Briefly: Perfectly good Fridge freezer has lots of rubbish clear plastic
internal parts like this door shelf:
http://www.espares.co.uk/datastore/p...ges/831356.jpg
without which the whole thing is pretty much a chuck out.

Model is discontinued, parts are unavailable so I am repairing again.

Previously repaired some broken polystyrene parts by patching with
polystyrene from CD boxes and plumbers' solvent adhesive. These repairs were
only partly successful, having lasted more than twelve months the
polystyrene has become crazed and crumbly and cracks are opening up again.

I was proposing to repair this time with epoxy resin in conjunction with
wood stifeners, plastic patches or maybe glass mat.

Will epoxy resin soften and destroy the polystyrene I am trying to repair?
Is there a better way to repair these things?

I know it's polystyrene because it is marked PS.

Tim W

On 13/05/2011 12:15, Tim W wrote:
Briefly: Perfectly good Fridge freezer has lots of rubbish clear plastic
internal parts like this door shelf:
http://www.espares.co.uk/datastore/p...ges/831356.jpg
without which the whole thing is pretty much a chuck out.

Model is discontinued, parts are unavailable so I am repairing again.

Previously repaired some broken polystyrene parts by patching with
polystyrene from CD boxes and plumbers' solvent adhesive. These repairs were
only partly successful, having lasted more than twelve months the
polystyrene has become crazed and crumbly and cracks are opening up again.

I was proposing to repair this time with epoxy resin in conjunction with
wood stifeners, plastic patches or maybe glass mat.

Will epoxy resin soften and destroy the polystyrene I am trying to repair?
Is there a better way to repair these things?

I know it's polystyrene because it is marked PS.

Tim W



If I remember rightly the solvent for Polystyrene is Benzene, nasty stuff.!!
Don

On 13/05/2011 12:15, Tim W wrote:
Briefly: Perfectly good Fridge freezer has lots of rubbish clear plastic
internal parts like this door shelf:
http://www.espares.co.uk/datastore/p...ges/831356.jpg
without which the whole thing is pretty much a chuck out.

Model is discontinued, parts are unavailable so I am repairing again.

Previously repaired some broken polystyrene parts by patching with
polystyrene from CD boxes and plumbers' solvent adhesive. These repairs were
only partly successful, having lasted more than twelve months the
polystyrene has become crazed and crumbly and cracks are opening up again.

I was proposing to repair this time with epoxy resin in conjunction with
wood stifeners, plastic patches or maybe glass mat.

Will epoxy resin soften and destroy the polystyrene I am trying to repair?
Is there a better way to repair these things?

I know it's polystyrene because it is marked PS.

Tim W



Do you really mean epoxy or are you referring to the car body repair kit
stuff more widely available. The 'glass fibre' kits from Halfords etc
are largely stabilised styrene monomer that is persuaded to polymerise
with the hardner. This should bond well to polystyrene unlike the pipe
solvent adhesive.

I'd try using the same technique as you used before but using the car
body filler kits (without the powder filler).

CD case material is a bad choice as it is pure polystyrene and subject
to stress cracking and crazing. The polystyrene sheets available in the
sheds would be better. Glass fibre matting to add further strength
would probably help but look a bit of a mess..

HTH

Chris K

Tim W wrote:
Briefly: Perfectly good Fridge freezer has lots of rubbish clear plastic
internal parts like this door shelf:
http://www.espares.co.uk/datastore/p...ges/831356.jpg
without which the whole thing is pretty much a chuck out.

Model is discontinued, parts are unavailable so I am repairing again.

Previously repaired some broken polystyrene parts by patching with
polystyrene from CD boxes and plumbers' solvent adhesive. These repairs were
only partly successful, having lasted more than twelve months the
polystyrene has become crazed and crumbly and cracks are opening up again.

I was proposing to repair this time with epoxy resin in conjunction with
wood stifeners, plastic patches or maybe glass mat.

