Is it possible to "over-block" a membrane? - (Jan/28/2015 )

Most protocols suggest blocking at RT for 1 hour. But would leaving it a few hours longer cause anything detrimental to the final outcome of the Western?

it shouldn't, as long as your block is stable (no reason why it shouldn't be).

if you have concerns then you can block at 4C (usually overnight)

Yes I agree with mdfenko, we do at 4 degrees for overnight.

Wine, Whiskey and Western block, all improve with time.

sometimes wine sours

Wine is more like women, not all improve with age, but some do. Whiskey is more like men, all of them mellow with age.