Learn me: Retapping oil pan drains

I have two vehicles leaking oil from the drain plug. Both have stripped, or at least slightly stripped oil drains. I want to retap both of them so I don't have to keep replacing the cardboard underneath them. (Note: Neither of them are leaking bad enough for it to even register on the dipstick after 3k miles)

I've never retapped anything other than a keg, which somehow I don't think applies here. What tools do I need? Will Harbor Freight suffice, or is there better quality for not much more money? How do I do it? Any other recommendations? 

For now, a single oversize plug and new gasket. That should fix it.   Wait until you're really screwed to remove the pan and retap.  

Any good auto parts store will get you an oversize plug.

Are your existing threads a tapered thread? Straight thread with a flange and sealing washer? Straight threads with an internal seat?

All this is critical before we can offer advice

Aluminum or tin oil pan?  Aluminum can be tapped, tin maybe.  

Before you ruin your pans with garbage oversized plugs, go buy a new plug and gasket in the stock size.  I have seen many, many drain plugs with stretched threads, and a new plug fixes all the trouble.

Jb weld, chicken fat, syrup, gas station nacho cheese. These are just a few ideas that came immediately into my mind. 

I re-tapped the pan on my Honda rally car. I bought a new plug and gasket and it was still borked. Pulled the pan, cleaned it out, tapped it and put a helicoil in it.  Cleaned any shavings out, reinstalled and put the new plug and gasket in.

Doesn't leak a drop.

depends on the pan material and how bad it is. Ill run a grease coated tap in too chase threads and try a new plug before it gets worse. Oversized plugs are a stop gap and if you do your own oil changes you will hate it almost everytime you have to take it out. if your going to pull it all apart to helicoil sometimes its more sensible to just buy a new pan. volkswagon oil pans are satan.

I used one of the oversized rubber expansion plugs.  About $5-6 @ any autoparts stores.  Admittedly suggested for temporary fix but the one I used hasn't leaked a drop on challenge car and buys time until I want to tackle removing pan and retapping.

Ovid_and_Flem said:

I used one of the oversized rubber expansion plugs.  About $5-6 @ any autoparts stores.  Admittedly suggested for temporary fix but the one I used hasn't leaked a drop on challenge car and buys time until I want to tackle removing pan and retapping.

i also used a rubber expansion plug when i found the drain plug for my 3 wheeler to be totally stripped and it worked flawlessly.

Sorry for the slow responses. 1996 Miata and 2004  Tribute. The Tribute has an expansion plug in it now; it leaks a lot. The Miata's was seized, and I had to get a bolt extractor to get it out. The new plug went in fine for the first 3/4 of the way, then I had to use some force. I'm assuming I'll have a similar experience next time getting it off; in any case it leaks about a drop a day--that one I'm more concerned about just because I don't want to keep buying new plug nuts, which I am anticipating.