Will epoxy resin soften and destroy the polystyrene I am trying to repair?
Is there a better way to repair these things?

hot glue.

as a model aircraft buff, the fast ways to repair PS have all been tried.

PVA works, but takes ages to dry.
Epoxy works, but is bloody expensive
Odourless CA works, but its enormously expensive and wont fill gaps.
Ordinary CA will reduce styrene to mush.
some contact glues..thixofix? the latex ones that smell of ammonia work
pretty well. No gap fill
Hot glue works briliantly, and ripped apart models will be flying in
minutes. stronger than the plastic is, fills gaps and glue melting point
JUST below styrene melting point.


I know it's polystyrene because it is marked PS.

Tim W

Donwill wrote:
On 13/05/2011 12:15, Tim W wrote:
Briefly: Perfectly good Fridge freezer has lots of rubbish clear plastic
internal parts like this door shelf:
http://www.espares.co.uk/datastore/p...ges/831356.jpg
without which the whole thing is pretty much a chuck out.

Model is discontinued, parts are unavailable so I am repairing again.

Previously repaired some broken polystyrene parts by patching with
polystyrene from CD boxes and plumbers' solvent adhesive. These
repairs were
only partly successful, having lasted more than twelve months the
polystyrene has become crazed and crumbly and cracks are opening up
again.

I was proposing to repair this time with epoxy resin in conjunction with
wood stifeners, plastic patches or maybe glass mat.

Will epoxy resin soften and destroy the polystyrene I am trying to
repair?
Is there a better way to repair these things?

I know it's polystyrene because it is marked PS.

Tim W



If I remember rightly the solvent for Polystyrene is Benzene, nasty
stuff.!!
Don
almost anything dissolves polystyrene, but that is the last thing you
want to to with EPS.

"Chris K" wrote in message
o.uk...
On 13/05/2011 12:15, Tim W wrote:
Briefly: Perfectly good Fridge freezer has lots of rubbish clear plastic
internal parts like this door shelf:
http://www.espares.co.uk/datastore/p...ges/831356.jpg
without which the whole thing is pretty much a chuck out.

Model is discontinued, parts are unavailable so I am repairing again.

Previously repaired some broken polystyrene parts by patching with
polystyrene from CD boxes and plumbers' solvent adhesive. These repairs
were
only partly successful, having lasted more than twelve months the
polystyrene has become crazed and crumbly and cracks are opening up
again.

I was proposing to repair this time with epoxy resin in conjunction with
wood stifeners, plastic patches or maybe glass mat.

Will epoxy resin soften and destroy the polystyrene I am trying to
repair?
Is there a better way to repair these things?

I know it's polystyrene because it is marked PS.

Tim W



Do you really mean epoxy or are you referring to the car body repair kit
stuff more widely available. The 'glass fibre' kits from Halfords etc are
largely stabilised styrene monomer that is persuaded to polymerise with
the hardner. This should bond well to polystyrene unlike the pipe solvent
adhesive.

I'd try using the same technique as you used before but using the car body
filler kits (without the powder filler).

CD case material is a bad choice as it is pure polystyrene and subject to
stress cracking and crazing. The polystyrene sheets available in the
sheds would be better. Glass fibre matting to add further strength would
probably help but look a bit of a mess..

HTH

Chris K


Thanks Chris. I have a small quantity of industrial type epoxy resin and
some glass tissue/mat (no filler/thickener) in the shed left over from some
wood/boat type work so I was going to use that, not polyester or any car
body kit.

Will the epoxy
i) bond well to the polystyrene, with or without abrasion or solvent
cleaning.?
ii) desastrously soften or dissolve the existing polystyrene.?

I know it's a fuss over a bit of plastic shelf but it takes some quite hard
use with teenagers in the house and if I can't mend it the fridge is barely
usable.

