Possible Yello Gello Explanation...

[The Hat]

Up to now no one has had any idea where Yello Gello came from and what causes it, other than the fact that Canon introduced it to cause us Refillers huge headaches.

Myself being a science retard in the chemical field am now attempting to give my explanation as to what Canon has done to cause the “Yello Gello” to occur as we commonly know it here.

I watched a TV program that was unrelated to inkjet printing or anything to do with Dye inks and wondered if that was the Technology Canon were using in the CLl-42 yellow carts.

What I believe they used is a Super Absorbent Polymer (SAP) that when it comes in contact with water/ink turns into a transparent gel, and the OEM ink is not affected by this because it has some sort of antidote (chemical) in it.

I reckon they have put some sort of Polymer into the outlet sponge and any attempt at refilling causes this chemical gelling reaction in the sponge and flushing with anything other than water will clear out this problem leaving no lasting effects..

 

[kdsdata]

Sounds a bit conspirationalist. Did Canon actually make a statement to the effect that "a substance" was added to make it harder for us refillers? Or was it not possible that something was done to make the yellow ink more effective on the printed page, such as, for example, the printed yellow dot not bleeding into the adjascent dots. The Yellow Gello may well have been just a bonus for them.

 

[The Hat]

@kdsdata, It was always assumed that Canon added something to their yellow ink that made it react to 3rd party inks and water to produce this jelly like substance, in my mind it wasn’t a bonus but very deliberate on their part.

While the yellow colour itself inside the cartridge looked completely different to any other yellow that came before, it still printed the very same, see this old post back when these cartridges first appeared on the market..
https://www.printerknowledge.com/threads/canon-pro-100-cartridges.7242/

Despite the obvious problems that it gave the Refillers, Canon were very carful that it didn’t damage the print head in any way, but only caused it to clog up for a period of time, frustrating the Refillers even further...

 

[avolanche]

So, it's possible that removing the outlet sponge and replacing it with any other color (say, from a CLI-8 cartridge) would eliminate this issue?

 

[stratman]

It was always assumed that Canon added something to their yellow ink that made it react to 3rd party inks and water to produce this jelly like substance, in my mind it wasn’t a bonus but very deliberate on their part.

Why only Yellow?

What about @mikling 's testing that determined the/a cause of Yello Gello? I thought some of his testing was outside the cartridge.

Next you'll be saying St. Paddy didn't drive all the snakes in Ireland into the sea.

Happy St. Paddy's day!

 

[The Hat]

o, it's possible that removing the outlet sponge and replacing it with any other color (say, from a CLI-8 cartridge) would eliminate this issue?

Probably but that gets a bit messy, so it might just be better to flush the yellow cart after using up all the ink in it, but you could be the first one to give it a try..

What about @mikling 's testing

His guess is nearly as good as mine, but no cigar..
My theory is once the yellow cart is removed and replaced by 1 containing 3rd party ink, gelling does not occur in the print head, because the offending cart is out of the equation..
Happy Paddys Day @stratman, Sláinte..

 

[stratman]

My theory is once the yellow cart is removed and replaced by 1 containing 3rd party ink, gelling does not occur in the print head, because the offending cart is out of the equation..

Or it's that the print head is flushed out with the aftermarket ink in short order, leaving no time for the gelling.

Maybe if you were to open up your Pro-100 and examine the waste ink pads....

 

[SkedAddled]

I reckon they have put some sort of Polymer into the outlet sponge and any attempt at refilling causes this chemical gelling reaction in the sponge and flushing with anything other than water will clear out this problem leaving no lasting effects..

This makes no sense from a manufacturing-efficiency standpoint. With 8 carts to the CLI-42 set, what could they gain in cost-savings and efficiency by specifying only ONE of the eight should have the polymer-laden sponge? The carts are no doubt physically identical prior to chip application, ink fills and label application. Completely separate processes for yellow-only cart manufacture would surely require additional expenses and procedures than the rest, which is not how large-scale manufacturing moves efficiently. And as mentioned, and demonstrated by @mikling , the ink solution by itself has shown to gel under controlled conditions when removed from the cart. Your theory would have to assume that all sponge material within a CLI-42 Yellow is, indeed, laden with said polymer for the idea to hold it's own. This could be true, but I would ask why no other of the 7 colors are affected in this way.

My money's on the ink formulation, not the sponge(s).
There's something in the ink liquid we don't know about; it's certainly a closely-guarded secret,
but it's what Canon managed to develop to their very specific standards and have it be a reasonably cost-effective solution, just like the other colors.

 

[The Hat]

My money's on the ink formulation, not the sponge(s).
There's something in the ink liquid we don't know about; it's certainly a closely-guarded secret,
but it's what Canon managed to develop to their very specific standards and have it be a reasonably cost-effective solution, just like the other colors.

I have to agree, your theory is as good as mine, but the reason why they didn’t use other colours is maybe they couldn’t get it to work properly and still protect the print head, but they did go to huge expense to make this happen.
They make all their money in ink sales and not in printers...

 

[websnail]

FWIW.. I've had this discussion with a few chemist type folk and the educated guess received was the ink formulation.

Short version... New dye that has improved vividness or other desired properties but, it is not soluble with standard ink bases. So, a co-solvent is used which the dye will dissolve into and which, combined, is water/ink-base soluble. So, while the ink is happily undiluted, it's just fine.

Now, my understanding is that the jelling issue doesn't present itself until the original ink has reached a critical dilution point where the co-solvent/dye mix can no longer stay in solution so it all drops out and recombines with whatever diluting agent (refill ink, water, etc..) contains. Again it's just an inferred guess but it's the new chemical bonds/compounds that create the jello.

As with any theory, it'll bear scrutiny and there may be some Canon employed chemist chortling away at the various theories but on a more pragmatic note. When it comes to dealing with the issue, thorough cleaning using pure water and appropriate cleaning solutions does seem to remove all traces of the original ink thus rendering the cartridge "safe" for refilling.