Do I have a problem with dry sponges

[Redbrickman]

I do use the German method but I have also filled bone dry carts that have been sitting for months without any ink and flushed and dried.

Now I am wondering why I have not encountered a problem and offer a possible explanation.

I'm a bit of a lazy refiller

No that's not the reason but here is what I do contrary to some advice.

I fill the reservoir German style to about 80% full using a squeeze bottle.

I pull the needle back just a few mm and leave the cart upside down for a few secs, then turn it right way up after the bottle has gone back to it's normal shape. I do not worry about removing the needle before releasing the pressure on the bottle.

I then leave the needle in and turn the cart right way up, and rest it, so that the needle is more or less horizontal.

After the ink is absorbed into the sponge for a few minutes i go back to the start and fill to about 80%, then remove the needle after the bottle is back to shape.

I have had no leaks or any other issues with this method, except for a stupid overfill, and my theory after reading Miklings post, is that the ink can wick along the needle slightly to keep the bridge in contact with the reservoir by capillary action.

The other bonus is that it only needs the needle to be inserted once for each refill, so less sponge disturbance.

 

[ThrillaMozilla]

I just got back from a short vacation. Nice photos, Mikling.

Looks like you've made the other kind of hummingbird feeder. Amazing. Ink can't come out while air is going in. Who'd a thunk they'd make the opening that small?

About that last photo -- if you put it in contact with a towel, it will drain, right?

 

[rodbam]

I would suggest you read through the thread again and youll see the facts that mikling presented
are not directly critical of the German method but any filling method that may disturb the ink bridge will also have this problem.

I think what Mike said below would be considered a criticism of the German method. For me the method is very worthy of the German name & the attention to details we come to expect. Just by the fact that ink will travel along the needle into the ink bridge before it's withdrawn. The original videos of this method show how once the cartridge is full it's placed right side up on a glass & allowed to sit with the needle still in place to saturate the sponges before topping up & withdrawing the needle, this surely makes doubly sure the ink bridge is properly established

When I grew up I always admired german autos and their engineering and their great suspension systems ( not electronics) and I held german engineering in very high regard ( I was trained as an engineer). I am not so sure that this convenient refill method deserves the german title really as it introduces a potential problem that had been overlooked or not explained prior to this.

Panos just peer reviewed Mikes theories so I don't think he shot the messenger at all. Even though I know bugger all I also peer reviewed Mikes excellent work

 

[mikling]

Don't misinterpret that the lockup will always occur because it won't. Only in certain circumstances it could occur. If the sponge is pretty saturated and the wall is also wet, you likely will not encounter a problem at all. But if ever there is a problem, investigate this possibility.

Now the question was also asked if that makes the CLI-8 superior to the BCI-6. The answer is yes because the design improved. Take this into context because the BCI-6 did not really give "problems". But there was a reason why the groove as added and since Canon had to make a new mold to accomodate the chip, they possibly incorporated other small improvements at no additional cost. So why not make it "better". I used the BCI-6 for a couple years and none gave me problems so there's no real need to worry about it at all.

One thing that could make problems though is that some refillers "hunt" for the tunnel . When they do this, so they inadvertently shift the lower sponge away from the hole? If they do, then it is not good.

It is important to realize realize that the ink does not flow out of the tank but rather pulled out by the absorptive properties of the lower sponge. This pulling is continued all the way down to the printhead. If you have a leaking tank, then the pulling becomes pushing because the lower sponge becomes more than fully but oversaturated.

In any case, the thread was about the sponges and I just thought that I would show that as long as the bottom sponge is saturated, the printer will function properly.

Finally, does the sponge always need to be very saturated? Heck no. Even when the tank is empty, the printer still prints fine and will continue to do so until the sponge contains too little ink. Now who wants to perform the experiment exactly at what point the sponge contains too little ink? Warning. It could be a long way because all the integrated printhead cartridges function with a sponge that starts from a saturation point that decreases as more and more printing is done. The cartridges with tanks starts with a saturation point that stays the same until the tank empties and then follows the pattern like one of the integrated head cartridges.

So I would have said that the cartridges that Rod initially showed would have worked fine and he was probably being overly cautious.

To answer grandad35, question about opening up the bottom cart. I did not. The reason is that as ghswellsjr showed the abosrption of the lower sponge is so aggressive that as long as it come into contact with ink, it wants to "grab". So I think assuming that the bottom sponge was fully soaked might have been correct. About measuring the displaced volume of the lower sponge. Yes, that might have been a good idea but when I started the test, I had different objectives that kind of shifted as I went along. But I think I know the objective of the question is he wishes to see just how much"extra" you could put into the BCI-6 and it is worthwhile to get the extra - Well, I went out and tried to measure the capacity of the bottom sponge by itself tonight. And now one word of warning.... don't squeeze the sponges. It permanently changes its properties. - it does not want to expand out and fit as snugly as before. The sponges are now destroyed.

