Thread: Source for large flexible ducting?

I will be starting work on my workshop duct runs this weekend (while my clearvue is on the way). Ordered in the stormwater PVC and fittings I need from Total Eden (best price I could find). I will be going with the 150mm stormwater pipe to machines. I don't have it in my possession yet, but from what I have read it sounds like the outside diameter of this pipe is more like 160mm. Can anyone confirm this?

Given that I would be more inclined to use flex hose that attaches around the outside of the pipe with a clamp rather than using smaller diameter flex and stuffing it inside the pipe and attempting to seal with duct tape etc. I assume this means 160mm flex rather than the 150mm stuff - anyone with experience on what fits best?

So my main question - what is a good source (cheap, but sufficient quality flex) for the large flexible ducting?

* I have called Carbatec and they only carry up to the 150mm stuff.
* Felder carry it but are extremely expensive in comparison to the others.
* Blackwoods sell Eximo Polyflex in a light duty and regular duty version - the light duty is the cheapest price I have (still pricey) and the regular duty stuff is approaching Felder prices.

Anyone have experience with the light duty Polyflex? Is it suitable?

I find Blackwoods are usually overpriced on most things for a person off the street buying, so I am thinking there has to be a better source somewhere?