Sealing the refill hole BCI-6 BCI-3

Goober, careful with those zinc screws. I'd replace them with stainless steel (as noted earlier in this thread).
 
Thanks Rob :) ,

I've had a closer look at the screws I use and they seem to just discolor the color of the ink. It doesn't appear to be rust. Maybe the screws are a particularly good quality. The lighter color ink usually washes off with very hot water with only the black and cyan leaving a permanent stain, these I replace at each refill just in case. The screws I use are actually a self drilling tipped screw for fixing fencing material.

Cheers
Goober :cool:
 
Hello Friends:

Regarding zinc plated screws: As Grandad & Goober suggest, there are a wide range of quality of screws to be found and the following may have limited application. At Rob's suggestion, I have closely examined several zinc plated screws from one of my printers (all from the same lot) that have been in place for 8+ months. All are deeply discolored, almost black, which I recall ocurred almost imediately, but none of them appear to have any corrosion, in the sense of flaking or rough surface. I can't imagine anything from the screw passing through the sponge material anyway. In time, I'll probably join the ranks of the 'err on the side of caution' folks and change to stainless steel screws, but for now I'd simply like to say the sky is not falling.

Best regards to everyone,
Mark
 
Bad news my friends:

I was printing and got some horrible results. After a bit of work I discovered my magenta was leaking. Upon closer examination it seems that my screw / o-ring combo started to leak:

leak.jpg


These rings (in my opinion) are too big, and may loose the ability to seal as well as time goes on, and may be effected by our crazy heat wave (as I mentioned in another thread).

I replaced the ring with a 005 ring that are mentioned earlier in this thread. I will start using these and/or the 004 rings for a tighter fit.

Also of note is that these o-rings are made of neoprene which it seems are better rated for water and alcohol!
 
Rob,

A few comments:
1. It is hard to say for sure from the photo, but it appears that the aluminum foil seal to the left of the O-ring has a groove that is lower than the top surface of the cart and that this groove extends under the O-ring. This could provide a potential air leakage path into the ink chamber.
2. The left side of the O-ring is in a shadow, but it appears that it has been partially pushed out from under the head of the screw. If this is the case, this could also provide an air leakage path.
3. Because these are "static" seals (there is no movement under use), there is no reason not to "crush" the O-ring a little more to push it down into the groove in the foil.
4. As you said, a smaller O-ring will help. Ideally, the O-ring will be a snug fit on the screw shank to prevent it from squeezing out from under the screw head.
 
Good observations Grandad. From pic I wonder how much seating pressure you are exerting on the Oring? I would also guess you are using a pan head screw which don't have a very large dia head. You need to make sure that the head is larger dia than "peak" dia of Oring or otherwise as you tighten the screw you will expand the dia of the Oring. Binding head and truss head screws have a slightly larger dia but it may not be enough. There are speciality screw with "built-in" flat washer which should do the job but find one could be a problem. You would need to contact a fastener dist to see what was available. An alt would be to add a thin SST flat washer under the screw head.

Just remembered, some computer case screws have the washer head design but screw size maybe too large. #4 size if I remember correctly.

Personally, I use rubber plugs without any difficulty or problems.
 
It does seem that the o ring is too large to form a positive seal, but the screw threads may be the real problem of leakage in the first place. The o ring should be a backup seal for tight fitting threads, but this screw looks like it may have a fairly coarse thread which could cause leakage to begin with. The plastic in the cartridge isn't very thick and a coarse thread may actually not seal in places whereas an 8-32 or 10-32 thread would have more contact area.
 
www.tacomascrew.com has nylon pan head screws catalog no. 146-202-2 (#6-32 x 3/8") and o-rings 193-301-1 that I got from a local store for $3.62 ( 20 screws + o-rings).

They fit OEM and BIJC#2 carts without threading tools I screwed-unscrewed them 15 times without failure. I have not yet used them on a cart in a printer.

The ball or plug sealing the ink tank fill hole has to be removed (instead of driven in) to preserve the ridge the screw threads engage.

After further testing it is recommended to thread the ink tank filling hole. Using a 6-32 NC tap about two threads were produced in the ridge supporting the plastic seal plug. With the threads the Nylon srew is easier to install and remove.The scew should be tightened an additional 1/2 to 3/4 of a turn after the O-ring contacts the case to slightly compress the o-ring. The above has been checked with a leak test.

JV
 
Leak test of Nylon screw described in previous Post #118:

1538_Re.jpg


With the sponges removed the cart was filled with water and the nylon screws were installed and thghtened 1/2 to 3/4 turns after the O-ring contacted the cart. The screws were removed and installed 15 times over several days. There were no leaks. This test applies to a OEM cart because the case is identical to the BIJC#2.

On a second case without water the screws were installed 20 times and then tightened two turns several times to check if the threads would strip. The threads held. Upon unscrewing the threads had deformed but were still usable.

The sponges were removed by wraping them around a drill and pulling them out thru the ink exit hole. The tape sealing the air hole had to be glued to stop leaks.

The second srew sealed a hole I had drilled for washing the carts per Grandads new technique.

JV
 
I'd like to throw in my 2 cents on this discussion. I like the idea of using O-rings and sheet metal screws to seal the opening, but it seems a bit big relative to the cartridge size. Here is my idea about that:
You could salvage small screws from electronic devices (CD-ROM drives, boomboxes, etc.) if you have access to junked ones; or if you want to go stainless, you can order some from MicroFasteners. Their page for pan-head sheet metal screws is http://www.microfasteners.com/catalog/products/TWSSMPP.cfm and they have #2 x 1/4" stainless steel screws for $3.60 for 100. Now for the rubber gasket, I think you'll like this idea! Take a rubber glove (not the missus's main pair!) and get a leather punch, the type that has six different hole sizes and grips like pliers. Use the smallest punch size to punch little holes in the material, then use scissors to cut them into little squares. (I was thinking a paper punch would work for this, but did not have success - the rubber wants to stretch through the hole instead of cutting it. I also could not get a clean cut with the biggest size on the leather punch) for a thin and very cheap gasket for the little screws! (I'll have to give it a try and post on how well it seems to work.)

My other comment is that I had purchased some aftermarket BCI-3's that have a single sponge, and it seems to be one that does not soak up ink well at all - a good portion of the sponge had not absorbed ink when I opened them. No brand name on the box - just a rainbow and descriptive information on a white background. I would avoid these if possible (I wont reveal the seller in case they have changed brands since they sold me these.)

I really love my Canon S600 printer, even thought it doesn't have photo inks; I am sorely tempted to pick up an Epson R200 however to be able to print on CD's & DVD's; they seem to be offering good rebate deals on them and I suspect they are being closed out (this weeks Best Buy ad says 'while supplies last').

Very happy to find this forum where we can discuss our ideas for refilling ink.

Ron
 
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