Every post on here pays out exactly after a week. So if your post has paid out already then getting an upvote will make any difference as the post has paid out already.
So No! There is nothing like a second payout on the steem platform.
After seven days of the post the payout matures and paid to the author and curators. Any vote after 7 days of a post will neither consume voting power of the curator nor it will generate any monetary value in the post. So there is no question of a second payout. But one can still engage in that post, like commenting to a post even after 7 days. But there will be no monetary value, no payout after 7 days of the post. So in terms of monetization the post is like a dead rubber after 7 days.
No. The payout period has already expired.
Steem has a policy of a 7 day window for voting to occur. Once the 7 day window is closed there is nothing you can do.The vote is just lost
If you would like to reward on author of a post that has expired just look for a newer post or comment and upvote that way. You could comment letting them know that it was for the expired post.
The vote will be recorded in the blockchain but VP and payout~wise, nothing will happen!
There however is a service called Steem-Bounty Forever that allows one to reward posts that are already beyond payout (7 days+). All you need to do is replace the url link of your post from say steemit.com to steem-bounty.com or simply input the link here:: https://steem-bounty.com/services/forever
You will be asked to log-in on steem-bounty to cast your vote there. After you cast your vote, @steem-bounty will automatically create a comment redirecting your upvote there.
This works because Steem-Bounty makes the author of the said post the beneficiary of the comment payout. It is worth to note though that they take a little cut from it (Heh!) but it's a pretty cool way to reward an author's blog post from weeks or months ago :)