Tim W

"John Rumm" wrote in message
o.uk...
On 13/05/2011 12:59, Chris K wrote:
On 13/05/2011 12:15, Tim W wrote:
Briefly: Perfectly good Fridge freezer has lots of rubbish clear plastic
internal parts like this door shelf:
http://www.espares.co.uk/datastore/p...ges/831356.jpg
without which the whole thing is pretty much a chuck out.

Model is discontinued, parts are unavailable so I am repairing again.

Previously repaired some broken polystyrene parts by patching with
polystyrene from CD boxes and plumbers' solvent adhesive. These
repairs were
only partly successful, having lasted more than twelve months the
polystyrene has become crazed and crumbly and cracks are opening up
again.

I was proposing to repair this time with epoxy resin in conjunction with
wood stifeners, plastic patches or maybe glass mat.

Will epoxy resin soften and destroy the polystyrene I am trying to
repair?
Is there a better way to repair these things?

I know it's polystyrene because it is marked PS.

Tim W



Do you really mean epoxy or are you referring to the car body repair kit
stuff more widely available. The 'glass fibre' kits from Halfords etc
are largely stabilised styrene monomer that is persuaded to polymerise
with the hardner. This should bond well to polystyrene unlike the pipe
solvent adhesive.

I'd try using the same technique as you used before but using the car
body filler kits (without the powder filler).

CD case material is a bad choice as it is pure polystyrene and subject
to stress cracking and crazing. The polystyrene sheets available in the
sheds would be better. Glass fibre matting to add further strength would
probably help but look a bit of a mess..

Glass fibre tissue would probably be a better bet - like mat but a much
finer finish.


Thanks John what I have to hand is proper epoxy and some quite fine glass
tissue in fact not mat

Tim W

"The Natural Philosopher" wrote in message
...
Tim W wrote:
Briefly: Perfectly good Fridge freezer has lots of rubbish clear plastic
internal parts like this door shelf:
http://www.espares.co.uk/datastore/p...ges/831356.jpg
without which the whole thing is pretty much a chuck out.
[...]
Will epoxy resin soften and destroy the polystyrene I am trying to
repair?
Is there a better way to repair these things?

hot glue.

as a model aircraft buff, the fast ways to repair PS have all been tried.

PVA works, but takes ages to dry.
Epoxy works, but is bloody expensive
Odourless CA works, but its enormously expensive and wont fill gaps.
Ordinary CA will reduce styrene to mush.
some contact glues..thixofix? the latex ones that smell of ammonia work
pretty well. No gap fill
Hot glue works briliantly, and ripped apart models will be flying in
minutes. stronger than the plastic is, fills gaps and glue melting point
JUST below styrene melting point.


Hot glue. Excellent. I will try it. Thanks.

Tim W

Chris K wrote:
On 13/05/2011 12:15, Tim W wrote:
Briefly: Perfectly good Fridge freezer has lots of rubbish clear plastic
internal parts like this door shelf:
http://www.espares.co.uk/datastore/p...ges/831356.jpg
without which the whole thing is pretty much a chuck out.

Model is discontinued, parts are unavailable so I am repairing again.

Previously repaired some broken polystyrene parts by patching with
polystyrene from CD boxes and plumbers' solvent adhesive. These
repairs were
only partly successful, having lasted more than twelve months the
polystyrene has become crazed and crumbly and cracks are opening up
again.

I was proposing to repair this time with epoxy resin in conjunction with
wood stifeners, plastic patches or maybe glass mat.

Will epoxy resin soften and destroy the polystyrene I am trying to
repair?
Is there a better way to repair these things?

I know it's polystyrene because it is marked PS.

Tim W



Do you really mean epoxy or are you referring to the car body repair kit
stuff more widely available. The 'glass fibre' kits from Halfords etc
are largely stabilised styrene monomer that is persuaded to polymerise
with the hardner. This should bond well to polystyrene unlike the pipe
solvent adhesive.

no. It partially dissolves it.

Epoxy is inert.

I'd try using the same technique as you used before but using the car
body filler kits (without the powder filler).

