[mrjonathanr]

Or could you reverse build them to your board? Sort out the volume base/ fixings to fit your existing T nuts, then build the volume onto that with a panel on it you screw/unscrew to reach the bolts…

[Paul B]

Cut a square hole in the board (with a multi tool), feed a rectangular bit of wood with a t-nut in it through the hole and secure it either side. Replace the square with a mildly oversized hole  to make things flush and use with a long bolt to secure whatever.

Alternatively overlay with plywood pre drilled and t-nutted and drill through the original plywood so the bolt has somewhere to go. This would probably need marking, drilling and then refitting.

[User deactivated.]

I like the sound of the plywood pattress with T-nut. Seems straightforward, cheap and effective.

I don't have any T-nuts on my board currently otherwise I would have just built volumes around them. I'm not sure a French cleat would give enough lateral stability.

[Probes]

Ive seen something similar with the french cleats. You could try having a couple of additional cleats spun 90 deg, spun opposite to each other, this would stop any sideways movement. It would take some giggery pokery to get them lined up.
Failing that could you slap a couple of bits of 2x2, fixed to the board, with a 10mm hole through at 90 deg. And fix tnut to volume and m10 bolt through 2x2 into tnut in volume. Done on both side of volume it would hold it. Not pretty.

[SamT]

Who's going to fess up then 

https://www.facebook.com/share/r/icpbnFZqan4y98X9/

[webbo]

That page isn’t loading.

[kac]

If anyone is still wondering when lonestar washers will be available you can now get filth nuggets from climbing wall services. They seem to do the job really well so would recommend.