bending plastic conduit - ?

[LukeScotty]

first thing comes to your head is, "use a bleeding bending spring"

Now, i was wondering as I havnt tried it yet,but has any one tried bending plastic conduit with a bending spring, on an actual bender tool thingi me bobs..... because I tried doing a double set in a length and it was quiet hard, to say i don't use it often. anyways, if anyone has any decent techniques, id love for you to share them, or whether you've tried a bending spring on a bender?

 

[Shakey]

Luke, i use a bending spring, but you got to warm up the conduit first to stop it creasing at the bend.

In a basic way, i just rub it between my hands (the conduit i mean!!!) where i am going to bend it, then bend it bit by bit, kepping warming it as you go.

you will need to bend it past the 90 degrees, then let it spring back to a perfect 90. Theres defintely an art to it.

I use whatever is around me. Done a job the other day and they had these heaters mounted on top of gas bottles - stuck the conduit in front of it for 30 seconds (turning it to heat up all the way around)

even stuck it on top of radiators before now.

use whatever you got, but your hands will work (just get a bit sore after a while)

 

[rumrunner]

Hi
like shakey says a bit of heat helps ,a double set is "not easy"i think i would end up cutting it in half and putting a coupling in ,biggest problem is getting the spring back out ,i presume you have tied it on a bit of cable ,if you want to bend it in a hilmor ,fill the pipe with sand ,never tried it but it works with thin aluminium pipe. good luck

 

[danzor]

bend it around your knee!

 

[wayne]

experience and the knee come to mind

also measure your bends,assuming we're talking about a saddle bend measure from the first bend to the second that distance wants to be same as third to fourth sounds easy but it never is

 

[rumrunner]

yeah i use the knee method ,but what luke was asking was if you can use a bender in conjunction with a spring ,i cant see why not ,but as i say ,its getting the spring out again!
atvbitwww

 

[wayne]

feel free to try a bender and be laughed at sorry!!
even when you bend steel conduit you can end up "tweaking" it to get it right trust me the plastic will end over the knee!

 

[LukeScotty]

lol, still doing it around the knee, not had chance to put it in the bender

 

[Cirrus]

Keep using your knee and keep practising. You'll get the hang of it

 

[Bane]

Around your neck

 

[Shakey]

yeah i use the knee method ,but what luke was asking was if you can use a bender in conjunction with a spring ,i cant see why not ,but as i say ,its getting the spring out again!
atvbitwww

now is that a british standard knee?

and i never have trouble getting the spring out

the missus always wonder where her fairy liquid is gone when i am doing plastic conduit....

 

[joe_berks]

i normally bend it over my knee , but i did try it in a hilmor and it was fine i would use a hilmor if there was one to hand. try it!

 

[devlin maguire]

Make life easy for yourself and use a hair dryer works great even in situ, and get a couple of formers in fact any thing with a radius can be used
Mac

 

[pennywise]

In the states they use really large diameter PVC conduit and duct, they use a heating case to make it more pliable, it like a hot box, there on the Internet look quite fancy. I usally use the spring around the knee jobby though, and I've just started to thread PVC as well never thought it would work but it does!

 

[Guest123]

The correct size spring and across the knee is the only way I've ever done it.

Just make sure the springs aren't mixed up i.e a heavy gauge spring in standard gauge conduit....thats when the kinks start to appear.

The ends of the springs are colour coded, red or green I think.

 

[Davey101]

Talk about raising the dead!

Not much point in using a bender for plastic, unless you have a lot of cables, or an FP etc, and need a slow bend. Nothing really wrong with using a bender, but the bends can end up looking a little large, wouldnt do it if its surface tube.

 

[Notsosmart]

Just make sure the springs aren't mixed up i.e a heavy gauge spring in standard gauge conduit....thats when the kinks start to appear.

The ends of the springs are colour coded, red or green I think.

I have attached colour coded singles, can get hairy pulling the spring out of a double set near the middle of a length though!

