Where to find disc?

I am wanting to build a disc to pull behind my ATV, we have the welding and fab skills to make it work I am just having a hard time finding a disc/harrow to start off with? Looking for something that is free or cheap. It doesnt have to look good just need something to start with. Any suggestions where to find such a thing?

If you know any farmers with large harrows you could use discs from those after they are worn down some. I have a 6' harrow that has about 18" discs and I have used those from a larger harrow for years. I think these were 24' or larger to start with.
I've built ATV harrows before and I used new 16' discs from Agri-supply. They aren't very expensive.

If you are looking for parts to build one; Agri-supply will have what you need. ( www.agrisupply.com )

If you are looking for a disc harrow unit that is already constructed & intend to modify it to use behind an ATV, I'd look for a "bush & bog" harrow on craig's list or in the GA Market Bulletin: what most people advertise as the above is a single section disc harrow with 2 gangs side by side, with a tray above them you can add weight to:

http://www.google.com/search?q=bush...ASQ04CoDg&sqi=2&ved=0CFEQsAQ&biw=1024&bih=571

That is the model that they designed commercial ATV harrows off of. You'd need a way to raise & lower it with wheels, since you'll lack a 3ph.

There is also one for sale in the swap-&-sell on here, as well as a commercial ATV harrow. Don't think you're gonna find anything for free; even the steel is worth something, even if it's rusted stuck.

Agri-supply, The first time I went, I was there 3 hours just looking around

Agri-supply has the disc for about $7 each. I have 8 disc on my homemade set of harrows. You can look at store bought sets just for an idea of how you want to construct yours.
There are several sets on Craigslist and the GON Forum from time to time that are resonably priced.