tried this last sunday.the flake has a lot of movement.if it gets any ice forming behind it next winter it would be curtains for it i think.i say do it but make a good job.im sure you would anyway.
I walked past ya I think, there were a good group of you trying it?? Anyone do it, looked like one of ya were getting very close.
As for stopping it breaking off, the only long term solution is to break it off pre-emptively, clean all the dirt and woodlice off the back and stick it back on again with a good quality gun resin. If done carefully this will give a permanent and near invisible repair, if done badly it may fuck the problem royally! I dare say some people might object to this approach, it's a tricky subject. I have done this sort of fix on limestone sport routes and one limestone boulder prob, but have thankfully never had to consider it on sandstone/grit. You could put a bead of resin around the back but this will only last a few years and is pretty unsightly, especially if you put on a big enough bead to last. Pouring glue into the crack is totally ineffective IMO.
you're calling yourself rainbow. how much more of a dick can you look?
I remember that Garry Wickham or Southern Sandstone fame painted up the rock with some stuff. I'm sure Jasper or Ben P will be along with the details and a boring recollection of some of the most underrated choss in the country etc etc