Basic RBA knowledge help me out.

[Silense]

Hello ECF,

So I currently got my first RBA, the RSST. I run it on a pro-vari mini atm because I don't have a mech mod yet. I bought 500 SS mesh and kanthal 30 a1 wire. I am to the point where I know how roll a wick and the basics of wrapping coils etc... At first I was having some vapor production problems, it being on the low side. I recently drilled a hole in the air hole to make it a tad bigger and that seems to be working fine. I have a few questions and I hope you can help me out.

About how much mesh would you use for a SS wick on a RSST. I bought these pre-made 2x2 squares and just roll the whole thing into a wick, problem is even as tight as I seem to possibly be able to roll the wicks it seems i cant fit the whole 2x2 square in the wick hole.
I have to trim just a tad off to make it fit, and of course i already trim the rolled wick to be pretty much even with my positive post.

Second question is I have heard that more coils = more taste ( I may be wrong). But when I seem to do about a 5-6 wrap, my wick/coil is only reading at best 2.0. How do people get them so low to like .5-.7. Do more coils = less resistance? Do those people with such low readings just roll absolutely tight/perfect wicks?

Also I seem to be having a bit of wicking issues. THe first mesh/coil I made seemed to wick just fine but me being new and trying to roll more to get better at it it seems I am getting a very metallic taste about a quarter of the time. I do of course tilt my PV to let gravity do its thing.I am guessing this metallic taste is a wicking issue (again, may be wrong).

I hope all this makes sense and any and all tips from you RBA vet's would be awesome. I am definetly not ready to give up on RBA's, I hear they are the best and I am sure thousands of you aren't wrong.

Thank you!

-Silense

 

[Silense]

Helpage Bump

 

[d3mon]

Hello ECF,

So I currently got my first RBA, the RSST. I run it on a pro-vari mini atm because I don't have a mech mod yet. I bought 500 SS mesh and kanthal 30 a1 wire. I am to the point where I know how roll a wick and the basics of wrapping coils etc... At first I was having some vapor production problems, it being on the low side. I recently drilled a hole in the air hole to make it a tad bigger and that seems to be working fine. I have a few questions and I hope you can help me out.

About how much mesh would you use for a SS wick on a RSST. I bought these pre-made 2x2 squares and just roll the whole thing into a wick, problem is even as tight as I seem to possibly be able to roll the wicks it seems i cant fit the whole 2x2 square in the wick hole.
I have to trim just a tad off to make it fit, and of course i already trim the rolled wick to be pretty much even with my positive post.

Second question is I have heard that more coils = more taste ( I may be wrong). But when I seem to do about a 5-6 wrap, my wick/coil is only reading at best 2.0. How do people get them so low to like .5-.7. Do more coils = less resistance? Do those people with such low readings just roll absolutely tight/perfect wicks?

Also I seem to be having a bit of wicking issues. THe first mesh/coil I made seemed to wick just fine but me being new and trying to roll more to get better at it it seems I am getting a very metallic taste about a quarter of the time. I do of course tilt my PV to let gravity do its thing.I am guessing this metallic taste is a wicking issue (again, may be wrong).

I hope all this makes sense and any and all tips from you RBA vet's would be awesome. I am definetly not ready to give up on RBA's, I hear they are the best and I am sure thousands of you aren't wrong.

Thank you!

-Silense

my comments, the best i can:

1.5x2 is what i roll for my 400 mesh wicks and after i wrap my coils, i trim the top off flush with the pos post screw.

you're provari wont do sub ohms. but to get sub ohms, use 28 awg with a 3/4 wrap. bam, .9 ohms.

i use 30 awg for my provari, but i do 3/4 wraps to get a nice 1.3-1.5 omh range.

when you get your wick wrapped and oxidized and angle cut on the bottom, you should concentrate more on your coil build. try a good 3/4 with that 30 awg. work the coils to get a nice, even glow (EVEN ON THE BOTTOM ONE). wrap it good and close, but dont YANK on the wire to get it super tight. you want it contacting, but not choking, the wick.

here's a "backwards" wrap

meaning i started my wrap from the inside of the wick. now i start outside, but finish INSIDE on the pos post.

 

[mad maori]

you dont want wick too big- it should fit in wick hole easly- if its too tight you will have wicking issues- wick shoul almost drop in- also try taking out fill plug when you vape!!!! - less wraps of wire the lower the ohm's - try going for 1.5 ohm!!! you cant do sub-ohm on a provari anyway.. sub ohm is a whole differant thing-you need a mech mod for that.. i dont know what the amp limit is for provari but 1.4-1.5 im sure will be fine and should give heaps of vape!!! maybe start out with 32g 3-4 wraps and see what you get!!! i can go as low as 1.1 on my evic-any lower and i get short code!!

 

[mad maori]

yea - what d3mon said too !!!!

 

[UncleChuck]

Thicker wire = lower resistance

Shorter wire (less wraps) = lower resistance.

