stainless steel mesh as cartridge medium

[Bertrand]

Som general principles for cartridge material (please correct this if you know any better):
1. Surface tension is the main force you need to manipulate. In other terms, the tendency of a liquid to adsorb to the mesh - low surface tension - vs. the tendency of a liquid to cohere to itself - high surface tension.)
2. Both propylene glycol and glyerine have a lower surface tension than water. I would imagine there would also be an emulsifier in there that would reduce it further.
3. The viscosity of the liquid defines how quickly the forces will act to distribute the liquid. E-liquid clearly has a higher viscosity than water.
4. All things being equal, the eliquid will adhere to the mesh. It will therefore appear to move from areas of lower surface area to areas of higher surface area.
5. If the cartridge mesh is finer than the atomizer mesh, it will tend to pull the liquid out of the atomizer mesh, and vice versa. ("Dry" smoke.)
6. If the cartridge mesh is coarser than the atomizer mesh, the atomizer mesh will tend to pull the liquid out of the cartridge mesh. (What we want.)
7. A cartridge mesh that is too coarse will allow the e-liquid to cohere into droplets large enough that you end up sucking them out through the mouthpiece ("wet" smoke).
8. If the atomizer mesh and the cartridge mesh are not touching, the liquid will not transfer. This is a real problem for all-metal cartridge designs, since the metal tends to permanently deform when pushed down by the atomizer.
9. The mesh right at the top of the cartridge is the most important part to get right if you want to avoid liquid in the mouth (empricial.) My feeling is that probably a coarse mesh underneath and a fine mesh cap at the top would be ideal, but I will need to try this.
10. Using a spring to maintain contact between the cartridge and atomizer meshes only works if you put it between the mouthpiece and the cartridge itself (filing down the ridges in the cartridge). Even here, it tends to squeeze on the cartridge so that the eliquid pools and you get eliquid in the mouth. There may be a spring weak enough that it doesn't cause pooling, but strong enough that it maintains contact.
11. Cartridges work better to begin with (empirical). You cannot use the first few hours of use to evaluate them. Use them at least a day before you evaluate. I presume this has something to do with the mesh surface.
12. You will always cut yourself working with metal mesh.

[bribri]

What about using a piece of that shamwow thing instead of the fiber in the cartridge? that should hold some eliq!

[Bertrand]

What about using a piece of that shamwow thing instead of the fiber in the cartridge? that should hold some eliq!

From what I can see, this is a chamois. Refer to principle 4. It won't wick into the atomizer properly. And it's likely poisonous.

The goals of the cartridge medium are:
1. It provides a fairly steady supply of e-liquid to the atomizer.
2. It does not get e-liquid into the mouth.
3. It empties almost completely.
4. It is easy to refill. (No messing around with syringes, etc.)
5. It is nontoxic. (Nickel poisoning symptoms are very similar to those of nicotine overdose, by the way, so be careful.)

[PeteMcArthur]

From what I can see, this is a chamois. Refer to principle 4. It won't wick into the atomizer properly. And it's likely poisonous.

The goals of the cartridge medium are:
1. It provides a fairly steady supply of e-liquid to the atomizer.
2. It does not get e-liquid into the mouth.
3. It empties almost completely.
4. It is easy to refill. (No messing around with syringes, etc.)
5. It is nontoxic. (Nickel poisoning symptoms are very similar to those of nicotine overdose, by the way, so be careful.)

Update on the pot scourer technology:
Seems to be working well with a penstyle, my first cart seemed to drain almost completely, on refilling I put 37 drops in it. It does not meet your goal 4 however, you don't need a syringe but you do have to remove the top filling layer, not too much of a hassle but could be better.

I'll give it a go on a 901 ASAP however I have the toothache from hell so it won't be today.

[PeteMcArthur]

Well the penstyle is working well, the 901 is less successful. The scourer is just too course work work properly in such a small space. I'll have another go at a 901 but my hopes are not high.

[Bertrand]

Hi Pete,

Just wondering how you did the penstyle cartridge? I don't have one, but am thinking of making a screwdriver adapter if you can modify these cartridges. I've only seen online photos of the cartridge. Is the white part of them a plastic container? (It looks like it might be nylon wool)

I've been going a day on a coarse mesh / fine mesh cap and so far it is very good. (901). You just put the dropper on it, squeeze it out and repeat to fill, it empties completely, and there is very little drop-off in vapour (it just starts tasting bad when it's empty.) I got a slight bit of liquid in the mouth when it started, but as these break in they tend to get drier (it isn't happening any more) so it's probably a good idea to make them a little wetter than you ultimately want.

Another observation I've made is that you need to make the cartridge for a particular kind of e-liquid. I have been using the Johnson's Creek eliquid for the most part (both PG and NPG) and it's been working well with this. I tried using a different brand (thicker) and it was quite difficult to get into the cartridge. Regular cartridge filler doesn't have this problem: they work equally badly with all the liquids, since they only work when completely saturated (I could only get about four drops at a time into a regular dse901 cartridge once it had reduced vapour production.)

And the other thing: the eliquid seems to evaporate when held in the mesh cartridge, since more of it is exposed to air. No big deal really, except overnight.

[Bertrand]

I forgot to mention the way I'm maintaining contact between atomizer and mesh now. I make the mesh protrude slightly further out, so you don't push the cartridge all the way in. This way, as the mesh / atomizer is slightly deformed when removing / replacing the cartridge, you just push it a little further in. I don't know if it'll keep working this way, but it hasn't seemed to move at all, so it's looking good.

[Bertrand]

hehehe.. As Columbo says... there is one more thing.

The VG stuff seems to evaporate less quickly than the PG stuff, if at all much. I will try loading it up with one or the other for a few nights.

[PeteMcArthur]

Hi Bertrand,

One of the reasons with me mucking about with the penstyle is with the aim on eventually getting one on the screwdriver. Like trog I experienced problems with penstyles getting enough juice to the atomiser, but so far the scourer seems to be helping, it is just another way of doing what others have done before.

I'm going to do a couple more and will post pics of how I did it, I'll also put a 901 to show you a size comparison, you'll see just how much bigger the penstyle is. It's wont be today though, 3 days of continual toothache has got me completely dememted

[Bertrand]

Hope it gets better.

I found a source for stainless steel mesh, but so far my cartridge is working quite well, so I don't know if I'll use it:

McMaster-Carr