What DOESN'T expanding foam stick to?

I want to make a few rectangular slabs of dense expanding polyurathane
foam about 150mm x 150mm x 50mm. and intend to just make a box shape
and 'squirt the foam and close the lid" - what can I cover the sides
with that the foam WON'T stick to?
AWEM
Reply to
Andrew Mawson
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In my experience, the bloody stuff *won't* stick to whatever I want it to stick to at the time...but that's another story... ;-)
Why not line the box with a poly bag? or maybe clingfilm? Not sure that the plastic sheet will come away from it after, but will that matter?
Regards, Tony
Reply to
Tony Jeffree
I think you may need to ensure that there's a little moisture in there before you start, otherwise it may not cure.
Cheers Tim
Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service
Reply to
Tim Leech
Definitely not Gert's fried egg. That sticks to non stick, the kitchen floor, the cat and space shuttle tiles. -- Regards,
John Stevenson Nottingham, England.
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Reply to
John Stevenson
I've used the clingfilm method - the foam sticks to it, but that can actually be an advantage for a nice clean finish.
You could also try a sheet of baking teflon ( most decent cookware shops, comes in a sheet about 18" x 18" ). I haven't used it with foam, but I haven't found anything yet that will stick to it.
I've tried coating surfaces with a number of different materials ( beeswax etc. ) but the results have been less than wonderful, probably due to the solvents in play.
Regards,
Reply to
Stephen Howard
It's very hard to avoid the temptation to squirt too much, & in a closed space that may very well not foam properly (or cure properly?)
Cheers Tim Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service
Reply to
Tim Leech
IamTheWalrus
I suppose John is the Egg man?
Cheers Tim
Dutton Dry-Dock Traditional & Modern canal craft repairs Vintage diesel engine service
Reply to
Tim Leech
And a large volume of foam that doesn't cure quickly will go on expanding for several days, long after the box has been sealed.
Cliff Coggin Kent UK
Reply to
Cliff Coggin
I've used polythene before, but you have to be careful not to get any creases in it otherwise it won't peel off. Definately go for the the two part type of foam, I tried casting a block of the stuff from an aerosol can and the results were terrible (just a big sticky mess -even after I put some water in).
Regards
Kevin
PS this is one case where you should follow the instructions and wear plastic gloves. Don't know if it is particularly dangerous on skin but I know nothing gets it off!
Reply to
Kevin Steele
This should give you all a laugh.. found on the net. all the best..mark
A friend of mine once built a canoe. He spent a long time on it and it was a work of art.Almost the final phase was to fill both ends with polyurethane expanding foam.He duly ordered the bits from Mr Glasplies (an excellent purveyor of all things fibreglass) and it arrived in two packs covered with appropriately dire warnings about expansion ratios and some very good notes on how to use it.Unfortunately he had a degree, worse still two of them. One was in Chemistry, so the instructions got thrown away and the other in something mathematical because in a few minutes he was merrily calculating the volume of his craft to many decimal places and the guidelines got binned as well.He propped the canoe up on one end, got a huge tin, carefully measured the calculated amounts of glop, mixed them and quickly poured the mixture in the end of the canoe (The two pack expands very rapidly). I arrived as he was completing this and I looked in to see the end chamber over half full of something Cawdors Witches would have been proud of. Two thing occurred to me, one was the label which said in big letters: "Caution - expansion ration 50:1" (or something similar) and the other that the now empty tins said "approximately enough for 20 small craft"Any comment was drowned out by a sea of yellow brown foam suddenly pouring out of the middle of the canoe and the end of the canoe bursting open. My friend screamed and leapt at his pride and joy which was knocked to the ground as he started trying to bale handfuls of this stuff out with his hands.Knocking the craft over allowed the still liquid and not yet fully expanded foam to flow to the other end of the canoe where it expanded and shattered that end as well.A few seconds later and we had a canoe with two exploded ends, a mountain of solid foam about 4ft high growing out of the middle, and a chemist firmly embedded up to his armpits in it.At this stage he discovered the reaction was exothermic and his hands and arms were getting very hot indeed. Running about in small circles in a confined space while glued to the remains of a fairly large canoe proved ineffective so he resorted to screaming a bit instead.Fortunately a Kukri was to hand so I attacked the foam around his hands with some enthusiasm. The process was hindered by the noise he was making and the fact he was trying to escape while still attached to the canoe.Eventually I managed to hack out a lump of foam still including most of his arms and hands. Unfortunately my tears of laughter were not helping as they accelerated the foam setting.Seeking medical help was obviously out of the question, the embarrassment of having to explain his occupation (Chief Research Chemist at a major petrochemical organisation) would simply never have been lived down. Several hours and much acrimony later we had removed sufficient foam (and much hair) to allow him to move again. However he still looked something like a failed audition for Quasimodo with red burns on his arms and expanded blobs of foam sticking everywhere. My comment that the scalding simple made the hairs the foam was sticking to come out easier was not met with the enthusiasm I felt it deserved.I forgot to add that in retrospect rather unwisely he had set out to do this deed in the hallway of his house (the only place he later explained with sufficient headroom for the canoe - achieved by poking it up the stairwell.Having extricated him we now were faced with the problem of a canoe construction kit embedded in a still gurgling block of foam which was now irrevocably bonded to the hall and stairs carpet as well as several banister rails and quite a lot of wallpaper.At this point his wife and her mother came back from shopping......Oh yes - and he had been wearing the pullover Mum in law had knitted him for his birthday the week before.
Reply to
mark
I'm sorry - that story is just so unrealistic - any self-respecting bodger would have been building the boat in the *kitchen* ;-)
Regards, Tony
Reply to
Tony Jeffree
Andrew Mawson wrote in message ...
Andrew,
Do you need to make your own blocks? how about using some offcuts of Kingspan or similar insulating material.Should be scroungable from a building site or keep an eye out for some in roadside skips. (maybe I should not encourage you in such practises!!)
Regards
Bob
Reply to
Bob Minchin
>Path: >uni-berlin.de!fu-berlin.de!postnews.google.com!o13g2000cwo.googlegroups.com!not-for-mail >From: "mark" >Newsgroups: uk.rec.models.engineering >Subject: Re: What DOESN'T expanding foam stick to? >Date: 2 Mar 2005 10:54:11 -0800 >Organization:
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76 >Message-ID: >References: >NNTP-Posting-Host: 81.86.79.138 >Mime-Version: 1.0 >Content-Type: text/plain; charset="iso-8859-1" >X-Trace: posting.google.com 1109789655 14091 127.0.0.1 (2 Mar 2005 >18:54:15 GMT) X-Complaints-To: snipped-for-privacy@google.com >NNTP-Posting-Date: Wed, 2 Mar 2005 18:54:15 +0000 (UTC) >In-Reply-To: >User-Agent: G2/0.2 >Complaints-To: snipped-for-privacy@google.com >Injection-Info: o13g2000cwo.googlegroups.com; posting-host=81.86.79.138; > posting-account=3f-VqwwAAAARK4rziYkkuvfb_vmCnFkQ >Xref: uni-berlin.de uk.rec.models.engineering:20762
>This should give you all a laugh.. >found on the net. >all the best..mark
>A friend of mine once built a canoe. He spent a long time >on it and it was a work of art.Almost the final phase was to fill both >ends with polyurethane >expanding foam.He duly ordered the bits from Mr Glasplies (an excellent >purveyor of all things fibreglass) and it arrived in two >packs covered with appropriately dire warnings about expansion ratios and >some very good notes on how to use it.Unfortunately he had a degree, >worse still two of them. One >was in Chemistry, so the instructions got thrown away
Reply to
jrlloyd

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