Clogged Canon print head

Fotofreek: Thank you for the purge explanation. We are glad you are a part of the team. I thank every one for helping us get printing again. Our printer sat for three unused days at the church. I tested it this morning and all works well. I have a note on it to not turn it off and we will run test pages twice a week un less some one wants to actually use it. With no side issues to deal with it looks like the boiling water fix is good for the long haul. Word is getting out among church members. There are several print head that are in hot water. Ill yall know if I hear anything
 
dralsop,... Please hold off on passing out the "Boiling" approach. I just tried it on one of my printhead and I damaged it. I don't know if it is ruined yet. What happen is the excessive heat broke the seal inside the printhead between the ceramic wafer and the rubber ink supply seal. If you have ever looked at some of the photos that Grandad35 has posted you have seen the seals inside. They look something like the suction cups of an octopus. Anyway, when the rubber is overheated it softens up and looses it's seal to the ceramic. Then, when the PH is primed, ink leaks internally and this causes contamination.

I have never had contamination with this head before. It only had one or two nozzles in the Cyan that did not print and every other top line in the Magenta matrix would not print and 6 random nozzles would not print. The black was always fine. I did a normal cleaning and then tried you "Boiling water" approach but I did not use real boiling water. I only heated it up till it was really hot. I would estimate about 170 to 180 degrees. Now my problem is that the Cyan ink has leaked over into the Magenta section and contaminated it. I immediatley knew this was the problem so after 3 nozzle checks, I took the PH to the freezer and let it cool down and even made it cold. This could bring back the stiffness of the internal rubber seals.

After it cooled down I was able to get 4 color bars printed but there still is a lot of contamination, especially at the beginning of print of the 6 color bar chart. I let the printer rest for an hour and now it is all back to printing everything in Cyan so that color has leaked internally to all nozzles. The other news is after all that cleaning with the very hot water, not one bad nozzle changed from what it was before,... not even one.

So I would not encourage others to try this approach as they could damage the printhead beyond repair. I don't know what you did different or if you were just lucky but I think boiling water, or near boiling is not going to be a good technique.

Grandad35, if you're reading this, have you every found any way to repair the seal between the rubber and the Ceramic in the Prinhead. I suspect that when the Head is manufactured, Canon puts some kid of adheasive coating on the ceramic wafer before they mate the two together. I tried to tighten the screws that hold them togther but it won't go any further. The only good news in all of this is that the back section is not contaminated and is still perfect. This is mainly what I use the printer for anyway. It still will print color images but nothing comes out what you expect.

I'm going back to my cleaning in the sink, using hot water their but with the hand sprayer forcing water against the nozzles. There was another member that has used a garden sprayer with a single focused stream of water that seemed to really break loose the tiny clogs at individual nozzles. I'm going to try and follow that path for awhile. If you know of something to fix the seal let me know. I have taken one other printhead apart down to the ceramic and never got it to work because the seals leaked internally. It is easy to get apart but getting it back together the way Canon has made it is a different story.
 
Trigger 37 said:
dralsop,... Please hold off on passing out the "Boiling" approach. I just tried it on one of my printhead and I damaged it. I don't know if it is ruined yet. What happen is the excessive heat broke the seal inside the printhead between the ceramic wafer and the rubber ink supply seal. If you have ever looked at some of the photos that Grandad35 has posted you have seen the seals inside. They look something like the suction cups of an octopus. Anyway, when the rubber is overheated it softens up and looses it's seal to the ceramic. Then, when the PH is primed, ink leaks internally and this causes contamination.

I have never had contamination with this head before. It only had one or two nozzles in the Cyan that did not print and every other top line in the Magenta matrix would not print and 6 random nozzles would not print. The black was always fine.
Click to expand...
Hi Triggeer37, I was really planning to use the boiling water approach too because I couldn't get hold of the printhead from the seller. But I am holding it back now until further input. How did you conclude your printhead has been damaged? Is the damage exterior such that it's physically visible to the eyes without 'dissecting' the printhead internal structure. Or the damage you referred to occur inside the printhead?

By the way, the suction cups picture from Grandad35 which you referred in the above reply is the 3rd/4th pictures, right?

And would you be able to produce a picture of what you meant by 'ink leaks internally and this causes contamination'. It will help us reader to better conceptualize what 'leaks ' you are referring and where the leaks & contamination occur.
 
This thread started by Grandad35 just keeps getting better.
I am having to go back and read reread this thread from the beginning.