I measured the capacity of the sponge cavity and it is around 10 - 10.5 ml. So if that were the case, and the sponge held around 8.5 to 9 ml till dripping, then it would appear that what grandad is doing is the correct strategy. gasp! overfill a bit. It won't hurt and gasp! what the old timers had been doing by filling the tanks as full as possible with no drips was a smart strategy. I will question my own measurement of 8.5 to 9 ml prior to dripping as it seems high. Even if I were to say that my measurement was off by say 0,5 ml. and it in fact took 8 to 8.5 ml to fully saturate the sponge, the worthwhile extra amount of ink would still amount to around 2.5ml or more by my estimation. Perhaps someone who has not destroyed the sponge like I had could take this part up and repeat the experiment. ghswellsjr has some open sponges. That really means that oversaturation and its bad effects might have been overstated. Perhaps as full as possible as long it does not drip before being put back into the printer is all that counts.

Gosh isn't that what was always stated before in the early years of refilling cartridges. Have we gone full circle about the saturation issue? Frightening isn't it.
What is old is new again.

If such is the case, then the thought that Canon does not fill the sponges as much as they could really likely has a lot to do with limiting capacity and nothing else.

 

[mikling]

Panos

Peace.

No more about this aspect please guys, I became sensitive after a certain person's assault.

 

[rodbam]

That subject is now closed & we're back now to the universal theory of everything spongy
This thread has really given me the confidence of now looking at my refilled cartridge & making a judgement that it will work fine. If it fries my print head you will be hearing from my lawyer Mike

 

[ThrillaMozilla]

Mikling, you asked what is going on in those last photos. I have to answer with questions because I can't tell for sure what you did. Did you put that sponge back wet or dry? And will that cartridge drain in the state that it's in in the last photo?

 

[leo8088]

If the sponge is pretty saturated and the wall is also wet, you likely will not encounter a problem at all. But if ever there is a problem, investigate this possibility.

Don't you think if the sponge is so saturated ink will drip off from the outlet? I have seen enough instances that ink drips out of the print head nozzles because of oversaturating the sponge. Perhaps this is already concluded. I have not read the entire thread in detail. But by saying this it can be misleading.

 

[leo8088]

The purpose of the groove is to ensure that there is a continuous body of liquid ink from the tank to the sponge. This allows the "surface energy" or surface tension to be reliably set up. So as the ink is removed from the bottom sponge, ink is PULLED out of the tank to replenish it. The network of close proximity fibers in the lower sponge sets up a very strong surface energy network, Strong enough to pull ink out of the tank. Try to understand that. It behaves like it is elastic. So it is not the head pressure, that allows ink to flow out but the surface tension aspects. There is negative pressure within the tank BUT the overriding force or effect is surface tension. That outlet hole is also sized to have this effect. You can imagine if I cut the hole exiting the reservoir, the liquid will leak out and it will. The hole is actually designed to be withing a certain size.

Now why did Canon add this groove over the years. The first answer I postulate is that it would improve the functionality of the cartridge. Yes, that is reasonable or else theywould not have done and continue to. This is where we need to keep calm. Canon likely experienced the situation I showed in my final picture where the sponge was not drawing ink out of the tank. The i"nk bridge" I will call it that, was broken. Once the ink bridge is broken, ink receded back into the tank and the ink within the sponge would get consumed and the tank would still show itself to be full of ink. That ink bridge will answer many questions as to why some cartridges do not feed properly.

Ink PULLED out from the tank to replenish the sponge? I hardly can agree with this concept. Ink is not pulled out from the tank. I suspect a misunderstanding of how the tank works based on this word PULLED.

Ink can not be pulled out without something else first. This something is AIR. There must be a presence of AIR at the slit at the bottom of the tank. Air gets there because the ink level in the sponge gets lower due to consumption of the ink. When air reaches the slit it enters the tank. Air in a liquid will want to move up to the surface. This allows a same volume (of the air) of ink to flow out of the tank. Before air reaches the slit ink will only be drawn out from the sponge. The sponge can not and does not PULL any ink out of the tank. It is the atmosphere pressure that keeps the ink in the tank. Only when there is air entering the tank it allows the ink to FLOW out into the sponge. If you pull out a cartridge that is half emptied you can sometimes observe air bubbles rushing to the top of the tank inside the reservoir.

I just checked an empty BCI6 cartridge. There are groves there too. You have invented an idea that Canon added the groves to CLI-8. If the upper sponge is choked up by dried up ink due to infrequent refill air can not reach the slit through the groves easily. This causes the ink difficult or not flow out of the tank to replenish the sponge. That's when you will get a clog in the print head.

 

[rodbam]

Pulled out may be the wrong word but I wonder if as mentioned before whether the sponge wicks the ink out to keep it saturated as the sponge is in contact with the ink in the ink only chamber. A colonial boy would call this being pulled