What DOESN'T expanding foam stick to? I want to bridge a gap in the apex of
a roof, that foam would droop away from, so need to install a temporary
'shelf' until it has hardened.

Picture he

https://www.dropbox.com/s/o7czysxiil...x-Gap.jpg?dl=0


(Background: this is a barn with fibre cement roof that I had sprayed with
foam insulation some years ago, but they failed to seal the apex properly
despite claiming that they had. Access is extremely difficult as the barn is
full of immovable objects (large lathes, milling machines etc) and the apex
is about 15 foot up so it will have to be done in short sections - its about
40 foot long)

Andrew

On 09/04/2016 09:11, Andrew Mawson wrote:
What DOESN'T expanding foam stick to? I want to bridge a gap in the apex
of a roof, that foam would droop away from, so need to install a
temporary 'shelf' until it has hardened.

Idiot boy question: why not accept that expanding foam sticks to most
stuff and use as a "shelf" something that you are happy to leave there
which won't do any damage if they do fall off in time? Eg lengths cut
from polystyrene sheet?

--
Robin
reply-to address is (intended to be) valid

"Andrew Mawson" wrote in message
...
What DOESN'T expanding foam stick to? I want to bridge a gap in the apex of a roof,
that foam would droop away from, so need to install a temporary 'shelf' until it has
hardened.


Just cover whatever you use for "shelving" with polythene or
any other thin transparent sheeting as a barrier. Fixed on the
underside with drawing pins etc. To save the pins tearing the
plastic first reinforce the site of the pins with squares of duck
tape or similar.

The worst that can happen is that the barrier doesn't work
and it sticks but after pulling out the pins taking down the board
and trimming all you're left with are strips of transparent
polythene on the foam.

Or it might separate with no problems at all.

As was pointed out in a previous thread all plastics are
different, as in plastic sheeting and knowing the precise chemical
composition of what you have available, and so it may just be a
case of try it and see. ( I could go up in the loft right now and maybe
check out some old carrier bags which had been subject to
"foam abuse" but there would be little point)

Or maybe treating the polythene with a further barrier.


michael adams


....

On 09/04/2016 09:11, Andrew Mawson wrote:
What DOESN'T expanding foam stick to? I want to bridge a gap in the apex
of a roof, that foam would droop away from, so need to install a
temporary 'shelf' until it has hardened.

Picture he

https://www.dropbox.com/s/o7czysxiil...x-Gap.jpg?dl=0


(Background: this is a barn with fibre cement roof that I had sprayed
with foam insulation some years ago, but they failed to seal the apex
properly despite claiming that they had. Access is extremely difficult
as the barn is full of immovable objects (large lathes, milling machines
etc) and the apex is about 15 foot up so it will have to be done in
short sections - its about 40 foot long)

The classic GRP mould release system is to polish the mould with
silicone polish, over which you paint white PVA. The resin sticks to the
PVA, but that separates easily from the polish.


--
Colin Bignell

On 09/04/2016 09:11, Andrew Mawson wrote:
What DOESN'T expanding foam stick to? I want to bridge a gap in the apex
of a roof, that foam would droop away from, so need to install a
temporary 'shelf' until it has hardened.

Cover the shelf in (cooking) cling film.





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

On 09/04/16 09:11, Andrew Mawson wrote:
What DOESN'T expanding foam stick to? I want to bridge a gap in the apex
of a roof, that foam would droop away from, so need to install a
temporary 'shelf' until it has hardened.

Picture he

https://www.dropbox.com/s/o7czysxiil...x-Gap.jpg?dl=0


(Background: this is a barn with fibre cement roof that I had sprayed
with foam insulation some years ago, but they failed to seal the apex
properly despite claiming that they had. Access is extremely difficult
as the barn is full of immovable objects (large lathes, milling machines
etc) and the apex is about 15 foot up so it will have to be done in
short sections - its about 40 foot long)

Andrew

Cling film wrap the shelf - the cling film may or may not stick to the
foam, but that would not matter if it stayed up there presumably?

I used the cling film trick around door threshold oak strips when I
needed to embed the wood onto 3-4 big blobs of isopon to get a level
surface to mount the oak onto.

The oak lifted straight out and the cling film peeled off the isopon
leaving a perfectly moulded set of pads

On 09/04/16 09:55, Nightjar cpb wrote:
On 09/04/2016 09:11, Andrew Mawson wrote:
What DOESN'T expanding foam stick to? I want to bridge a gap in the apex
of a roof, that foam would droop away from, so need to install a
temporary 'shelf' until it has hardened.

Picture he

https://www.dropbox.com/s/o7czysxiil...x-Gap.jpg?dl=0


(Background: this is a barn with fibre cement roof that I had sprayed
with foam insulation some years ago, but they failed to seal the apex
properly despite claiming that they had. Access is extremely difficult
as the barn is full of immovable objects (large lathes, milling machines
etc) and the apex is about 15 foot up so it will have to be done in
short sections - its about 40 foot long)

The classic GRP mould release system is to polish the mould with
silicone polish, over which you paint white PVA. The resin sticks to the
PVA, but that separates easily from the polish.



