Keith wrote:
I've even bought and old Epson 3000 just for its renowned ability to print densely.
If it is the old wide format version, which I and a lot of others on this forum had some time ago, your might end up finding that the negatives of that printer outweigh the benefits, which at this time I'd say would only be price. It has relatively large dots, serious paper transport issues, and carts with couplings that, unlike modern ones (4000 and 7600 one), do not tolerate multiple refilling well.
What size do you actually need to make your circuits?
... they also have specail "needles" for refilling the Epson 3000 "bag" cartridges. I've just used a chopped off and smoothed hyperdermic needle ...
The modern carts have a wider throat and a valve that shuts when the cart is removed from the printer. The MIS bottom fill adapters, and various modifications of it, make rinsing out, re-filling and otherwise dealing with wide format carts much easier. The wide throat versus a needle makes all the difference in things like rinsing out carts or re-filling them.
...I actually flushed a tri-color cartridge with distilled water until it came out clear, but drying it is a problem. ...
I assume all these inks are water based. At least with the modern ones it's easy enough to get the residual clear rinsing fluid down to a de minimus amount. I use a fluid for rinsing that is compatible with the ink base. (I have formulated clear bases for both pigments and dyes.) Distilled water is fine, particularly initially, but a clear ink base that has compatible surfactants (for cleaning) and other ingredients, as well as an appropriate viscosity reduces my concerns about residual fluids in the cart.
After I have rinsed a cart enough that the returning fluid is clear, I simply inject air into the cart, hold it bottom down, and pull out the ink. A couple of these gets it down to minor bubbles (which are compatible with the ink base). I then do a final flush with the new ink to be used. Just a few MLs at this point takes the process to the point were I just do not worry about it. (Way less would probably suffice.)
Paul