CD case material is a bad choice as it is pure polystyrene and subject
to stress cracking and crazing. The polystyrene sheets available in the
sheds would be better. Glass fibre matting to add further strength
would probably help but look a bit of a mess..

butt glue cut blocks with hot glue. Its that simple.

shed 'white' polystyrene is better insulant that pink or blue extruded,
but any material works.

Cut with sharp knife and or sand 'gently'
small saw - tenon - also works.

HTH

Chris K

John Rumm wrote:
On 13/05/2011 12:59, Chris K wrote:
On 13/05/2011 12:15, Tim W wrote:
Briefly: Perfectly good Fridge freezer has lots of rubbish clear plastic
internal parts like this door shelf:
http://www.espares.co.uk/datastore/p...ges/831356.jpg
without which the whole thing is pretty much a chuck out.

Model is discontinued, parts are unavailable so I am repairing again.

Previously repaired some broken polystyrene parts by patching with
polystyrene from CD boxes and plumbers' solvent adhesive. These
repairs were
only partly successful, having lasted more than twelve months the
polystyrene has become crazed and crumbly and cracks are opening up
again.

I was proposing to repair this time with epoxy resin in conjunction with
wood stifeners, plastic patches or maybe glass mat.

Will epoxy resin soften and destroy the polystyrene I am trying to
repair?
Is there a better way to repair these things?

I know it's polystyrene because it is marked PS.

Tim W



Do you really mean epoxy or are you referring to the car body repair kit
stuff more widely available. The 'glass fibre' kits from Halfords etc
are largely stabilised styrene monomer that is persuaded to polymerise
with the hardner. This should bond well to polystyrene unlike the pipe
solvent adhesive.

I'd try using the same technique as you used before but using the car
body filler kits (without the powder filler).

CD case material is a bad choice as it is pure polystyrene and subject
to stress cracking and crazing. The polystyrene sheets available in the
sheds would be better. Glass fibre matting to add further strength would
probably help but look a bit of a mess..

Glass fibre tissue would probably be a better bet - like mat but a much
finer finish.


ultra light cloth is best of all.

Tim W wrote:
"Chris K" wrote in message
o.uk...
On 13/05/2011 12:15, Tim W wrote:
Briefly: Perfectly good Fridge freezer has lots of rubbish clear plastic
internal parts like this door shelf:
http://www.espares.co.uk/datastore/p...ges/831356.jpg
without which the whole thing is pretty much a chuck out.

Model is discontinued, parts are unavailable so I am repairing again.

Previously repaired some broken polystyrene parts by patching with
polystyrene from CD boxes and plumbers' solvent adhesive. These repairs
were
only partly successful, having lasted more than twelve months the
polystyrene has become crazed and crumbly and cracks are opening up
again.

I was proposing to repair this time with epoxy resin in conjunction with
wood stifeners, plastic patches or maybe glass mat.

Will epoxy resin soften and destroy the polystyrene I am trying to
repair?
Is there a better way to repair these things?

I know it's polystyrene because it is marked PS.

Tim W


Do you really mean epoxy or are you referring to the car body repair kit
stuff more widely available. The 'glass fibre' kits from Halfords etc are
largely stabilised styrene monomer that is persuaded to polymerise with
the hardner. This should bond well to polystyrene unlike the pipe solvent
adhesive.

I'd try using the same technique as you used before but using the car body
filler kits (without the powder filler).

CD case material is a bad choice as it is pure polystyrene and subject to
stress cracking and crazing. The polystyrene sheets available in the
sheds would be better. Glass fibre matting to add further strength would
probably help but look a bit of a mess..

HTH

Chris K


Thanks Chris. I have a small quantity of industrial type epoxy resin and
some glass tissue/mat (no filler/thickener) in the shed left over from some
wood/boat type work so I was going to use that, not polyester or any car
body kit.

Will the epoxy
i) bond well to the polystyrene, with or without abrasion or solvent
cleaning.?

not well, but well enough.

ii) desastrously soften or dissolve the existing polystyrene.?

