes, so don't want it to stick
to the cladding. Cooking foil might be an alternative (comments about
cling film dissolving noted).

It says on the can that it's ok to use on electric cables, but is it
really (if it will dissolve some plastics)? Might have to put
something over the cables.

On 24/10/2017 12:46, Davidm wrote:
On Tue, 24 Oct 2017 10:49:01 +0100, newshound
wrote:

On 24/10/2017 10:13, ss wrote:

Line the piece of cladding with cling film may work?

I think I would go for slightly thicker polythene sheet (in one piece).
Were you planning to let it mould over the pipes too? Does it matter if
it sticks to the MDF, so long as the MDF and foam come off as one piece?
It needs to go around the back of the pipes, so don't want it to stick
to the cladding. Cooking foil might be an alternative (comments about
cling film dissolving noted).

It says on the can that it's ok to use on electric cables, but is it
really (if it will dissolve some plastics)? Might have to put
something over the cables.

Test it on some spare cable. My instinct is that it won't touch PVC at
all but will dissolve/destroy expanded polystyrene very quickly indeed.

--
Regards,
Martin Brown

On Tuesday, 24 October 2017 10:11:42 UTC+1, Davidm wrote:
I want to squirt some expanding polyurethane foam into a section of
mdf box cladding covering some copper water pipes to cut down on
draughts (an insects) from getting into the kitchen. Since I want to
be able to remove the cladding if necesssary, what can I use as a
release agent to prevent the foam from sticking to the inside of the
cladding? The stuff seems to stick quite firmly to prety much
anything.

I'll remove the section of cladding before applying the foam, but then
replace it before the foam has set, to get a reasonable seal between
the two.

Sounds like a recipe for damage. The trouble with these expanding foams is they set solid THEN they expand forcefully in all directions.


NT

On Tuesday, 24 October 2017 10:11:42 UTC+1, Davidm wrote:
I want to squirt some expanding polyurethane foam into a section of
mdf box cladding covering some copper water pipes to cut down on
draughts (an insects) from getting into the kitchen. Since I want to
be able to remove the cladding if necesssary, what can I use as a
release agent to prevent the foam from sticking to the inside of the
cladding? The stuff seems to stick quite firmly to prety much
anything.

I'll remove the section of cladding before applying the foam, but then
replace it before the foam has set, to get a reasonable seal between
the two.

The foam needs moisture to expand and set.
So it won't work.
You can spray some water into the void before the foam but the results aren't very neat.
Boats/cavity walls etc use two component stuff you have to mix.
In practice it's mixed in the spray gun at the nozzle.

On 24/10/2017 10:13 AM, ss wrote:
On 24/10/2017 10:11, Davidm wrote:
I want to squirt some expanding polyurethane foam into a section of
mdf box cladding covering some copper water pipes to cut down on
draughts (an insects) from getting into the kitchen. Since I want to
be able to remove the cladding if necesssary, what can I use as a
release agent to prevent the foam from sticking to the inside of the
cladding? The stuff seems to stick quite firmly to prety much
anything.

I'll remove the section of cladding before applying the foam, but then
replace it before the foam has set, to get a reasonable seal between
the two.

Line the piece of cladding with cling film may work?


Would a dense wool type of thing not do a similar job?

On 24/10/17 10:11, Davidm wrote:
I want to squirt some expanding polyurethane foam into a section of
mdf box cladding covering some copper water pipes to cut down on
draughts (an insects) from getting into the kitchen. Since I want to
be able to remove the cladding if necesssary, what can I use as a
release agent to prevent the foam from sticking to the inside of the
cladding? The stuff seems to stick quite firmly to prety much
anything.

I'll remove the section of cladding before applying the foam, but then
replace it before the foam has set, to get a reasonable seal between
the two.

try dried PVA

ISTR that is used at least for polyester resin

Obviously test first.

--
Outside of a dog, a book is a man's best friend. Inside of a dog it's
too dark to read.

Groucho Marx

On 24/10/2017 16:38, wrote:

Sounds like a recipe for damage. The trouble with these expanding foams is they set solid THEN they expand forcefully in all directions.


My recent experience with a one part x50 expanding foam from a gun was
that the resulting foam wasn't particularly dense or strong and I guess
that further expansion would have been contained if the former was
reasonably stiff and was securely fastened down.

https://www.toolstation.com/shop/Adh...ng+Foam/p57280

I will admit that I could see where all the foam was going and I did
have a few test squirts to see how much it would expand.

Don't the one part expanding foams come in different expansion versions?

http://www.diyfaq.org.uk/humour.html#foam





--
mailto: news {at} admac {dot] myzen {dot} co {dot} uk

On Tuesday, 24 October 2017 19:08:44 UTC+1, alan_m wrote:
On 24/10/2017 16:38, tabbypurr wrote:

Sounds like a recipe for damage. The trouble with these expanding foams is they set solid THEN they expand forcefully in all directions.


My recent experience with a one part x50 expanding foam from a gun was
that the resulting foam wasn't particularly dense or strong and I guess
that further expansion would have been contained if the former was
reasonably stiff and was securely fastened down.

https://www.toolstation.com/shop/Adh...ng+Foam/p57280

I will admit that I could see where all the foam was going and I did
have a few test squirts to see how much it would expand.

Don't the one part expanding foams come in different expansion versions?

they must, the last ones I used expanded with some serious force.

NT

http://www.diyfaq.org.uk/humour.html#foam