Bending perspex/plastic
Ben C
I want to buy a clear strip of thick plastic/perspex, roughly 10cm wide and
165cm long and I want it bent at 90 degrees down the middle along its entire
length. I have heard that I can find this in B&Q, don't know who could bend
it for me. Do B&Q/Homebase etc do something like this? Any ideas what
other shops might be able to supply and/or bend the plastic for me? For
specific shop recommendations, I'm in London but can travel reasonable
distances to find it.
Thanks for any tips you can offer...
Cheers,
Ben
Paul Hewish
You don't say how thick the Perspex is; this may have an impact on the
bending method. Say under 10mm thick you can use a line bender (sometimes
referred to as a strip heater) - the Perspex is heated along the 'bend line'
& then bent around a jig or former to the correct angle, held in place to
cool. Thicker than 10mm then use an oven (a domestic oven on low heat will
work but do a test piece first) to heat the Perspex - the problem with this
method is that the whole of the sheet becomes floppy and therefore difficult
to handle. Both methods require the jig/former to have a smooth surface
otherwise imperfections will be transferred onto Perspex. Where to access a
line bender? Your local secondary school (Technology Dept) will have one
and I'm sure they would be more than willing to help you with a job that'll
only take 10 minutes. Trouble is you'll have to wait 'till beginning of
September when they come back from their hols.
Best of luck
Paul
"Ben C" <sp...@spam.com> wrote in message
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Gnube
<paul....@ntlworld.com> wrote:
>Thicker than 10mm then use an oven (a domestic oven on low heat will
>work but do a test piece first) to heat the Perspex
I suspect at 165cm in length, it is going to be fun finding an oven to
use for this approach!
Take Care,
Gnube
{too thick for linux}
Grunff
> I want to buy a clear strip of thick plastic/perspex, roughly 10cm wide and
> 165cm long and I want it bent at 90 degrees down the middle along its entire
> length. I have heard that I can find this in B&Q, don't know who could bend
> it for me. Do B&Q/Homebase etc do something like this? Any ideas what
> other shops might be able to supply and/or bend the plastic for me? For
> specific shop recommendations, I'm in London but can travel reasonable
> distances to find it.
Got a hot air gun? If not, pick one up (£15). Support the
perspex, and position the air gun underneath, about a foot away.
Set it on low setting, and wait. In about 10 minutes, it'll be
soft enough to bend. Bend it over a former of some sort (table
top works well).
--
Grunff
tony sayer
writes
and plastics in cherryhinton high st.
They seem to have every plastic that's in use and seemingly do all
manner of things with it. Bending u can do at home with differing
degrees of success and heat!, but there are machines which they have
which make a very good job of this sort of thing...
Course they have a website and here it is,
http://www.edplastics.co.uk/
--
Tony Sayer
Andrew McKay
>I want to buy a clear strip of thick plastic/perspex, roughly 10cm wide and
>165cm long and I want it bent at 90 degrees down the middle along its entire
>length. I have heard that I can find this in B&Q, don't know who could bend
>it for me. Do B&Q/Homebase etc do something like this? Any ideas what
>other shops might be able to supply and/or bend the plastic for me? For
>specific shop recommendations, I'm in London but can travel reasonable
>distances to find it.
When I was young (teenager) I managed to successfully bend a piece of
perspex to make a new lid for my record player. I clamped it between
two pieces of wood then poured boiling water over the section I wanted
to bend - it worked quite well.
However I suspect that I was lucky to be using perspex which had a low
enough melting point.
Andrew
Do you need a handyman service? Check out our
web site at http://www.handymac.co.uk
Richard Pawlowski
as the most commonly available strip heaters are a metre long max. Likewise
hot air guns are only useful on short lengths as the acrylic will cool as
you heat up other sections you need to heat the acrylic up to a temp. of
125C to 135C depending on the acrylic.
To be honest the only solution is to build your own strip heater or heating
oven. The strip heater can be built using electric fire elements, the glass
tube type with element wire inside. This is what most commercial ones use.
You will have to build a base from heat proof material with a groove in
which to lay the element the name of the stuff eludes me at the moment. of
course all the wiring will have to be heat proof too and you will be working
with mains electric so building it will pose several problems regarding
insulating the connections.
A heating oven sounds complex but might be a simpler solution as the heat
could be provided by a string of heating bulbs similar to the type used in
restaurants to keep food on display hot. These could simply mounted on a
batten above the acrylic which again would have to be placed on heatproof
material and all you need do to create an oven is to surround the heating
area with fire bricks preferably but ordinary ones will do as there function
is to contain the heat within the heating area.