No.

I know it's a fuss over a bit of plastic shelf but it takes some quite hard
use with teenagers in the house and if I can't mend it the fridge is barely
usable.


thiought this was EPS, not a shelf?

Tim W

"The Natural Philosopher" wrote in message
...
Tim W wrote:
"Chris K" wrote in message
o.uk...
On 13/05/2011 12:15, Tim W wrote:
Briefly: Perfectly good Fridge freezer has lots of rubbish clear
plastic
internal parts like this door shelf:
http://www.espares.co.uk/datastore/p...ges/831356.jpg
without which the whole thing is pretty much a chuck out.


Will the epoxy
i) bond well to the polystyrene, with or without abrasion or solvent
cleaning.?

not well, but well enough.

ii) desastrously soften or dissolve the existing polystyrene.?

No.

Thanks

I know it's a fuss over a bit of plastic shelf but it takes some quite
hard use with teenagers in the house and if I can't mend it the fridge is
barely usable.


thiought this was EPS, not a shelf?


Not EPS but Clear PS as above. Sorry for confusion. Now I think about it
the idea that hot glue could be the best repair should have set off the
alarms. No hot glue, epoxy it is. Thanks

Tim W

Tim W wrote:
"The Natural Philosopher" wrote in message
...
Tim W wrote:
"Chris K" wrote in message
o.uk...
On 13/05/2011 12:15, Tim W wrote:
Briefly: Perfectly good Fridge freezer has lots of rubbish clear
plastic
internal parts like this door shelf:
http://www.espares.co.uk/datastore/p...ges/831356.jpg
without which the whole thing is pretty much a chuck out.

Will the epoxy
i) bond well to the polystyrene, with or without abrasion or solvent
cleaning.?
not well, but well enough.

ii) desastrously soften or dissolve the existing polystyrene.?

No.

Thanks
I know it's a fuss over a bit of plastic shelf but it takes some quite
hard use with teenagers in the house and if I can't mend it the fridge is
barely usable.

thiought this was EPS, not a shelf?


Not EPS but Clear PS as above. Sorry for confusion. Now I think about it
the idea that hot glue could be the best repair should have set off the
alarms. No hot glue, epoxy it is. Thanks



For CLEAR styrene go and get plastic model kit cement from a model shop.

And ignore everything else I said.




Tim W

On 13/05/2011 14:40, Tim W wrote:
"Chris wrote in message
o.uk...
On 13/05/2011 12:15, Tim W wrote:
Briefly: Perfectly good Fridge freezer has lots of rubbish clear plastic
internal parts like this door shelf:
http://www.espares.co.uk/datastore/p...ges/831356.jpg
without which the whole thing is pretty much a chuck out.

Model is discontinued, parts are unavailable so I am repairing again.

Previously repaired some broken polystyrene parts by patching with
polystyrene from CD boxes and plumbers' solvent adhesive. These repairs
were
only partly successful, having lasted more than twelve months the
polystyrene has become crazed and crumbly and cracks are opening up
again.

I was proposing to repair this time with epoxy resin in conjunction with
wood stifeners, plastic patches or maybe glass mat.

Will epoxy resin soften and destroy the polystyrene I am trying to
repair?
Is there a better way to repair these things?

I know it's polystyrene because it is marked PS.

Tim W



Do you really mean epoxy or are you referring to the car body repair kit
stuff more widely available. The 'glass fibre' kits from Halfords etc are
largely stabilised styrene monomer that is persuaded to polymerise with
the hardner. This should bond well to polystyrene unlike the pipe solvent
adhesive.

I'd try using the same technique as you used before but using the car body
filler kits (without the powder filler).

CD case material is a bad choice as it is pure polystyrene and subject to
stress cracking and crazing. The polystyrene sheets available in the
sheds would be better. Glass fibre matting to add further strength would
probably help but look a bit of a mess..

