Needle length for German Durchstich refill method

[stratman]

Pharmacist:

It is good to know that Hobbicolors is a source for appropriate length needles. Thanks!

I see the logical desirability of using sharp needles. It makes intuitive sense as compared to using a blunt needle. But my own experience is that an 18 guage blunt needle works perfectly. I use a standard push pin to make the refill hole, which might additionally pierce the sponge and act as a point of advancement for the blunt needle. I have never used a sharp implement to make a first pass through the sponge.

The one and only malfunction I have had was after refilling an older empty PGI-5 cartridge without purging it first - ink would not flow. This was not a failure caused by the refill method. Other than that I have had zero problems with 10 cartridges and multiple refills.

I doubt I am unique in my methods or results. I use the push pin to make the hole between the two arrows that face one another at the bottom end of the side wall of the sponge side of the cartridge. I rotate the push pin tangentially to enlarge the hole to help make it easier to initially insert my 18 guage needle. Using the blunt needle on a syringe, I insert and immediately angle the needle towards the bottom of the cartridge (the cartridge is turned upside down during this, so the bottom end is actually facing upwards) while pushing the needle forwards and turning it partially clockwise-counter clockwise at the same time to sort of "cork-screw" the needle along. The blunt needle will go through the sponge and hit the bottom of the cartridge well before reaching the hole between the sponged and non-sponged sides of the cartridge. I just refilled a cartridge and the needle tip was visible immediately past the ink exit port. So, very little of the sponge is actually pierced. From here, the needle is advanced to and through the hole adjoining the two sides of the cartridge. The needle tip eventually hits into the tiny plastic piece at the bottom of the spongeless side, acting as barrier to further needle advancement. I then retract the needle slightly away from this barrier and begin injecting ink. Subsequent refills use the track formed from the first needle pass.

The purpose for my posts was not to say you or anyone else must use a blunt needle. I only want others, especially those desiring to use the Durchstitch method for the first time, to not despair if they cannot find sharp needles since a blunt needle as large as 18 guage works perfectly fine without any extra effort to prepare the sponge. The only true potential obstacle known to me at this time is obtaining needles of sufficient length. Fortunately, this appears to be a non issue for most other than their willingness to pay premium prices for shipping and taxes depending upon location. Has anyone been forbidden by law to have a 50mm/2inch or greater blunt needle?


***Angiocaths (too fragile?) and extremely large bore needles (too big a hole leading to leaks?) may or may not be appropriatel. If anyone has experience with these, please post.***

 

[yupkime]

I am sure everybody knows how it works but here are some pictures of the alternative method which works too with less potential sponge damage but some sponge saturation.

If using this method, just keep checking the amount of ink saturating the sponge and "milk" it (squeeze some out) if too much gets in.
I've experienced no leaks and it is easy to cover the hole that is made if you want to.

However, having obtained the right length 2" x 21g needle, I think I am going to stick with the German Durchstich method because of the previously mentioned reasons that it looks better from the top and the 21g needles have absolutely no problem going through/underneath the sponge. It fills up only the ink chamber side with no sponge saturation.

With an 18g needle, I had some reservations with sponge damage and movement, but if you get a thinner needle then there should be no problems.

However, I found I had alot more difficulty with aftermarket ink tank cartridges using the German Durchstich method in that it was harder to get the needle to the other side consistently, sometimes never, due to sponge/cartridge design I think.

Refilling Canon OEM cartridges are the best and easiest by far. Works everytime. It seems the sponge quality and 2 piece construction is better too than aftermarket.

If I had only aftermarket cartridges then I would probably use the traditional top fill hole method since most of those have an easily removable/replaceable plug designed for refilling.

Hope this helps!

My pharmacist friend was able to find these 2" x 21g long needles for me so if you are in Canada then let me know and I can send some to you at close to whatever the cost is. Really hard to find apparently!!

 

[Tin Ho]

Tin Ho,

What about the air breathing hole, does this method impair the pressure balancing inside the cartridge ?

Pharmacist: The quick answer is no. The new hole only add one more vent or enlarged the original vent. It makes absolutely no difference to the pressure balance in the cartridge. I once cut off the entire top of the sponged chamber and the cartridge still worked. It could lead to faster drying of ink in the sponge but I used it for a few days without problems. I did that just to take the sponge out to satisfy my curiosity about the it.

