Carts repeatedly lost to mold (?). What to do?

[elenhil]

Try giving the purge unit a good clean and flood it with window cleaner to finish..

Okay, I belatedly followed out your recommendation (and replaced the carts;. the old ones were probably - can't tell for the darker colours - beyond hope anyway). Will monitor the results.

However, the purge unit was a bit too deep down there to easily reach, so I used a syringe to flood it. Thing is, the needle had a notched edge and I inadvertently 'caught' one of the sponges on top of the purge unit.

I was surprised to find it, well, not very spongy. Seem like either the leftover ink (or my window cleaner) hardened to a glaze. Is that normal? Should I remove the sponges and give them a good manual clean to remove whatever makes them hard?

 

[PeterBJ]

The purge pads are made from a hard and porous plastic or ceramic material. You can read more about these pads in this post.

 

[elenhil]

The purge pads are made from a hard and porous plastic or ceramic material. You can read more about these pads in this post.

Oh! Very insightful, thank you! Now I will lose my sleep thinking whether I inserted the square 'sponge' proper side up (or, indeed, the cut corner facing top-left)...

 

[elenhil]

Well hell. The mould is back, and the new carts are set to be ruined. Again. And I cannot help but wonder, if the mold had been in the print head, why shouldn't it come back, since I did nothing with the head itself and it probably became a safe refuge for it?

 

[x64]

As far as my knowledge goes, water based print ink commonly has a very slight amount of biocides as an additive to prevent mould and other life from inhabiting the solution. If you are sure that it is mould, perhaps the aftermarket ink you used before didn’t contain it or in too slight amounts.
Regarding the original carts I’d think they contain a correct amount, but might have lost their effectiveness past their expiration date. I’m no ink expert, chemist or microbiologist, but even if their effectiveness would still hold up, it won’t be sufficient to rinse out a growth, but rather an exact amount to keep a solution stable.

To be honest though I’d think black ink is leaking into your carts. As described in this post on the forum with an example of the exact carts that you are using.

 

[jimbo123]

might be time to try some fresh ink or a full brand new set of genuine canon ink carts.

J

------------------------------------------------------------------------------
• Active Printers: MX700(2007), MP980(2008), MX870(2010), PRO-100(2013)
• Stored Printers: IP4500, MX700, MX860, MX870, MP980
• Past Printers: MP830
• Method: German Durchstich Method
• Ink: Hobbicolors, then OCP, now ASPEN
• Misc: Squeeze bottles - so much easier than syringes

 

[elenhil]

I am using genuine Canon cartridges. And leaking/cross-contamination is an entirely new (and previously unknown to me) possibility. I had thought my yellow ink turning dark was definitely mould. Is there a way to be sure?

 

[jimbo123]

are your genuine canon carts brand new or have they been refilled ?

J

------------------------------------------------------------------------------
• Active Printers: MX700(2007), MP980(2008), MX870(2010), PRO-100(2013)
• Stored Printers: IP4500, MX700, MX860, MX870, MP980
• Past Printers: MP830
• Method: German Durchstich Method
• Ink: Hobbicolors, then OCP, now ASPEN
• Misc: Squeeze bottles - so much easier than syringes

 

[elenhil]

are your genuine canon carts brand new or have they been refilled ?

J

------------------------------------------------------------------------------
• Active Printers: MX700(2007), MP980(2008), MX870(2010), PRO-100(2013)
• Stored Printers: IP4500, MX700, MX860, MX870, MP980
• Past Printers: MP830
• Method: German Durchstich Method
• Ink: Hobbicolors, then OCP, now ASPEN
• Misc: Squeeze bottles - so much easier than syringes

'New' as in bought, not refilled. They were probably produced a longish time ago

 

[x64]

I am using genuine Canon cartridges. And leaking/cross-contamination is an entirely new (and previously unknown to me) possibility. I had thought my yellow ink turning dark was definitely mould. Is there a way to be sure?

I doubt it would be worth your time, as much as I love to use and maintain retro hardware sometimes you got to bite the bullet and move on. Some parts and things like gaskets, glue, lubrication etc could be too worn or degraded to fulfill their function, even though they look visually OK.
If you can isolate the issue it could potentially (!) be replaced or repaired, requiring time, troubleshooting and replacement parts. We are talking about a printer that in 2005 cost around €100,- do the math.

As a last pointer I would look into whats written on the cross contamination. And though I have never dealt with the specific issue, I have opened some old sealed cartridges to reveal an ink mess because the bottom sealing gasket had lost it's tension due to ageing.