Lin look at page 8 and 9 of this thread for more print head pictures by Digitalartist71.
 
Lin,... I guess my post was nat that clear on the damage. When I say the Cyan leaked internally over to the Magenta nozzles, what I mean is that when I print a nozzle check, I get mostly Cyan ink in both the Cyan nozzles and in all the Magenta nozzles. There is no way to get Cyan ink into the magenta nozzles unless there is an internal leak at the rubber seal. I'm amazed that it also has not leaked over to the Yellow ink cart. The black and the yellow are perfect, the Cyan is the same as it was before the boiling water. It still has several random nozzles that are clogged. The nozzles for the magenta are also exactly the same as before the cleaning, only they only printed Magenta ink for a couple of color bars and then converted to full Cyan.

The leak is still there and when I let it sit for 1 day, the ink actully "Wicked" back up into the Magenta ink cart. This contaminates the bottom of that ink cart. So tonight I printed several pages of color bars that ran for 1/2 of a page. The top 1/2 ink if the Magenta was a mixture of Cyan and Magenta but as the printing continued the full magenta took over and was solid magenta by the middle of the page. Let it sit for 5 minutes and repeat the test and the top 1/4" is still mixed with Cyan. I have taken the ink cart out and forced ink out the exit until only Magenta came out. When I returned it to the printer, clearly there was still some Cyan ink leaking over to the magenta nozzles as the nozzle check showed the magenta nozzles were half Cyan and some magenta. ONly when I print solid Magenta bars do I get full magenta color. So the leak is still there. I also check the pads by the filter screens and there is no excess ink there, just the normal wet filter screen.

The bad nozzles in the magenta color are still as bad as they have ever been. It is clear that the head is not destroyed but the only way to fix the internal leak is to take the printhead apart. I'm not going to do that until I find a way to coat the ceramic such that it makes a tight seal to the rubber.

I do believe that it is possilbe to take the head apart and return it to good condition, if I knew the factory process for doing this and had the materials they use. AFter all the work I have done on different Canon printers I believe that Canon has always designed every part of every printer to be repaired. The are solid printers and easy to service and if you have the parts you can fix just about anything. If you examine the printhead it is also designed to be repaired, that is, certain parts. If you look at the assembly, the entire flex cable, rubber seal, is designed for removeabiliy. That is why the bottom is held on by two screws. If they didn't want anyone to every take it apart they would have thermally welded the parts together. The only thing that we don't know is, "Their process for cleaning it and re-sealing it"
 
How about RTV silicone it can hold up to 300 degrees Celsius head and should seal all leaks, only very small amount on surfaces should fix it. Never tried it myself just thought.
 
Smile,... I imagine the adhesive that Canon uses is very similar to RTV but they probably have a process where they only put 32.5 microns onto both parts that mate with the rubber gasket. If any of your are familiar with engines, the rubber seal is very much like a head gasket, the ceramic nozzle assembly is like the head, and the plastic carriage asm is like the engine block. If any of you have ever blown a head gasket, you know the problems that can happen.

Does anyone know what the cure time is for RTV????
 
Just to update this thread,... If you've read my last two or three posts you know I had problem with the "Boiling" water method and don't recommend it at all. I continue to have internal leaking of ink between the Cyan over to the magenta nozzles and in fact it is wicking back up into the Magenta cartridge and reuning it. Once Cyan mixes with that ink cart it is no good any more, except to set aside and do the 100% flush of it and dry it and try again. The leak inside the printhead must really be bad to traverse al the way through the printhead down to the ceramic and flood the magenta well so much that ink will flow upwards back into the magenta ink cart. It has done this twice and each time I have forced the ink out by blowing into the air inlet hole until all bu Magenta ink comes out. Tonight I check again and the bottom of the ink cart was almost black with the mixture of Cyan and magenta. I was not able to get it all out since it has contaminated so much of the sponge. I replaced it with an empty yellow ink cart that I was not using. I bet tomorrow night it will be black and blue.

I'm only using the black ink any way cause I don't have time to take the printhead out and clean it and set it aside for another day. It is clearly going to have to come apart. It will be interesting to see what damage was done to the rubber seal. So much for boiling water.
 
Eeek... yeah I hate to say it but with hindsight, boiling water doesn't seem like the best approach... Warm water should do just as well... Ah well, we learn from the mistakes of others willing to go forward and try things :)... or we're the ones making the mistakes ourselves ;)
 
Exactly the benefit of this forum, where participants are willing to show their failures as well as successes.
 
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