Use of epoxy for levelling

[routercnc]

I've only done this a few times (3 in fact, 1st time was not so good, 2nd and 3rd went OK !) and used exactly that epoxy mix. I think what has happened in your case is if a lot of mixture is altogether in one pot then the heat from the parts of the mix in the middle cannot escape so it heats up. This promotes rapid onset of the curing of the rest of the mixture which releases more heat in a runaway reaction. I'm sure they mention somewhere not to mix large quantities in compact containers.

I think you will get ~72 hours when it is all spread out in your moats, so in my view it needs to be mixed and poured straight away. I didn't see much escaping of bubbles after the stirring when I did it as it is such as dense mix, so I don't think waiting helps (is my limited experience).

I only mixed about half that amount in a relatively wide plastic jug, alternating between 105 and 209 and think I only stirred at the end, slowly to avoid incorporating more bubbles. Then I did what others had suggested (Clive?) - the "2 jugs" method.

The fresh mixed is carefully poured into a second jug, which seems to promote some of the bubbles to be released, possibly because in the thin stream that pours from one jug to the other they are forced to the surface.
This second jug has a ~5mm hole towards the bottom of one side covered with tape and once all the mix has been transferred across you hold the jug over the machine, release the tape, and this will pour out into the moat. Again this seems to prevent too many bubbles getting into the moat.

Leave a small amount in the jug as this will be very aerated.

Here was my second attempt on the X axis:
https://www.youtube.com/watch?v=FDrcpnVUcEE

And using this method on the Y axis:
https://www.youtube.com/watch?v=aw0pM_uV1kw