HTH

Chris K


Thanks Chris. I have a small quantity of industrial type epoxy resin and
some glass tissue/mat (no filler/thickener) in the shed left over from some
wood/boat type work so I was going to use that, not polyester or any car
body kit.

Will the epoxy
i) bond well to the polystyrene, with or without abrasion or solvent
cleaning.?
ii) desastrously soften or dissolve the existing polystyrene.?

I know it's a fuss over a bit of plastic shelf but it takes some quite hard
use with teenagers in the house and if I can't mend it the fridge is barely
usable.

Tim W



If it really is epoxy, suspect not, particularly with temperature
cycling, but you never know.... I thought some boat resin work was PS
based. Does it smell strongly? Epoxies generally do not.

You really need something that dissolves PS to bond with it properly
like the old PS cements for Airfix models, that is before they changed
the solvent (Trichloroethane IIRC) to make glue sniffing unrewarding.
The current stuff does not seem to be anything like as effective.

The waste pipe cements are meant for use with uPVC pipe & will not work
well with PS.

Chris K

On Saturday, May 14, 2011 at 9:41:05 AM UTC+3, harry wrote:
On May 13, 12:15*pm, "Tim W" wrote:
Briefly: Perfectly good Fridge freezer has lots of rubbish clear plastic
internal parts like this door shelf:http://www.espares.co.uk/datastore/p...ges/831356.jpg
without which the whole thing is pretty much a chuck out.

Model is discontinued, parts are unavailable so I am repairing again.

Previously repaired some broken polystyrene parts by patching with
polystyrene from CD boxes and plumbers' solvent adhesive. These repairs were
only partly successful, having lasted more than twelve months the
polystyrene has become crazed and crumbly and cracks are opening up again.

I was proposing to repair this time with epoxy resin in conjunction with
wood stifeners, plastic patches or maybe glass mat.

Will epoxy resin soften and destroy the polystyrene I am trying to repair?
Is there a better way to repair these things?

I know it's polystyrene because it is marked PS.

Tim W

Whichever you do, drill the ends of any cracks to prevent propagation
before you start.

There are two types of GRP resins. Polyurethene based (the cheap
ones) and epoxy based ones (similar to Araldite) if that helps.

How about the solvent glue sold to glue ABS/PVC pipes? (No experience
of it in your situation.)

Solvent glue for PVC pipes works very well but only if it contains Tetrahydrofuran (see product's label), which a strong solvent for PS.

What you need is a 3D printer!
Brian

--
From the Sofa of Brian Gaff Reply address is active
wrote in message
...
On Saturday, May 14, 2011 at 9:41:05 AM UTC+3, harry wrote:
On May 13, 12:15 pm, "Tim W" wrote:
Briefly: Perfectly good Fridge freezer has lots of rubbish clear plastic
internal parts like this door
shelf:http://www.espares.co.uk/datastore/p...ges/831356.jpg
without which the whole thing is pretty much a chuck out.

Model is discontinued, parts are unavailable so I am repairing again.

Previously repaired some broken polystyrene parts by patching with
polystyrene from CD boxes and plumbers' solvent adhesive. These repairs
were
only partly successful, having lasted more than twelve months the
polystyrene has become crazed and crumbly and cracks are opening up
again.

I was proposing to repair this time with epoxy resin in conjunction with
wood stifeners, plastic patches or maybe glass mat.

Will epoxy resin soften and destroy the polystyrene I am trying to
repair?
Is there a better way to repair these things?

I know it's polystyrene because it is marked PS.

Tim W

Whichever you do, drill the ends of any cracks to prevent propagation
before you start.

There are two types of GRP resins. Polyurethene based (the cheap
ones) and epoxy based ones (similar to Araldite) if that helps.

How about the solvent glue sold to glue ABS/PVC pipes? (No experience
of it in your situation.)

Solvent glue for PVC pipes works very well but only if it contains
Tetrahydrofuran (see product's label), which a strong solvent for PS.