21mm overflow

[m-u-w_dick]

Does a plug exist for a 21 mm overflow pipe.

I have a pipe going into a rather complicated bonded waste outlet under the sink, but need to move the pipe and re route it lower down. If I cut it from the existing joint is it possible to plug the 21 mm pipe left out the back?

 

[gigz]

Cut it, dry out properly and fill with waterproof mastic