Shouldn't the lower sponge change colour?

[PeterBJ]

Unless you drill a small hole on the top of the ink chamber and use that for top fill you cannot fill the ink chamber 100%. An air bubble, that might or might not get trapped in the channel between the ink- and sponge chambers, will always be present if you use the sealing ball hole for refill. A new Canon OEM CLI-8 shows no air bubble in the ink chamber, so there is no risk of an air bubble getting trapped during transportation. That's why I think a special technique is used.

 

[The Hat]

Unless you drill a small hole on the top of the ink chamber and use that for top fill you cannot fill the ink chamber 100%. An air bubble, that might or might not get trapped in the channel between the ink- and sponge chambers, will always be present if you use the sealing ball hole for refill. A new Canon OEM CLI-8 shows no air bubble in the ink chamber, so there is no risk of an air bubble getting trapped during transportation. That's why I think a special technique is used.

The tool used to fit the ball probably pulls a vacuum just as the ball is been placed ..

 

[PeterBJ]

The Hat wrote:

The tool used to fit the ball probably pulls a vacuum just as the ball is been placed ..

That sounds plausible. I have noticed that new OEM BCI-6 cartridges are not completely filled but have an air bubble in the ink chamber, new OEM CLI-8 and newer cartridges have no air bubbles in the ink chamber. BCI-6 have no channel between the chambers, but CLI-8 and newer do have this channel. Maybe Canon refined the filling technique to avoid inkflow problems and customer complaints because of an air lock in the cartridge?

Knowing Canon's filling technique might lead to the development of the ultimate refilling method

 

[PeterBJ]

In post #4 mikling wrote:

...The final step is when the tank is filled and plugged up, I tilt the cartridge so that the tank side is up and I tap the cartridge a couple times. This will release any air that might be trapped in the ink bridge tunnel/canal between the sponge and tank compartments. This canal is a refinement to provide better ink flow from the tank to the outlet and is not present in older BCI-6 cartridges. On the CLI-8 and forward this is there...

This is a good tip and it also applies to the German refill method. I think a trapped air bubble was the cause of this problem: http://www.nifty-stuff.com/forum/viewtopic.php?id=7744

This shows that tried and tested refill methods can still be improved on, so thank you very much for the tip

 

[The Hat]

That's why I think a special technique is used.

I was working on just how Canon can get ink into their dry sponge and leave no air inside the cartridges.

Then it hit me, its simple if they heat the inks before injecting it into the cartridge it will get absorbed much quicker
and when the cartridge is then sealed it will pull its own vacuum as the ink cools down.

Now do I get the cigar..

 

[PenguinLust]

Hmm... maybe nuking the ink before adding would be a good idea. We'll have to ask Octo if they can send us ink is microwave-safe containers.