How NOT to fail with the German Refilling method

[ThrillaMozilla]

I ...ended up with a cart too full and ink in the maze. If that happens best plan is to suck out as much of your precious ink as possible with the syringe/SquEasy bottle, then flush the cart.

Oh, dear. I suppose it depends on what you have available, but that's a pretty drastic way to solve the problem. It leaves with a lot of fluid (water +? alcohol) in the cartridge, which will dilute the ink somewhat, unless you can dry it (are you sure it's really dry?) or you flush it again.

Ghwells has dealt with this problem hundreds or thousands of times. Just draw a little air through the maze. Or some people blow into the vent if you have no way of drawing air. I like to also add a drop of water (or water-alcohol mixture in the case of pigment ink) to the vent, to clean it as well as clear it. This might dilute the ink a tiny bit at the top, but it's nothing compared to flushing.

 

[martin0reg]

If you are not afraid of a vampire's mouth, you can blow the vent, while holding the cart over the sink or paper towel...

But the point is: before ink is going up the maze, it saturates the upper sponge.
And this should NOT happen - if the sponge is in good condition.
The lower sponge is for the ink, the upper is for "breathing" or air exchange.

 

[ThrillaMozilla]

It is important not to oversaturate the sponge, and I suppose this could happen by accident with the German method if a blunt needle is butted up against the prism and ink gets squirted into the sponge chamber.

...before ink is going up the maze, it saturates the upper sponge.
And this should NOT happen - if the sponge is in good condition.
The lower sponge is for the ink, the upper is for "breathing" or air exchange.

Are you sure about that? Most of the original photos of the German method show a colored upper sponge. My own OEM HP564 cartridges (not refilled) show a colored sponge at the top, which can be seen by removing the label. Here's a picture of what appears to be a new* cartridge just like mine, opened to see both sponges quite full: http://freedomtoprint.com/2010/06/25/review-hp-564-564xl-ink-cartridge-cracked-open-chips/ .

It might depend on the cartridge design, but the HP cartridges use the Canon design, and are almost identical to the Canon cartridge except for the vent structure. The upper sponge does have a larger (?) pore structure, but as far as I can tell, it does absorb ink normally in many (or most?) cartridges. I have seen some pictures that show part of the sponge with no ink, but I'm not sure which ones are exceptions.


Note
* It's a sponge-only cartridge. The cartridge has not been pierced from the top, and there is an internal groove on the side that has never been wet with ink. Thus, it appears to be a full, OEM cartridge that has not been refilled.

 

[Redbrickman]

Flushing a cart is not any problem, better safe than sorry.

I know the trick of blowing the ink out of the maze, however to be absolutely sure I decide to flush the cart.

As for getting it really dry, that is not necessary either, as a little damp in the sponge is actually a good thing for refilling, as long as it's just a little moisture and not full of water

I have 3 sets of spare carts at any one time so no pressure if I do make a mistake

 

[duncan22]

Some excellent tips but I have always sealed the hole using a warm glue gun, it only takes a second and gives me peace of mind

 

[martin0reg]

@thrillamozilla
let's say it is important not to OVERsaturate the UPPER sponge, the lower should be fully saturated. I think the upper can be damp but should not be wet with ink. New OEMs are looking similar.
As you said, they do have a different structure to achieve this "breathing" though the upper sponge, to let air exchange to the ink chamber. But the problem is, while refilling you can not control the sucking, it depends on the condition of the two sponges...
Lately I filled a cartridge, ink chamber to the top, and both sponges were sucking all the way up, so that one could have fill in much more than the 13ml of ink, definitely too much for the cartridge.

 

[gigigogu]

Had anybody else used a needle from a catheter?

Mine is really thin, 0.7 mm / 22 ga, and, after cutting some plastic near the hub, 6 cm / 2.36 inch long.

With the hole drilled exactly at a corner I was able to slip the needle effortless below the sponge and even to go with the tip beyond the prism (BCI-6 carts).

 

[ThrillaMozilla]

Don't worry, martin0reg. If the sponge soaks it up (during normal German-method refilling), it will also hold it and keep it from leaking. The sponge "decides" how much to hold. That's the beauty of it. You shouldn't have to think about it, as long as ink isn't added to the wrong chamber by accident.