Vinyl works! ...for now. Here is the experimentation so far.
disclaimer 1: this is going to be really long and boring with a lot of rambling.
disclaimer 2: crappy pics -- cell phone which is just as good as my Kodak DC4800. I am absolutely going to buy a new camera after the holidays.
I started out with an acrilic tank. The o-rings were too big or the tube too small. It took extreme pressure to assemble it. It lasted almost 2 days (no knocks, drops, bumps, temperature shocks, etc.).
It's a 510 connector and I decided to go with copper rod instead of wire. Mainly because I thought it would look really cool. and professional. and maybe a bit more rugged and easier to work with on the top end around the kanthal and mesh.
Here is the first effort:
It actually worked!
Notes:
1) The center post in the connector was insulated with a sort of foam (white) gasket which I managed to tear in short order. Good news is that other connectors from old burnt out attys were more durable (gray). Soldering the rod into the center post was easy. The rod fits snug but easily into the center connector.
2) Soldering copper to brass is not easy... especially inside a connector housing that is already pressed into the bottom cap. After some googling in a plumbers forum I found that the brass needs to be hotter than copper needs to be to solder them together. My cheepo plug in soldering iron wasn't cutting it. I've got one of those small butane soldering irons that can be used as a focused torch as well. Plumbers call it "sweating". Throw a glob of flux into there and torch to where it almost burns. Then use liberal amounts of solder. Wash with soap and water, clean up excess solder with a fine point dremel bit.
3) Used shrink tubing to insulate the copper rod where it goes through the top cap. Measure first. Cutting it to length after it's on the copper will make your copper rod look like a hack job.
I filled the inside of the connector with silicone sealer (neutral cure) flush with the bottom of the bottom cap. No chance of any leakage through the center post or aournd the edges.
Here is the business end:
Ok, so I used the "crimp" method of connecting the kanthal. That wasn't the plan. I want some sort of screw or nut connection. Problem is that I only have about 9 mm of headroom inside the top cap/chamber. I didn't find anything small enough to put on top of the copper rod that had a screw or something to affix the kanthal to that was short enough. Still working on that. The crimp only needs to be loosened slightly to change kanthal but eventually its bound to fatigue and break off. I figure I could change kanthal 20 or 30 times before that happens and I'd have to go to soldering it on but I want this to be a lifetime solution and hopefully without having to solder.
That's
14 mm of 400 mesh rolled to about 1.9 mm diameter
0.16 gauge kanthal wrapped 3 full times resulting in 2.2Ω (3.7v Li-Ion)
Oh, yea, I use really thick 100% VG juice
The air hole in the top pic is way too big. Originally it was something like 3/64" and the draw was too tight. Smallest drill bit I had at home was 1/16"... a 1/16" bit looks really small. It's not. I drilled out the original hole and it was like a broken cigarette. doh. BUT, if I just did a direct inhale for about a second and then continued without the genisis it worked pretty well. Kind of like how a .... works (not that I've ever seen anyone use one). Since then I found we have a drill press at work and bits down to 1/25". So I drilled 2 additional holes. I'm going to order a small drill bit set and add a couple more. 1/25" is just a *little* too big for my preference when taking a drag the normal way. Right now I'm using a bit of scotch tape to cover various holes and experimenting with how I want to use it. Plan is to plug the unused holes from the inside with epoxy or something when I settle on the desired option.
Note: EVERYTHING is interdependent and small changes in any or all of the following make a difference. Mesh/wick characteristics, kanthal gauge and length/resistance, juice, air flow, how you take a drag and personal preference on vapor/th/taste/heat.
This was bit weak. It took almost 2 to 3 seconds for the kanthal to heat up all the way and then the result was a bit weak. Yes, if you stayed in it the kanthal would glow. I used it all day at work thinking about changes to be made and how to approach it.
I rolled a couple more pieces of kanthal. 20 mm into a 1.9 mm diameter roll and 30 mm into a 2.0 mm diameter roll (I only have 400 mesh at the moment). Tried the 30 mm roll. When I put the kanthal back on I ended up with 2.0Ω (must have wrapped tighter or crimped more of it for a shorter length). Result was the same but for a completely different reason. Now it would heat up and the mesh would start to spit. It was like miniature solar flares or tiny comets coming off of it. Closer inspection and it looked like juice in the center of the roll was boiling. The juice towards the outside of the roll was vaporizing and the juice boiling in the center spitting out through it.
Then the disaster struck:
It was just sitting on the desk all by itself and I heard this "pop". Looked over there and saw drops of juice forming on the outside of the tank... I still think that maybe slightly smaller o-rings would work. but then there would forever be the fear of reliving the trauma.
I figured polycarbonate would be the ticket. couldn't find any in the right size. Then people here said they had cracked their lexan too -- but I don't think they were using o-rings. I started thinking that vinyl tubing would be pretty stiff in a short length. Home Depot has it in 5/8" ID! Just .005mm too small which shouldn't be a problem since it's flexible. OD was slightly larger so it wasn't going to overhang the caps but... heh, thicker wall might be necessary to hold the seal over time.
Vinyl!
Yea, yea, I know the ends are rough. I just put it together. I'm thinking with a bit of careful torch work I can make it look just like the sides and you won't even see it. It is rigid. It is firmly in place and not a hint of leakage in a day now. I don't think it will ever leak. Problem is that the end caps can be removed pretty easily. Especially with a little side leverage. I don't doubt that the end caps would come out if it was dropped on the floor on the mouth piece end or if you scrunched it by sitting down with it in your front pocket... If I continue with the vinyl tubing I'll try gluing it with silicone sealer. I think that would do it and you could still remove it with a knife if internal repairs were necessary or for very infrequent internal cleaning (although with 2 or 3 days use I see no evidence of anything that might need cleaning in the tank. Maybe over time the oxidation/soot off the mesh might leave some unsightly traces in there?)
Haha, options for changing the draw (more to come)
And here is the business end currently. I may have nailed it this time!
That would be the 20 mm roll with a 1.9 mm diameter. 4 tight wraps resulting in 1.6Ω.
Note: people get hung up on how many wraps there are. Assuming you have a few wraps for some coverage it's the resistance that makes a larger difference. With a fixed voltage that's going to result in a current that's going to give you a wattage that will determine the heat. So it's the entire length and gauge of the kanthal from contact to contact. Sure the amount of wire in proximity to the juice is a factor but on this last attempt I got 4 wraps and ended up with less resistance than my other two variants with 3 wraps.
This time the result is outstanding! (for me). It's working great with both drag methods (haha, cigarette drag method with a small air hole or .... hit method with all holes open).
I'm really stoked. This is what I've been looking for. A permanent atty/carto that's completely user serviceable and can be customized to your current preferences. Kanthal and mesh are about it, and right there out in the open on top.