Why is the "Edit Post" function locked out so quickly.. or even at all...

[Finnster]

Overall I think these forums are set up exceedingly well, but one thing has always bothered me. Why does the "edit post" function get removed after a few hours? I really hate this.
I like to update certain posts if I've made and error in info, or I've put more information in than I'd like forever archived, or if I've said something I would like to later take back (I imagine we all have if a good bashing thread starts up and we get carried away, and would rather go back and remove the fuel from teh fire...)

Most of all tho, is the ability to update build threads.. I hold off on build threads until I am nearly done as it gets so disorganized and less informative otherwise.
EG.: New post: Going to Convert XYZ.. ideas?
Replies: info, info, banter, banter, Linc's monkey butler stories, banter, banter,
Page 2: I made a batt box, here's pix: reply, banter, banter,
..Page 13: Its finally done, pics:

Personally I think its more helpful if I can update the OP w/ setup info, ET data, vids whatever, as well as have the stuff in replies, and have more room for BL blowup doll stories.
Esp helpful if you go searching thru other builds to find useful ideas, but have to sort thru 12 pages of nonsense just to find what you are looking for. If all the important updates could be in the OP, it helps everybody out. Or.. the setup you thought was great on Pg.1 blows up by Pg.3, a casual reader may not catch that info if they don't go digging.

Seems like it could help, and works well on a lot of other forums, and there has never really been a downside as far as I've ever seen.