 

[Guest123]

I know what you mean.....I usually stand on the wire attached to the end of the spring and pull it out that way. When it gives up and shoots out at least then it only smashes into your steelie rather than smashing the bones in your fingers!!!!!!!!

 

[Notsosmart]

Yeh you only use your hands a couple of times before you learn that lesson

 

[lewlec]

The correct size spring and across the knee is the only way I've ever done it.

Just make sure the springs aren't mixed up i.e a heavy gauge spring in standard gauge conduit....thats when the kinks start to appear.

The ends of the springs are colour coded, red or green I think.

hi lenny

thanks for that, i wasnt aware of the different colours on the springs.. that explains the cursing of my new spring a few weeks ago!!!

regards
gary

 

[Guest123]

Extract from Centaur manufacturing....


"

Conduit Bending Springs
CHS 16 Heavy Gauge, Green 16mm 1
CHS 20 Heavy Gauge, Green 20mm 1
CHS 25 Heavy Gauge, Green 25mm 1
CHS 32 Heavy Gauge, Green 32mm 1
CLS 16 Light Gauge, Red 16mm 1
CLS 20 Light Gauge, Red 20mm 1
CLS 25 Light Gauge, Red 25mm 1​

CLS 32 Light Gauge, Red 32mm 1"


So heavy gauge - Green, and light gauge = Red.

 

[frecossais]

I worked in France for 7 years and found that I could bend PVC conduit no bother on my knee or between my arms no bother albeit with a bending spring but when I came back to Scotland to live the first time I tried it I kept putting kinks in it!! Then i seemed to remember that there are two different gauges here! Am I dreaming this or is it true? Can someone let me know as it's a long time since I have done domestic work here as before I went to France I was working in street lighting for 7 years

 

[Notsosmart]

See Lenny's post above Frecossais.

 

[frecossais]

In France though it's so easy. No need to worry about light or heavy gauge it's all the same standard. i think it's all geared to heavy gauge as then it all errs on the side of caution. I think!!

 

[gaffer]

All the wholesalers around here seem to only stock HG.

 

[lj.l]

when I started in the training center we put the former in the vice and used a spring,never seen a vice out on site though so its always been the knee

 

[wattsup]

On the knee! Practice first.
Make sure the conduit is warmish, like others say...double sets/dog legs are the hardest.....getting the spring out, knocks the set out sometimes.

But, the tip is, lubricate the spring with cooking oil then it pulls out easy...makes a bit of a mess so have wrags handy.

 

[Davey101]

Never thought of lubricating it before.
If the spring is tight to get out of the bend, just put the bend on the ground with the spring pointing up towards your head, foot on the bend, then pull on the spring and 'tap' the bend on the ground, letting your foot 'bounce' the conduit on the ground. Alternatively, pull the spring and bang the tube on the ground, stack of plasterboard etc. The key is to bounce or tap the spring on something, rather than just pulling as hard as you can.

 

[Bromd123]

I was taught that all you need is your knee a bending spring and a bit of grease........ of the elbow variety lol

 

[pennywise]

PVC bending taken to a new level


Greenlee Products - Greenlee A Textron Company

 

[Greenriff]

Bend it round your knee with a spring inside, but make sure you dont make the radius of the bent too small. There is a skill to learn here, you dont need to rub/heat/warm the conduit if you bend it properly. Refer to the regs to find out the minimum bend radius. Start to bend the conduit at a certain point using your knee, 1st bend it slightly, 2nd bend it slightly again at another spot about 20mm away from the first bend, keep bending it more and more alternating between each point until you get a smooth radius started then you can just bend it all the way using your arms only, 3rd bend it too far then unbend it to the angle required. shazam it should stay there. You need to practise this lots to learn the skill so you dont end up with a tight right angle with stress marks which is hard to pull cables into(I see these bends all over the place).

 

[Ashley Williams]

Heat and around your knee. Get a paper cloth and rub it creates enough heat but saves your hands.. The conduit...

