Repairs to Polystyrene fridge Parts
Tim W
internal parts like this door shelf:
http://www.espares.co.uk/datastore/productimages/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
Donwill
Don
Chris K
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
John Rumm
Glass fibre tissue would probably be a better bet - like mat but a much
finer finish.
--
Cheers,
John.
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The Natural Philosopher
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.
The Natural Philosopher
want to to with EPS.
Tim W
"Chris K" <neb...@nowhere.com> wrote in message
news:14CdnXvDboWVgFDQ...@brightview.co.uk...
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
Tim W
"John Rumm" <see.my.s...@nowhere.null> wrote in message
news:GPSdnRIAe5m0t1DQ...@brightview.co.uk...
Thanks John what I have to hand is proper epoxy and some quite fine glass
tissue in fact not mat
Tim W
Tim W
"The Natural Philosopher" <t...@invalid.invalid> wrote in message
news:iqjcbj$jfn$1...@news.albasani.net...
> 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/productimages/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
The Natural Philosopher
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
The Natural Philosopher
The Natural Philosopher
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
>
>
Tim W
"The Natural Philosopher" <t...@invalid.invalid> wrote in message
> Tim W wrote:
>> "Chris K" <neb...@nowhere.com> wrote in message
>> news:14CdnXvDboWVgFDQ...@brightview.co.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/productimages/831356.jpg
>>>> without which the whole thing is pretty much a chuck out.
>>>>
>>
>> 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
The Natural Philosopher
For CLEAR styrene go and get plastic model kit cement from a model shop.
And ignore everything else I said.
> Tim W
>
>
Chris K
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
harry
> Briefly: Perfectly good Fridge freezer has lots of rubbish clear plastic
> internal parts like this door shelf:http://www.espares.co.uk/datastore/productimages/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.)
medd...@gmail.com
Brian-Gaff
Brian
--
From the Sofa of Brian Gaff Reply address is active
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