Don't forget or ignore cartridge flushing.

[Defcon2k]

Well, I let them dry quite some time... to me the sponge looked quite dry.
I uploaded the pic to imageshack, but the pic hoster is awfully slow for me... I tried a different one.

 

[jru]

Just thought I would let you know, defcon2k...

I just filled 4 cartridges that had been purged and which had very dry sponges, and which had no hole on top of the spongeless reservoir by using the german refill method.

I could not push the syringe against the small german refill method hole, because the optical sensor wall stops the needle from complete insertion.

But nonetheless, I was able to first fill the spongeless reservoir, and then keep pushing ink into the spongeless reservoir, to force the outflow into the sponge. It helped to push some and then wait to let the sponge absorb (along with using gravity to aim it towards the most white parts of the sponge). It helped to undershoot, since too much pushing and it gets into the vent maize.

And it also helped to let it sit over a jar when done for a while to let any excess ink drip out, before putting them into clips.

But your video showing you pushing the ink into the sponge helped, defcon2k.

So it does not appear to be necessary to make a hole on top of the spongeless reservoir when doing purging, for those of us who fill using the german method.

 

[Defcon2k]

Ah, ok... nice

 

[leo8088]

Periodic purging of ink cartridge should be a preventive measure but not a requirement. The sponge in the cartridges in CIS systems are all half full of ink and half dry. If periodic purging is a requirement those CISS would never work. The cartridges would need to be removed and purged once in a while. The length of the period would not be possible to predict. The sponged cartridge design would not have been chosen by printer manufacturers that include Epson as well.

It is probably not bad if you only need to purge once every 10 refills or more. Since it is really not very predictable, the number would become 3-7 refills if the requirement were 5. That would be not very good. You would probably want to purge before each refill just in case.

This is an issue that deserves a lot of further discussion. I believe all OEM ink cartridges require that they be used within a designated period of time (a couple of years for HP ink cartridges) because of ink shelf life. It will be a debatable perception of ink drying up in the sponge causing sponge seizure.

 

[Smile]

Defcon2,



Since we are using the german method with no hole over the reservoir, I am considering if it might make more sense to get a hand vacuum pump to remove most of the water from the sponge after purging, but leaving it slightly wet so that the ink can be absorbed easier.

I know that pharmacist posted a formula to put into the sponge to help absorption, but a vacuum pump seems preferrable and seems like it would speed up the purge/refill process.

If you vacuum fill it you don't need to purge it at all, unless your ink is low quality and contains not water soluble particles.

 

[pebe]

Ink will always take the easiest path from the tank to the outlet , and in the Canon cartridges that will be mainly across the bottom of the sponge chamber, while the further up the sponge the less ink travels through it.
So at the top of the sponge the ink will be almost static. But air is coming in through the vent and through the top layer of the sponge to get to the 'transfer port' into the tank, and that will tend to dry the ink there.

I have always assumed that the cartridges need purging because the ink at the top of the sponge dries out.

 

[jru]

Smile,
I can see how this is true for cartridges in use, but I just got a bunch of used dried out OEM carts.
Seems like they need to be purged, regardless of how they are going to be filled, no?
But I am still thinking about getting a hand vacuum pump to have on hand.
I saw a hand vacuum pump kit in auto parts listings that is used for brake bleeding, that came with a 16 oz container and hoses. http://www.mityvac.com/pages/products_hvpk.asp Where did you get yours?

Pebe,
Hmmm... what you say makes sense; makes me think that maybe we should consider not completely filling the sponges right to the top? But how do we know how far up the sponge to get saturated?
Wondering if others have been filling your sponge right up to the top when you refill.

 

[Defcon2k]

I have always assumed that the cartridges need purging because the ink at the top of the sponge dries out.

If that is the reason it should not matter how often you refill, but only how long your carts are in use.
I can't say, but my experience is this: My first set of carts is in use since more than one and a half year now without flushing. I don't print that much, and because I also have a 2nd set of carts, I refilled them only about 10x per each color.
Well, perhaps the cart stopping to work properly so that a flush is necessary has a totally different cause... I don't know. I will just use my carts until they show problems with the ink feed, and then I'll flush them. Perhaps this will happen next month, perhaps in 2 years, perhaps never... who knows.

 

[Grandad35]

Just to add my 2 cents to this discussion...

I have always been under the impression that it is the "filter" that gets clogged - not the sponges. The filter is similar to that used in cigarette filters, and can filter down to the micron level. I suspect (but have no proof) that the dried and hardened residue from the sponges works its way down to the filter, where it builds up on the top surface. Purging with hot water helps to dissolve any such residue and also flushes it out of the cart, even if it doesn't dissolve.

I blow into the vent port of every cart to get a few drops to drip out before installing it into the printer. This guarantees that the bottom of the filter is wet, making it easier for the printer's cleaning cycle to establish the "ink link". It also lets me know if the filter is becoming clogged, based on how much pressure is required to get the ink to drip. When this pressure begins to rise (I can't explain how you know - it is based on long experience with clean and clogged carts), I know that it is time for a purge cycle. Even if only a few carts are showing high pressure, I purge every cart in my rotation at this time. I also pull the print head, push an alcohol/water mix through every color, then blow it out with low pressure compressed air until the carts are dry and refilled.

When I have to replace any cart (always on "empty" - never on "low"), I always check the ink level in all of the carts. Because a lot of ink is used in the "cleaning cycle" when any new cart is installed, I prefer to replace every cart that is low to minimize the number of these cycles and the amount of ink that is pumped into the felt pad that functions as the "waste ink tank".

It is possible that achieving a constant ink level in the sponges with a CIS greatly reduces the buildup of this residue in the sponges and reduces the need for purging.

 

[leo8088]

Interesting point of view, Grandad35. But whether it is the sponge or the filter it does not explain why some people don't find it necessary to flush the cartridges but some others do. For the sake of the printer's safety, I agree that it is a good thing to do once in a while. The problem is whenever one of my cartridge is empty I simply have no time to go the long route to flush, dry then refill. I kept on promising myself to do it next time but never really get to do it. That's why I ask if I have been lucky or is there really a need to flush.