Brassica cage or poly tunnel

[lottie dolly]

I have an old metal frame,MR extended it by a few feet a few years ago,it was the lottie fruit cage,however,it is now at home,and i machined netting together,to use as a brassica cage,BUT,i miss my polytunnel,and are thinking about taking the net off,and turning it into a poly,the problem i have is with the frame it's self,as in,what to put over the metal pria to the cover,as it will cost a fortune in anti hot spot tape,i was wondering about cutting up some foam sheeting and tapeing on,as the cover WILL touch most of the frame,the 8 bars that go from back to front cannot be removed,as would collaps,one thing for sure is,it will not blow away,i will have to form a door each end ext,the size is aprox,18fx8f,as the metal is aprox 2.75 of an inch wide,it does get hot,it also needs to be something smoothish,another idea is,i have to much debie netting and wondered if it would keep the direct heat of the cover,if it was used to wrape round the frame like a lagging,so as not to chaff on the foam or what ever is used,i aim to get a decent cover,it should see me out the gardening stage hehehehe,here is some picks,
What do you think,and have you any other ideas please.

[veggiechicken]

Foam Pipe insulation - like this?

https://www.screwfix.com/p/economy-p...3mm-x-1m/72357

[lottie dolly]

I have looked at that,but the usuall pipe side is far to small,and the larger diameter is expensive,for the amount i would need,aprox 18 ft x 13 lenths