 

[Tin Ho]

Yupkime: Great job! I promised to post some photos but I wasn't sure when I would be able to do it. Thanks!

There is a small trick that will be very helpful in using the American method. I found that if you try to refill a cartridge in which the sponge is still pretty full of ink it may be more difficult to refill. For every drop of ink injected (and dropped) into the reservoir tank it will force same volume of air out. This air needs to have a path to escape from the cartridge. If the sponge is still pretty full of ink the air has no easy way out. The internal pressure of the ink cartridge will build up. This is easy to understand. When ink is injected into the cartridge the internal pressure will naturally increase unless air can escape from the cartridge. But if the sponge is full of ink there is no air passage for the air to escape. The increased pressure will cause ink to spill out of the vent and the new fill hole. It will spill out of the large ink outlet too if it is not covered. I think this trick is usefull for the German method too.

This is when the difficulty will begin. Ink may not want to go into the reservoir tank freely any more. This may be why you can only fill up a small portion of the reservoir tank. What you can do is before begin to refill you actually want to use an empty syringe to suck as much ink out of the sponge as possible. This replaces ink with air in the sponge. This leaves the sponge plenty of air passage when you begin to refill. If you refill slowly the sponge will not begin to absorb ink until the reservoir tank is pretty full. At that point you can continue to refill and let the sponge to be saturated with ink. Just don't over saturate it. You can use a tape to tape over the fill hole. You don't have to. But it helps to reduce ink drying from the hole.

 

[NickC]

Further thoughts on refilling these cartridges.

1). The rememoving the ball and injecting directly into the resevoir method is not perfect because the hole cannot reliably be resealed after filling.
2). The original Durchstich method is not perfect because it means perforating the micro-porous foam near the sensitive outlet hole.
3). The alternative (see yupkime post above) method is not perfect because it tends to saturate the foam rather than putting the ink directly into the resovoir.

Nicks Durchstich mkII method:
Use a small but long needle say 20gx3" from the top rear of the cartridge at 45deg through the foam directly into the bottom of the resovoir. That way - no damage to the sensitive part of the foam, no foam saturation, no hole below the ink level. Can anyone see a problem with this method?

 

[Ron350]

NickC

Nicks Durchstich mkII method:
Use a small but long needle say 20gx3" from the top rear of the cartridge at 45deg through the foam directly into the bottom of the resovoir. That way - no damage to the sensitive part of the foam, no foam saturation, no hole below the ink level. Can anyone see a problem with this method?

I was thinking about the same thing have you tried refilling like this yet?

The top section on the back is a smooth surface so you could seal the hole with tape is so inclined.

 

[pharmacist]

Further thoughts on refilling these cartridges.

1). The rememoving the ball and injecting directly into the resevoir method is not perfect because the hole cannot reliably be resealed after filling.
2). The original Durchstich method is not perfect because it means perforating the micro-porous foam near the sensitive outlet hole.
3). The alternative (see yupkime post above) method is not perfect because it tends to saturate the foam rather than putting the ink directly into the resovoir.

Nicks Durchstich mkII method:
Use a small but long needle say 20gx3" from the top rear of the cartridge at 45deg through the foam directly into the bottom of the resovoir. That way - no damage to the sensitive part of the foam, no foam saturation, no hole below the ink level. Can anyone see a problem with this method?

yes there is, but a practical one: You'll need a 3" (maybe 2.5") instead of a 2" needle to accomplish it. And this would be even more difficult to obtain. The perforation of the sponge material near the ink outlet hole is negligible, because some guy at druckerchannel.de tried piercing the material several hundreds times with a needle and it still seems to work without any hiccup.

 

[NickC]

Nah, shouldn't be a problem, vets use needles that long. Maybe not cheap but should be available. Will revert when I have actually obtained one and tried it.

 

[wizzard]

Nah, shouldn't be a problem, vets use needles that long. Maybe not cheap but should be available. Will revert when I have actually obtained one and tried it.

I guess price may be the deciding factor.

 

[pharmacist]

NickC,

Price is still acceptable for these needles. Other forum members (especially in some states in the USA) can hardly get sharp needles without any medical prescription. I presume you live in Europe like me and for me especially, I can get these ones from my own shop. That is why I mentioned it as a practical problem for our members here in the USA.