Does ink clog in brass tubes?

[Lothman]

Hi all,

I'm running an Epson R2400 with 3rd party refillable cartridges and Image Specialists inks. I converted the printer with an externa wast ink tank. Because cheap to get an very handsome I use a fuel tank of model aircraft for this purpose. In order to connect the flexible rubber hoses thesy use small brass tubes as connectors.

First every thing went OK but after some months I got smeared prints after cleaning cycle. I found out that printer no longer manged to pump the inks pads dry therfore the smears. The ink tends to clog in the brass tubes, but not in the silicone hose before and after the brass tube. So I converted to plastic tubes as a connector and will see what happen.

Any similar observations or an advice of the ink specialists around here in the forum?

Happy new year and best regards
Lothman

 

[ghwellsjr]

I found a similar problem on a Canon printer. See this link. Basically, the problem is that if the tubing is exposed to air, the ink can dry out inside it. I tried submerging the ends of the tubes in liquid which no longer had the problem but required continual monitoring and I gave up on the idea. I think the successful systems use a collapsible bladder that essentially doesn't allow fresh air to dry out the ink in the tubing.

 

[pharmacist]

Hi Lothman,

your problem is the slightly alkaline pigment ink. I use the same ink in my Epson Pro 3800 and it has a typical ammonia smell. The increased pH is necessary to maintain ionic strength to keep the pigment particles suspended, but it also can dissolve copper (brass is made chiefly from copper) by chelating mechanism.

 

[Lothman]

Basically, the problem is that if the tubing is exposed to air, the ink can dry out inside it. I tried submerging the ends of the tubes in liquid which no longer had the problem but required continual monitoring and I gave up on the idea.

I also put a silicone hose inside the tank (from the end of the brass tube to the bottomof the tank) and always kept a liquid level high enough to prevent drying. I'm 100% shure that this has nothing to do with drying out.

I think the chemical reaction, as pharmacist described, is the reason. By the way the pump of the R2400 is rather strong. It managed to build up such high pressure that the silicone hose popped of the brass tube