The bending mould would simply be two pieces of wood at the required angle
with a stop on one for lining up purposes. lining the mould with felt should
ensure a scratch free finish. If you use the oven method then all the
acrylic will soften then you will need a nother felt lined batten to push
the acrylic into the mould and hold it there till the temp drops and the
acrylic becomes rigid
Good luck
Richard
"Ben C" <sp...@spam.com> wrote in message
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Ben C
think I'm going to look for a long plastic/perspex tube and cut a quarter
section out of it instead. This should give me the same end solution,
although it's obviously dependent on successfully finding the tube in the
first place! Trying to build my own extra long heater etc just for this
one-off job is just as hard as my original problem, and probably worthy of a
message thread in itself...
Cheers for all the advice. Maybe I'll move to Cambridge!
Ben
"Ben C" <sp...@spam.com> wrote in message
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Paul Hewish
kit not big enough for Ben's task but some schools (& colleges) do have
larger line benders (up to 3m) so it's probably still worth him ringing
around. Failing that I think your solution for a 'home-made' bender is
basically sound but he should avoid 240v route and electric fire kit (for
safety!).
The original line benders used Inconel heating elements (the glass tube kit
you mention) but this has now been largly replaced by the single (sometimes
2) wire method.
Ben would need to fabricate a frame longer than his piece of acrylic sheet,
this could be 2 strips of timber (maybe 12mm thick) fixed with cross pieces
at each end so there is a gap of, say 8mm between the long bits; this frame
is backed with kitchen foil (reflector). Suspended in this 8 x 12 groove
would be a length of 20 swg NiChrome wire fixed at the ends by terminal
blocks. A suitable low voltage around the 12v mark (some proprietary kit
uses 2 low-vo settings of 14.1v & 11.8v)
- maybe a car battery charger of the older variety 'cos they haven't got
cut-outs like some of the newer ones. This should
give Ben a suitably glowing hot wire with which to heat his acrylic (he
could add a 2nd wire, not touching the first!, for extra heat if he wants to
bend thick stuff). His sheet would have to be placed above the heater,
maybe even on spacers to allow some degree of temp control. The ideal
thermoforming range for acrylic is 145C to 170C, above this higher limit the
physical properties of the material will be impaired by 'crease',
'blistering', 'spread & stretch'. If care is taken sharp bends can be
achieved with this type of home-made kit.
Paul
"Richard Pawlowski" <richard....@ntlworld.com> wrote in message
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Paul Hewish
posted a 'how to' guide for you elsewhere) then acrylic tube is readily
available in lots of common diameters, from 6mmO/D(4mmI/D) up to
100mmO/D(94mmI/D), and even bigger if you want (& in colours even
fluorescent!). Have you thought of fabricating your 'bend' from 2 strips
of acrylic by bonding with a solvent adhesive (Tensol No12 or Tensol No70) -
you'll not see the join if proper care is taken. All this stuff can be got
(ask for their catalogue) from K&M's, in Sheffield, tel: 0114 247 4733
You don't say what you are trying to make - post it as there may be
alternatives.
Paul
"Ben C" <sp...@spam.com> wrote in message
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Ben C
> You don't say what you are trying to make - post it as there may be
> alternatives.
Well, it's a bit weird, but bear with me:
I have changed the layout of my bathroom and the bathtub is now underneath a
sash window, with the top edge of the bath touching the window sill. I
belatedly realised that the wall-mounted shower will constantly drench the
window and right-hand side of the window frame. Although I have painted the
frame and put sealant around the edges, I'm sure it won't survive being
blasted with hot shower water every day. So to protect it, I have found a
latex roller blind to put over the whole frame and window (this lets light
through, but not shower water). Although this protects most of the window,
I still need to protect the right hand edge of the window frame as the blind
will not cover this and it's directly in the path of the shower.
If I put a right-angled/curved strip of perspex on the edge of the window
frame, the latex blind will fit snugly behind it, and water should be unable
to reach the frame.
Hope this makes sense! Any other ideas? Perhaps I'm overcomplicating
things...
Bob Minchin
Get polycarbonate plastic sheet - one brand is Makrolon (sp?). Polycarbonate
can be worked cold with normal sheet metal machines and stays reasonably true
optically.
Bob
Paul Hewish
doesn't cover? If it's small why not use channelling, either in coloured
plastic or, and this would be my choice, annodised aluminium - also
available in colours and different dimensions. How to fix to the window
frame? Well I suppose you could drill & screw - the prob here would be the
screw heads showing and the blind fouling on the screw shanks inside the
channel. You could drill 'keyholes' in the channel's back surface then drop
it onto the screws (maybe round heads so as to minimise blind fouling)
already fixed into the window frame; there would be no screw shanks crossing
the channel. Or you could use an adhesive, something like Gripfill.
Scratch the back of the channel for a good key for the adhesive.news:bh8laa$dbm$1...@news6.svr.pol.co.uk...