Looks like you got your question answered about the HELOC...
I have investors that get equity taken out of the house a few months after the close on the house and after repairs are finished. This is what I have them do: save up, get all of the repairs finished at once, reappraise, and get the HELOC. This all depends on the repairs you are doing. If it really is as you say "minor things" and its a light fixture here and a room painted there, those items wouldn't seem to move the appraised value much. However, if it needs a decent amount of fixing such as new siding and paint, new carpet/flooring, paint, bathroom or kitchen redone, etc. You will want to reappraise most likely. Also, the advise to go and get a 203K loan is not a bad idea either. There are more products like the 203K loan that are open to investors as well. Like Cynthia said, shop around and find the right fit.
This is all coming from my experience in Tulsa, OK while working with investors to get homes ready for renting and for the investor to get cash out of the house after repairs that where needed are finished.