Finally wrapped this up. NL tested samples with DC white and said they both discharged...well yeah, a lot of things get covered up by an HO white. I explained that the issue was regarding less highly pigmented colors, as demonstrated by what happened running clear, 5% activator DC base and asked that they test a clear DC base and see if they can repeat our results. I guess they were too busy to do that so our distro, SLC, actually had another of their clients test the samples. This shop repeated our exact results in their testing. I have no idea what inks/curing/screens/etc. this other shop has in place but the results were the same so SLC showed this to NL and I guess it was an eye opening experience for them.
I don't know if NL or SLC footed the bill but they actually took the whole order back, a good deal of it printed. We didn't ask for that so kudos to both of them, especially SLC Activewear, this distro has been killing it for us this year in every possible way, this just being one of them.
NL seems genuinely dedicated to this and I have a lot of respect for that. The VP or something like that wanted to talk it over as well but we haven't connected. Still, it shows a lot of give a damn from them regarding their discharge guarantee.
We've begun to slowly spec DC on the 3600 again but never again with clear or low tint inks. It's not that I don't believe you all but we simply are not seeing the "never an issue" "no problems" results you are. Our suppliers test run confirms to me that it's not related to anything in our shop and I'm not risking scrapping 100s of Ts again with this brand. For now I'm being very cautious but am tentatively hopeful that we can get this shirt going for DC printing again. Funny thing is we have DC printed the 6210 blends in some colors for years now with absolutely zero issues ever so it's ironic to be getting issues with the guaranteed cottons.
So far it's been OK, seeing some good prints on these. These shirts are inferior to many we run for DC but they do discharge. We ran 425 Midnight Navy's with a 6 color DC print on Friday through 225 mesh with some 45lpi tones and overprints, bright colors and it was pretty smooth. There were about 5-10 in the bunch that did not discharge like the others, the colors looked dull. The dye lots are clearly different, I could see the difference easily from size to size but we simply ran one of each size to check before cutting in. I can live with this though.
Final verdict is I'm thankful for the experience, it's helped us setup better protocol for our DC work. It's also pushed us to do some creative thinking about what we can and cannot do with DC ink to overcome dye lot variance and fabric related issues.