Best Sources for C-41 Developer Only

I have a bunch of CPAC C-41 chemicals, but it appears the part C of the developer is too old. All the others are just fine. I've read the thread to have the CD4 in place of part C. But I may just want to buy the developer kit together, not the entire C-41 kit.

I do not process steady large quantity of film. So maybe the 1 liter package is good for me. There has been lot of discussion on this before, but a lot of them are probably outdated. Thx.

You can get that in powder form from Photographer's Formulary or Artcraft Chemical. There are notes in the archives here about the amounts to use to replace Part C. Stored properly the dry powder should last for a long time.

Here: http://stores.photoformulary.com/color-developer-4-cd4/

Or

Here: http://www.artcraftchemicals.com/products/products-page/general-chemistry/a-m/cd-4-part-1095/

or, if you prefer:

Here: http://www.ebay.com/itm/CD-4-Color-Developer-4-0-5-Pounds-/150654576341?pt=LH_DefaultDomain_0&hash=item2313b666d5

Incidentally, keeping the bottle of developer full and storing it in a ziploc bag in a refrigerator will extend the shelf life, to maybe double. Do not freeze, that doesn't work, my previous comments to the contrary not withstanding.

Unlike the unused Part C, the appearance of the mixed developer is no indication of whether it is good or not. As a quick test, clip off a small piece of leader film, drop it in a bit of the developer and see if it develops to black in 3 - 4 minutes. You can do this at room temperature. If it develops to black in my experience the solution should be OK. If it doesn't or just partially develops (say just gray) then throw it away and make new. I keep a small pile of clipped off, exposed leader just for this purpose.

Others may have better tests than this but it has worked for me. As always, YMMV.

I think someone said the part C contains not only CD4, but something else. Is that true? Or the CD4 can just replace the part C, no problem?

There may be something in the Part C other than just CD-4, as a preservative or something, IDK. However, you just need the CD-4.