Expanding foam aerosols
Discussion
I had a decent enough experience, in truth. I wanted to fill the gap under my plasterboard walls with the foam as there were a few short bits without skirting and a family of mice were popping in. All the tales of doom and woe made me do it rather cautiously at first, and I would have done a far neater job if I'd been bolder (as I did on the second tranch).
Just don't squirt it into an enclosed space.
Just don't squirt it into an enclosed space.
I used to work in a DIY shop, along with quite a few other young lads. One of our bright ideas was to chop one of the large (about 1l) cans of expanding foam in half with a shovel.
Needless to say, yes, it did end in disaster - once it dries you just cant get it off, especially from hair. Its bad enough whin its on the hairs on our head, worse on your arms, but eyelashes is where you really start to regret it
Needless to say, yes, it did end in disaster - once it dries you just cant get it off, especially from hair. Its bad enough whin its on the hairs on our head, worse on your arms, but eyelashes is where you really start to regret it
Defcon5 said:
I used to work in a DIY shop, along with quite a few other young lads. One of our bright ideas was to chop one of the large (about 1l) cans of expanding foam in half with a shovel.
Needless to say, yes, it did end in disaster - once it dries you just cant get it off, especially from hair. Its bad enough whin its on the hairs on our head, worse on your arms, but eyelashes is where you really start to regret it
PMSL Needless to say, yes, it did end in disaster - once it dries you just cant get it off, especially from hair. Its bad enough whin its on the hairs on our head, worse on your arms, but eyelashes is where you really start to regret it
grumbledoak said:
It expands; if you squirt it into a closed space it will break something to expand further. And, it sticks. To anything. And you cannot get it off.
Otherwise, I found it quite effective.
OK, thanks GO. The stick thing I knew about, and is easily avoided by wearing old clothes and gloves. I didn't use it in a confined space so that's a useful lesson. (The job this evening also doesn't involve a confined space, so all's well there too.) Otherwise, I found it quite effective.
My experience is that it is very effective. Fills the space you squirt it into. Prevents drafts. Sticks things into place. Binds together loose bits. Sets very hard. Not expensive. Just a pain that a can never lasts for more than one job - use it and the nozzle is so bunged up that you can never use it again.
Oli.
grumbledoak said:
zcacogp said:
I'd quite like to hear of the pitfalls to be avoided.
IME:It expands; if you squirt it into a closed space it will break something to expand further. And, it sticks. To anything. And you cannot get it off.
Otherwise, I found it quite effective.
helps if you read the instructions too. You're not supposed to just stick the nozzle into a void and press the button till it's nearly full - if it's a big void build it up in 2 or 3 goes, wetting between each layer with a mist of water. Don't forget to mist with water first either if you want it to properly adhere and expand.
Most importantly, cover anything you don't want ruined, wear gloves and have ready a container that you can rest the nozzle in as it always releases a fair bit more over a few minutes. If it does go on something do NOT try and clean it off, let it set for a few hours then break it off - you'll end up with 1/10th the amount of damage.
zcacogp said:
Just a pain that a can never lasts for more than one job - use it and the nozzle is so bunged up that you can never use it again.
At the end, remove long plastic spout so you've just got the little trigger, turn can up the right way and squirt into something for a few seconds - if the can isn't upside down nothing will come out, the gas will clear the nozzle, then just remove the plastic bit and clean out with a tissue. I've been using one can for the last 3 weeks in bits n bobs.Davi said:
grumbledoak said:
zcacogp said:
I'd quite like to hear of the pitfalls to be avoided.
IME:It expands; if you squirt it into a closed space it will break something to expand further. And, it sticks. To anything. And you cannot get it off.
Otherwise, I found it quite effective.
helps if you read the instructions too. You're not supposed to just stick the nozzle into a void and press the button till it's nearly full - if it's a big void build it up in 2 or 3 goes, wetting between each layer with a mist of water. Don't forget to mist with water first either if you want it to properly adhere and expand.
Most importantly, cover anything you don't want ruined, wear gloves and have ready a container that you can rest the nozzle in as it always releases a fair bit more over a few minutes. If it does go on something do NOT try and clean it off, let it set for a few hours then break it off - you'll end up with 1/10th the amount of damage.
annodomini2 said:
I also thought one tip was to have a spray bottle with you and if you do put too much in keep spraying with water to stop it continuing expanding is this correct?
Can't say I've ever tried that - seeing that it expands better if the surfaces are wet I'd have thought it would have the opposite effect! Might give that a try later.http://www.diyfaq.org.uk/humour.html
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.
Peter Parry. http://www.wppltd.demon.co.uk
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.
Peter Parry. http://www.wppltd.demon.co.uk
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