How NOT to fail with the German Refilling method

[panos]

ghwellsjr, thanks for your post.

I accept that some of my pointers are not in the original announcement. They don't modify it but they restrict it a bit. They were formed as safeguards against my natural tendency to experiment and I knew that some other participants in this forum would find them useful because the vast majority of us have a tendency to experiment.

But I always thought that the type & size of the needle, the position of the hole and the injection location were not suggestions but rules in the original photos & videos. I did not follow the debate that ensued after they were published.

I agree that the instructions of the method should be made more clear, at least on the needle and the hole and not rely on imagery only. As you and Pharmacist have made it to the official nifty article I hope you'll come to an agreement on how to present the updated rules.

I'll PM Pharmacist to take a look at this.

 

[barfl2]

Like a lot of people I thought the hole at the bottom was the recommended position. To start with I had problems finding the elusive port into the ink resevoir. To try and make it more scientific I took a compatible apart (could not spare an original) and measured it. externally it was identical every Canon moulding items were there even down to the ink maze, ink grooves and the hemispheres. The case thickness was 1/16". With this in mind I prepared a drawing to show the hole position centred, and allowing for a 20G needle.

I printed out this template, stuck them on my carts and drilled my hole. First with a .0.024" drill followed by 1mm. Now all my needles go straight along the bottom and more importantly straight through the middle of the port into the resevoir. My only problem is like Rodbam I did get some ink into the maze but I deduced this was because my blunt needle was stuck against the prism, and I was applying undue pressue to the squeezy bottle. I solved this by fitting 1/4" sleeves (from electrical cable) onto the base of the needles.

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The main point of this post is that I feel a lot of Forum members are using the bottom hole method and if they are having no problems stick with it. Websnail raised an interesting point about possibly raising the sponge. Would the firm TAP suggested by Grandadl overcome this possible problem ?.

Finally thanks to Panos for raising a very interesting post which was offered for the best of reasons, to help others.

barfl2

 

[pharmacist]

So just to break in this rather interesting discussion about the do's and don't about the Durchstich refill method. Actually I do no think it is very important if the needle is going exactly underneath the sponge or not. I am trying to do so every time, but sometimes I just pierce through the sponge material. Note: I only use sharp needles, since I do not have any blunt ones (the ones supplied with my Hobbicolors UW-8 refill kit are gone and missing) and like previously mentioned: if you feel any resistance just pull back and try again and sometimes one needs to rotate the needle to drill your way into the ink compartment.

Is it 100 % hit on every time, no but it does the job far more reliable then the top filling method, which happened to stain my fingers and table desk every time, when the ink leaked out from even tightly sealed (which I thought so) cartridge.

So I might upload a video demonstrating how I am performing this refill method on youtube, to clear things out.

 

[ghwellsjr]

Websnail raised an interesting point about possibly raising the sponge. Would the firm TAP suggested by Grandadl overcome this possible problem ?.

This may help but the problem is that the so-called sponge is not really a sponge in that it may not return to its original shape if you deform it. There can be a permanent grove in the sponge material acting as a channel through which ink and air can readily flow. That's why it is important to make sure that grove only goes a short way from the hole at the bottom of the reservoir toward the outlet port but not including the outlet port. You don't want that grove to exist between the refill hole and the outlet port. And the way I make the hole with an awl, you can even see that grove in my videos. I don't think this will be a problem if the hole is made above the bottom of the cartridge.

Those people that have only used sharp needles cannot really appreciate the difficulty of getting a blunt needle into the reservoir hole or the problems that are created by using a blunt needle. That's why I think the point panos is making, that putting the hole at the bottom which is required when you use a blunt needle are not really the German refill method but rather a modified German refill method and the resulting problems should not be blamed on the German method.

 

[ThrillaMozilla]

Your post was very clear, and correct, I think. There's just one little thing.

I was not the least bit concerned about a leak because if there were any possibility of a leak, it would be more likely to go out the outlet port and we know that doesn't happen.

You probably meant that as part of the narrative on what went wrong, but it might be worth pointing out what's wrong with the reasoning. Leaks are blocked at the refill hole by at the sponge and at the outlet port by the filter. Ink will flow through either if there is sufficient pressure to overcome capillary action. But the sponge and filter are two different materials, with different (unknown) capillary properties. More importantly, the refill hole leaks only if there is a path for leakage around or through the sponge, but there (hopefully!) is no path for leakage around the filter. Furthermore, the filter is connected to the print head and all the equipment connected with it.

