Which ply to use external

[SFK]

composites for example each board will be £££s

Yes - I have been lucky and got used boards locally at okay prices often less than ply):
https://www.ebay.co.uk/sch/i.html?_...stomid=&toolid=10001&rt=nc&LH_ItemCondition=4

 

[Deleted member 174758]

Super strong, and v light. But do get dints in them relatively easily.

Yes, but Dibond-type sheets still need to be carried on a framework and cost about 4 to 5 times what Foamalux costs and damage more easily, so I fail to see any advantage. I also think 3mm would be as much use as a chocolate teapot in this instance (they'll get bent to hell in next to no time) - surely you'd need to try something like 8 to 12mm

 

[catlad]

You could try taping the edges with some 2" pvc tape

 

[freddiemercurystwin]

Or coat the ply in GRP, job done.

 

[catlad]

What exactly is a tennis wall anyway?

 

[SFK]

It's a wall you hit the tennis ball against so you can practice against yourself.

Think table tennis when you have half the table upright.

SFK