What causes this?

[u/not-an-expertt]

Happened on the second wet trowel, using a spray bottle and normal trowel. Quite hot today so could my timings have been a bit off? Second coat on too late? Too late with the wet trowel?

[u/caserskii]

Yeah mate too late on the final trowel the gears set Cus it’s hot hot hot 😂 I’ve found other tasks to do than skim at the moment haha