So comparisons between the exit port and the refill hole don't seem applicable in this case. What is important, I think, is just to make sure the refill hole cannot leak. And that means placing it above the bottom of the sponge, and if you really want to be safe, higher than the top of the opening between chambers.

 

[ghwellsjr]

Your post was very clear, and correct, I think. There's just one little thing.

I was not the least bit concerned about a leak because if there were any possibility of a leak, it would be more likely to go out the outlet port and we know that doesn't happen.

You probably meant that as part of the narrative on what went wrong, but it might be worth pointing out what's wrong with the reasoning. Leaks are blocked at the refill hole by at the sponge and at the outlet port by the filter. Ink will flow through either if there is sufficient pressure to overcome capillary action. But the sponge and filter are two different materials, with different (unknown) capillary properties. More importantly, the refill hole leaks only if there is a path for leakage around or through the sponge, but there (hopefully!) is no path for leakage around the filter. Furthermore, the filter is connected to the print head and all the equipment connected with it.

So comparisons between the exit port and the refill hole don't seem applicable in this case. What is important, I think, is just to make sure the refill hole cannot leak. And that means placing it above the bottom of the sponge, and if you really want to be safe, higher than the top of the opening between chambers.

Actually, no, I didn't think there was any possibility of a leak until it happened. Your reasoning is spot on. Also your illustration and analysis in post #36 are very good.

So the question is, how high up should the refill hole be? I'm thinking the best place would be right under the ledge that is used to hold the cartridge in place. Any opinions?

 

[irvweiner]

A simple suggestion: The use of a fine sharpening stone will easily convert a blunt needle to a sharp and vice versa.
Do clear the small shards of metal that cling after reshaping.

irv weiner

 

[panos]

A simple suggestion: The use of a fine sharpening stone will easily convert a blunt needle to a sharp and vice versa.
Do clear the small shards of metal that cling after reshaping.

Yes, I think that'll work. Perhaps inserting a hard metal wire inside the needle before cutting it would prevent the edges to bend. Filing / smoothing the edges after cutting would be mandatory, yes, otherwise the tip of the needle will act as a barb inside the sponge.

 

[martin0reg]

As five out of seven "don't" are at least controversial -
I consider this a helpful approach:

The stages are:
1. During refill - failures: ink going above sponge and into air maze, ink leaking out along the needle
2. Long term storage- failures: leaking, evaporation
3. During use - failures: ink starvation, leaking

Parameters:
a. hole placement - values: near bottom, at distance from bottom
b. needle - values: blunt, sharp, thin, thick
c. seal on hole - values: no seal, adhesive tape, hot glue
d. cartridge empty before refill - values: yes, no
e. topping - values: yes, no
f. saturating upper sponge - values: yes, no

Most combinations are neutral with parameters balancing each other, or with limited impact in only one stage, but:
- The worst combination I think it is: a. near bottom, b. blunt and thick, c. no seal, d. no, e. yes, f. yes, can result in a full mess, in all stages.
- On the other side, the combination: a. at distance from bottom, b. sharp and thin, c. hot glue, d. yes, e. no, f. no, is a winner.

My experience:
a. I use to drill ca 2mm above bottom, seems to be the classical placement. Bottom can be okay too, potential issues in discussion, it depends also on the needle type. More important is to overcome the ridge at the entrance to the ink chamber (see b.)
b. I use to refill with blunt needles. But you have to avoid squeezing the sponge!
If the needle does not manage to pierce a virgin sponge, I use a sharp needle and try to control direction by turning the syringe. Later I refill with blunts (on websnails squeeze bottles) as they follow easy the channel and won't cut a new wrong channel.
c. To prevent evaporating (or wrong air flow) I would seal the hole with adhesive tape. If the cartridge will be refilled again frequently, sealing becomes more redundand. To avoid wicking of ink to the tape cut a clean edge of the hole and use new tape.
d. Should be possible with caution (see f)
e. + f. interdependends: I try to refill the ink chamber nearly full. But the upper sponge should NOT be saturated (avoid by any means ink going up the air maze)! If it does, you have to flush or recondition the sponge - or take a new virgin cart.

 

[Redbrickman]

Martin,

The point you make about the air maze is very valid. I lost concentration when topping up the reservoir, and ended up with a cart too full and ink in the maze

If that happens best plan is to suck out as much of your precious ink as possible with the syringe/SquEasy bottle, then flush the cart.

2mm above the base of the cart is where I drill, and with a 20g needle I have not had any problems.