Holy thread revival

About to try this out, but have a few questions.

1.) To fill the legs what ration of glue / expanding foam are you using, and what products do you use ?

2.) Will something like unibond 'No more big gaps' be sufficient as i think it contains glue in it ?

3.) One more thing, found those monacor spikes but they have 'hammer-in' inserts, but surely doing this will cause the expanding foam to crack and or shatter because it's presumably brittle when hard ? Might be possible to hold the inserts in whilst the foam hardens, but il probably be trying to control its overflow going everywhere ?

cheers