How old are your OEM cartridges, maybe to old...?

[avolanche]

The standard glue gun is not good to use, you need the bigger glue gun that can produce higher temperatures, works a threat...

I need a new glue gun anyway.....good time & reason to buy a nice one

 

[jjohnl]

With @stratman
I needed to investigate this most usual loss of ink quickly, because my refill holes were filled with hot glue and never leak once cooled, so this was new to me.

Are you saying that you fill the refill holes with glue instead of plugs every time you refill? (I clicked on the link in your signature that says, "My own refill method" but it doesn't do anything.)