If you don't mind losing the comments, you could do an RSS export from the /etc blog and an import into the other.
From the /etc blog, go to Option -> Reading. In the Syndication section, change the "Show the most recent" field to a large number (large enough to ideally get all posts).
Browse to that site's RSS feed and, from your browser, save it as an XML file.
Now, go to the other blog (the one you want to import into). Log in, click on Import, then click on RSS. Point it at that XML file you just created and let it fly.