Best way to bend 25mm PVC conduit?

[haggis999]

From time to time, I have a need to put a fairly gentle bend into 25mm PVC conduit. Past attempts to do this using nothing but a bending spring (originally bought for 22mm copper pipe) were not successful. I found that I could do the job if I warmed up the conduit with a heat gun, but have never been totally happy with the results, as the PVC develops obvious ripples at the heating points.

A few days ago, a member of staff at my local WF Senate told me that I shouldn't have to use a heat gun, so I've just tried again. The results were the same as before, i.e. the conduit simply springs back to the straight position after I bend it.

Is there a knack to this bending process or do I just need to put more effort into the bending? Do I perhaps need a better spring or different conduit (I use MK Heavy Duty 25mm round conduit)?

 

[Risteard]

As I posted here two days ago, I bought a new MK-branded 25mm bending spring that solved my problem with bending MK heavy duty conduit. The spring packaging did not state if it was intended for thick-walled tubing, but it did the job.

They are colour-coded for heavy gauge and light gauge. (Red and green.)

 

[dsmilne]

The best way I have found is using a spring on an open flame eg cooker.

Gently rotate with one hand either side over the flame and when ready to bend, stretch the conduit and bend. That should take out the ripples.

Be prepared for trial and error. I usually make right angles, but have done other angles as well as combinations, again trial and error.

 

[haggis999]

They are colour-coded for heavy gauge and light gauge. (Red and green.)

That's interesting. I was wondering why my spring has a red marking!

The best way I have found is using a spring on an open flame eg cooker.

On the few occasions in the past when I have needed to bend conduit, I used a hand-held heat gun, but never got good results, as I always overheated the pipe. This was probably because I couldn't bend the pipe at the same time as heating it and thus never knew when to stop the heating. Your method sounds more controllable.

Not being in the first flush of youth, I don't have the strength to bend unheated conduit over my knee. My recent success with a new spring was done with one end of the conduit clamped in an ancient Black & Decker Workmate. Next time the need arises, I will see if our gas cooker can help me dispense with the Workmate.