[mumofstig]

because the waterpipe my son acquired to make a polytunnel is 32mm diameter, which is exactly the same as the metal pipe I've just hammered in to the soil for the uprights 

Has anybody any suggestions for joining the 2 pipes together, now that I can't just slide the waterpipe over the top of the metal pipe

[AndyRVTR]

Hi MOS... what about some 32mm Philmac staight connectors... how many do you need??

[mumofstig]

I need 6, but how do they work/what are they like?

[Spana]

Wouldn't canes work

[mumofstig]

I had thought of that Spana, but I think that canes might break with the first strong
winds   

[8doubles]

The cheapest way will probably be to bang some smaller diameter steel tube inside the tube to make a spigot. 100mm in the metal and the same sticking out to go into the plastic pipe should do it.

[Spana]

Well if you dont think canes will be strong enough what about reinforcing rod that you put in concrete, cut to length.  You would need a fair bit inside top and bottom

[arugula]

Hi MOS... what about some 32mm Philmac staight connectors... how many do you need??

I need 6, but how do they work/what are they like?

Philmac and Plasson make fittings to attach MDPE to pipes made from a variety of different materials - websites for info or come and see me in store (or maybe not! ).

The cheapest way will probably be to bang some smaller diameter steel tube inside the tube to make a spigot. 100mm in the metal and the same sticking out to go into the plastic pipe should do it.

This idea seems good to me!

[mumofstig]

Mmmm...............thanks for the ideas...........the connectors look a tad expensive

I'll have a look to see what I've got for 'spigot' making ( an interesting new word to me ...........I think Jay would have fun with that one  )

[Lardman]

Whats the difference between the internal diameter of the pipe and external diameter of the metal rod ?

If its close id be tempted to heat the tube and flare it out (bucket of hot water might be enough) or you could cut a slit in the pipe just so it will give a few mm... so many low budget options 

[mumofstig]

My son did suggest cutting a slit so that the water piper would still go over the metal pipe, but I thought that the split in the plastic pipe may 'run' under the strain when it's windy

[hamstergbert]

Drill a small hole three to six inches up the pipe and then cut from that down to the end of the pipe - that will increase the resistance to the cut propogating further along the pipe. Fit onto the metal stubs with the drilled hole and slit on the inside facing side.  Strap round tight once in place - cable ties and a bit of grunt to get them really tightly fastened.

Additionally, best if you can warm the plastic up too before stretching it over the metal.

[Thrift]

Additionally, best if you can warm the plastic up too before stretching it over the metal.

That is exactly what I did when trying to fit a cap on a spare sewer pipe. I used a hot air paint stripper gun - probably a bit laborious but I bet it would work and give a really firm connection.

[8doubles]

If you do go for the spigot and the inserts are a bit slack you can hit them on the side to make them slightly oval in places and they will grip better.
To soften plastic pipe i always dip it in boiling water as hot air guns or blowlamps can be too hot and the pipe will concertina.

[Lardman]

Strap round tight once in place - cable ties and a bit of grunt to get them really tightly fastened.

Or even jubilee clips.