A

 

[Johno]

***** to the radius, as long as it looks right and the cables aren't to tight. (just being honest)

 

[benji]

no disrespect to anybody but i never thought a thread on bending plastic conduit would go on this long,
IT,S JUST PRACTICE thats all.


yours benji

 

[gaffer]

no disresect to anybody but i never thought a thread on bending plastic conduit would go on this long,
IT,S JUST PRACTICE thats all.


yours benji

Everyones got to learn

 

[Scott F]

Whats the different applications for light and heavy gauge plastic conduit ?

 

[UNG]

Tallow on the spring helps when removing from the conduit and not as messy as oil

A rag to rub the conduit to get heat in it is how I do it can take a few attemps to get a bend depending on the ambient temp. If it's possibe leave it somewhere warm for a few hours before using it

 

[Cobraman]

I just rub the conduit a bit with a dry tea towel, put the bending spring in and bend, thats all there is to it and have had no problems with this method.

 

[Davey101]

No offence to anyone, but unless you have some crappy quality tube, there is no need to rub or warm the conduit (dunno about light gauge, does anyone actually use this?).

 

[YTSOxford]

Leave it on one of a work light for a few seconds and bend with a spring in it. Don't go off for a tea break tho, or you'll be cleaning your light!

 

[UNG]

No offence to anyone, but unless you have some crappy quality tube, there is no need to rub or warm the conduit (dunno about light gauge, does anyone actually use this?).

It would be interesting to know what tube you are using from your comment. I have used tube from most manufacturers and unless it is in a warm environment it all needs warming to bend it without problems

 

[Sintra]

Always needs warming. Never seen any make of tube that would bend properly cold.

 

[bugsy]

Ive never bent pvc conduit without getting a bit of heat into it regardless of quality

 

[Phil]

first time i bent it turned into a right mess. think i even managed to split the sides of it, my mates sides were splitting too when he seen it

 

[Davey101]

Not sure on the make of tube to be honest, most of it either comes from Newey's, or Edmunsons.
Have just been working on a hospital with several thousand metres of tube in it (around 40 sparks), cant comment on all the sparks on site, but none of my mates warmed it up, and we had no problems until we had a bad batch/different make, which was constantly cracking, or creasing. I've got 3 bundles on my site now, none of us warm it up, and I had frost on my van this morning.

Not saying that you will never have to warm it, just that I haven't seen anyone do it since my apprenticeship.
Perhaps its the difference between light and heavy gauge?

 

[Matt!8]

I was doing a lot of work with 20mm conduit and just a bending spring then bending it by hand and it worked well. However I bought 25mm conduit and a 25mm spring and I can not get it to bend without kinking, the spring seems to be too loose but I have bought springs for both heavy and light wall conduit. Does anyone know what I’m doing wrong to get the conduit bent without wrinkles or kinks?

 

[littlespark]

I was doing a lot of work with 20mm conduit and just a bending spring then bending it by hand and it worked well. However I bought 25mm conduit and a 25mm spring and I can not get it to bend without kinking, the spring seems to be too loose but I have bought springs for both heavy and light wall conduit. Does anyone know what I’m doing wrong to get the conduit bent without wrinkles or kinks?

It’s maybe mentioned already in this 10 plus year old thread that different conduit manufacturers have slightly different interneal diameters, so you need to get the spring for the same stuff.

Not just light or heavy duty… Marshall Tufflex will be different to EGA for example

I was always taught to rub vigorously beforehand.

 

[Julie.]

...
I was always taught to rub vigorously beforehand.

I try to use some external heat, space heater, hot air gun etc.

The rubbing thing is not a movement I am particularly familiar with.

 

[Matt!8]

It’s maybe mentioned already in this 10 plus year old thread that different conduit manufacturers have slightly different interneal diameters, so you need to get the spring for the same stuff.

Not just light or heavy duty… Marshall Tufflex will be different to EGA for example

I was always taught to rub vigorously beforehand.

Thank you