The trick with concrete shuttering is a mixture of sump oil and diesel
(at least in the USA - probably would frowned upon here!)

"Andrew Mawson" Wrote in
message:
What DOESN'T expanding foam stick to?

A greased surface?

--
Jim K


----Android NewsGroup Reader----
http://usenet.sinaapp.com/

On 09/04/16 09:11, Andrew Mawson wrote:
What DOESN'T expanding foam stick to? I want to bridge a gap in the apex
of a roof, that foam would droop away from, so need to install a
temporary 'shelf' until it has hardened.

Picture he

https://www.dropbox.com/s/o7czysxiil...x-Gap.jpg?dl=0


(Background: this is a barn with fibre cement roof that I had sprayed
with foam insulation some years ago, but they failed to seal the apex
properly despite claiming that they had. Access is extremely difficult
as the barn is full of immovable objects (large lathes, milling machines
etc) and the apex is about 15 foot up so it will have to be done in
short sections - its about 40 foot long)

Andrew

why not use something covered with a sacrficial polythene sheet.
Clingflim or similar.


--
New Socialism consists essentially in being seen to have your heart in
the right place whilst your head is in the clouds and your hand is in
someone else's pocket.

"The Natural Philosopher" wrote in message
...

On 09/04/16 09:11, Andrew Mawson wrote:
What DOESN'T expanding foam stick to? I want to bridge a gap in the apex
of a roof, that foam would droop away from, so need to install a
temporary 'shelf' until it has hardened.

Picture he

https://www.dropbox.com/s/o7czysxiil...x-Gap.jpg?dl=0


(Background: this is a barn with fibre cement roof that I had sprayed
with foam insulation some years ago, but they failed to seal the apex
properly despite claiming that they had. Access is extremely difficult
as the barn is full of immovable objects (large lathes, milling machines
etc) and the apex is about 15 foot up so it will have to be done in
short sections - its about 40 foot long)

Andrew

why not use something covered with a sacrficial polythene sheet. Clingflim
or similar.



Thanks for all the suggestions

Andrew

I've just worked out roughly that it would take 13 750 mL cans of foam, so
maybe not a practical solution.

What I need is something like the foam pipe insulation you can get - ie a
sausage like shape - that I can push into the gap to seal it. But it needs
to be about 6 inch diameter and stiff enough to be poked in and stay with
it's own 'gription'

So where can I get 6" diameter stiff foam - 1 metre lengths would be
convenient, and i'd need a total of 13 metres of them !

Andrew

Candle wax, oils and greases generally?
Brian

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

Blind user, so no pictures please!
"Andrew Mawson" wrote in message
...
What DOESN'T expanding foam stick to? I want to bridge a gap in the apex
of a roof, that foam would droop away from, so need to install a temporary
'shelf' until it has hardened.

Picture he

https://www.dropbox.com/s/o7czysxiil...x-Gap.jpg?dl=0


(Background: this is a barn with fibre cement roof that I had sprayed with
foam insulation some years ago, but they failed to seal the apex properly
despite claiming that they had. Access is extremely difficult as the barn
is full of immovable objects (large lathes, milling machines etc) and the
apex is about 15 foot up so it will have to be done in short sections -
its about 40 foot long)

Andrew

On Saturday, 9 April 2016 09:10:55 UTC+1, Andrew Mawson wrote:
What DOESN'T expanding foam stick to? I want to bridge a gap in the apex of
a roof, that foam would droop away from, so need to install a temporary
'shelf' until it has hardened.

Picture he

https://www.dropbox.com/s/o7czysxiil...x-Gap.jpg?dl=0


(Background: this is a barn with fibre cement roof that I had sprayed with
foam insulation some years ago, but they failed to seal the apex properly
despite claiming that they had. Access is extremely difficult as the barn is
full of immovable objects (large lathes, milling machines etc) and the apex
is about 15 foot up so it will have to be done in short sections - its about
40 foot long)

Andrew

Cling film.

On Sat, 9 Apr 2016 15:04:25 +0100, "Andrew Mawson"
wrote:




Thanks for all the suggestions

Andrew

I've just worked out roughly that it would take 13 750 mL cans of foam, so
maybe not a practical solution.

What I need is something like the foam pipe insulation you can get - ie a
sausage like shape - that I can push into the gap to seal it. But it needs
to be about 6 inch diameter and stiff enough to be poked in and stay with
it's own 'gription'

So where can I get 6" diameter stiff foam - 1 metre lengths would be
convenient, and i'd need a total of 13 metres of them !

Andrew


Armaflex who make a lot of the pipe insulation also supply the same
material in sheet form .
https://www.pipelagging.com/product/...heet-2m-x-0.5m

You could cut sections out of that roll it up and push it in , they
also make a jointing tape and on a clean dry surface that sticks like
**** to blanket.

A tightwads option would be to cut up foam camping mats.

