dracken1
13-02-2005, 08:19 PM
thought i'd share this with you.
it's taken from a fibreglass forum and concerns the use of expanding foam.
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.
--
it's taken from a fibreglass forum and concerns the use of expanding foam.
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.
--