How to cap/seal a down-pipe

[d000hg]

I am thinking to use guttering downpipes for a project in the garden and I face the issue nowhere seems to sell end-plates for these to seal them. I don't know if they even exist... for normal guttering purposes it wouldn't be very useful!

Can anyone advise if such things do exist or if not, how I might make one? For preference I'll use square downpipe as I'll want to drill holes in it.

(My other thought was to use underground drain/soil pipe but it's a bit more heavy-duty than I might like)

 

[Burnerman]

I doubt if you would find the 'real thing' but how about plastic inserts for metal tube? I've used them up to 75mm square, and fixed them with hot glue or silicone. These things fit internally but 'end caps' are the male alternative.
John

 

[d000hg]

The other thing I realised is mini-flo guttering has 50mm downpipes, and you can also get 50mm waste pipes (for kitchens etc). I wonder how you might join them, because I can imagine both having useful parts for DIY projects.

 

[Burnerman]

I would imagine a 50mm compression coupling would exist, albeit somewhat clumsy! I'd doubt if the diameters would match exactly.
John

 

[Ian H]

What about glueing the male end of a rainwater pipe socket onto a cut piece of flat guttering?