You will probably have to add a bit more thinner around the middle of the process as some will evaporate out while the jar is open.
(You; to add; a bit more thinner; T:around the middle of the process) (some; will evaporate out; T:while the jar is open) (the jar; is; open)
You some the jar
to add will evaporate out is
a bit more thinner T:around the middle of the process
T:while the jar is open
open