G.Harman

On Saturday, April 9, 2016 at 3:04:21 PM UTC+1, Andrew Mawson wrote:
"The Natural Philosopher" wrote in message
...

On 09/04/16 09:11, Andrew Mawson wrote:
What DOESN'T expanding foam stick to? I want to bridge a gap in the apex
of a roof, that foam would droop away from, so need to install a
temporary 'shelf' until it has hardened.

Picture he

https://www.dropbox.com/s/o7czysxiil...x-Gap.jpg?dl=0


(Background: this is a barn with fibre cement roof that I had sprayed
with foam insulation some years ago, but they failed to seal the apex
properly despite claiming that they had. Access is extremely difficult
as the barn is full of immovable objects (large lathes, milling machines
etc) and the apex is about 15 foot up so it will have to be done in
short sections - its about 40 foot long)

Andrew

why not use something covered with a sacrficial polythene sheet. Clingflim
or similar.



Thanks for all the suggestions

Andrew

I've just worked out roughly that it would take 13 750 mL cans of foam, so
maybe not a practical solution.

Dozen cans of foam is under 50 quid


What I need is something like the foam pipe insulation you can get - ie a
sausage like shape - that I can push into the gap to seal it. But it needs
to be about 6 inch diameter and stiff enough to be poked in and stay with
it's own 'gription'

So where can I get 6" diameter stiff foam - 1 metre lengths would be
convenient, and i'd need a total of 13 metres of them !

If you can find it, its the postage that will be a killer ;-)

Above can foam and poly layflat tubing usually used for packaging, foam fill in situ..

Andrew

On Saturday, 9 April 2016 09:10:55 UTC+1, Andrew Mawson wrote:
What DOESN'T expanding foam stick to? I want to bridge a gap in the apex of
a roof, that foam would droop away from, so need to install a temporary
'shelf' until it has hardened.

Picture he

https://www.dropbox.com/s/o7czysxiil...x-Gap.jpg?dl=0


(Background: this is a barn with fibre cement roof that I had sprayed with
foam insulation some years ago, but they failed to seal the apex properly
despite claiming that they had. Access is extremely difficult as the barn is
full of immovable objects (large lathes, milling machines etc) and the apex
is about 15 foot up so it will have to be done in short sections - its about
40 foot long)

Andrew

You have another problem too.
Expanding foam turns into one huge hollow bubble if too thick.
ie you can't fill voluminous spaces with it.

It needs moisture to go off too. So wet down slightly in the place you out it in.

On 09/04/2016 09:11, Andrew Mawson wrote:
What DOESN'T expanding foam stick to? I want to bridge a gap in the apex
of a roof, that foam would droop away from, so need to install a
temporary 'shelf' until it has hardened.

Picture he

https://www.dropbox.com/s/o7czysxiil...x-Gap.jpg?dl=0


(Background: this is a barn with fibre cement roof that I had sprayed
with foam insulation some years ago, but they failed to seal the apex
properly despite claiming that they had. Access is extremely difficult
as the barn is full of immovable objects (large lathes, milling machines
etc) and the apex is about 15 foot up so it will have to be done in
short sections - its about 40 foot long)

Andrew

Maybe an appropriate form of silicone?

http://www.wacker.com/cms/en/industr...GB&language=en

--
Rod

On 09/04/2016 10:10, alan_m wrote:
On 09/04/2016 09:11, Andrew Mawson wrote:
What DOESN'T expanding foam stick to? I want to bridge a gap in the apex
of a roof, that foam would droop away from, so need to install a
temporary 'shelf' until it has hardened.

Cover the shelf in (cooking) cling film.






+1

Mike

cut kingspan with a blunt woodwork saw ,
jam it in the gap,
use a foam gun to seal the gaps

[g]

On 09/04/2016 15:04, Andrew Mawson wrote:

I've just worked out roughly that it would take 13 750 mL cans of foam,
so maybe not a practical solution.

Quite bizarrely I was just about to post a question as to the "quality"
of ToolStation expanding foam as I have 6 new windows to fit this weekend.

http://www.toolstation.com/shop/Adhe...12+Pack/p36594

12 cans of gun grade or hand held for £44 (£3.60 a tin)

Bought a gun the other day but ToolStation also do a good price for one.

OR IS THE GAP AT THE RIDGE FOR VENTILATION?

"DICEGEORGE" wrote in message
...

OR IS THE GAP AT THE RIDGE FOR VENTILATION?

George,

Yes it was for ventilation originally when it was a cow barn, but my CNC
machines don't fart as much as cows

Andrew

On Fri, 15 Apr 2016 13:32:30 +0100, Andrew Mawson wrote:

"DICEGEORGE" wrote in message
...

OR IS THE GAP AT THE RIDGE FOR VENTILATION?

George,

Yes it was for ventilation originally when it was a cow barn, but my CNC
machines don't fart as much as cows

I have this vision of a farmer having a cowshed like this, with the
ventilation led to a vertical pipe in the corner and a permanent 'flare'
as on an oil rig.