So using 28ga, at say 3/4 wraps gives a resistance from .6-.8 depending on coil diameter (the larger diameter the coil, the more wire used for given wraps, so more resistance)

The main thing with performance is coil temperature, and surface area. You can only increase coil temperature so far before the juice just gets too hot. If you want better performance, you have to start increasing surface area. This means either more wraps (which then must be powered by higher voltage) or thicker wire, since thicker wire has much more surface area than thinner wire.

This is why any atty on the market will fry at 25 watts, yet we can build 25 watt rbas with 26-28 kanthal and get excellent performance. Because the coils in factory products don't have enough surface area, so the coil gets too hot. Running a LR carto might actually produce higher coil temperatures, but less flavor and performance because there isn't enough surface area.

It's a balancing act between coil temp and surface area. If you increase the surface area, at the same power level, you decrease the temperature. If you decrease the surface area, at the same power level, you increase the temperature. When switching from SR to LR cartos on a low powered device you see a performance increase because the SR coil wasn't operating at optimum temperature in the first place. But if you try to crank the power up with an LR atty, you start burning juice because the coil temperature is already at the right spot, the only way to increase performance at that point is by increasing surface area.

That might sound a bit complicated, sorry

 

[Silense]

Btw D3mon that wrap is freaking beautiful. I wish I could get mine like that. It's a bit ghetto ATM. And I think I got the answers to most all of my questions though slightly confused on the whole surface area thang. I really appreciate the help guys. I am not giving up on these RBA's.

 

[Silense]

UPDATE. Well I tried a 4/3 coil and cut a diagonal cut at the bottom of the wick and the thing is working beautifully. No metallic taste, pretty good amnt of vapor and a great throat hit. Also it's sitting at 1.5. So thanks alot for help guys, crazy how such little things make all the difference. Also I did where I started on outside and finished inside. Seems to also have done the trick.

 

[UncleChuck]

Btw D3mon that wrap is freaking beautiful. I wish I could get mine like that. It's a bit ghetto ATM. And I think I got the answers to most all of my questions though slightly confused on the whole surface area thang. I really appreciate the help guys. I am not giving up on these RBA's.

To increase the amount of liquid being vaporized (which is how you get massive tasty clouds) you have to increase the surface area available to vaporize that liquid. One square inch of surface area at 400 degrees (random temp, probably not accurate) won't vaporize anywhere near the amount of juice as five square inches at the same temperature.

Now, if you are stuck with one square inch of surface area, you can increase the temperature, from say 400 to 450 degrees to slightly boost performance. But you can't do this too much, as you will eventually burn the juice if you keep increasing the temperature.

The real way to improve performance is increasing surface area, with the caveat being that you must still maintain optimal temperature of the coil. Increasing surface area without increasing power will lower your temperature, so you have to take both temp and surface area into account, this is why numbers like wattage don't really tell any story at all, they simply are a good way to measure overall power being used, but it says nothing about HOW that power is being used. 15 watts on a carto means something totally different than 15 watts on a 28ga built coil.

Basically, if you were trying to fill your house with steam by boiling water on the stove, which works better? Turning a single burner on high, or using ALL your burners at a slightly lower setting. 4 pots boiling away will vaporize more water than a single one that's a bit hotter. Just like a coil with more surface area will vaporize more juice than a much smaller one at slightly higher temp.

Adding more pots to your stove is like adding more surface area to your coil. You dramatically increase the POTENTIAL for vapor production (and therefore flavor and TH) but you still need to power all those added pots. If you are boiling one pot of water and using 100 watts of power, using 4 pots at 25 watts won't cut it, you need 4 pots at a power level close to the single one to take full advantage of the performance available from that much surface area.

Once I can find some good specs on diameter of different wire sizes I'm going to actually do the calculations and figure out the difference in surface area between 28ga and 30ga. Try to see if it matches the real world figures of my builds, in respect to the amount of power I'm using per sq. in. of surface area. The calculations should work out to a similar amount of power being applied per sq. in. of surface area. regardless of wire type. Since my 30ga builds obviously will have less surface area, and I run them at a lower overall power level than my higher-surface area 28ga builds, it should make sense.

Although there is probably some sort of non-linear relation between surface area and guage of wire, I guess I'll figure it out. Plus then I can say I like to vape at 11watts per sq in of surface area (or whatever it would be) it would be the most quantitative and accurate expression of vaping style to date Simply saying I like to vape at "xxx" watts just doesn't cut it anymore!

 

[Silense]

So your saying with a "fatter" "tighter" wick will increase my vapor production to a optimal level? Meaning I will have to get mesh not in a set square and cut it myself and just roll a super tight wick. I think im understanding you. May not though lol.

 

[UncleChuck]

So your saying with a "fatter" "tighter" wick will increase my vapor production to a optimal level? Meaning I will have to get mesh not in a set square and cut it myself and just roll a super tight wick. I think im understanding you. May not though lol.

Well, I'm trying to explain the concept behind it, not really specific rules. Kind of like the difference between simply referencing the ohms-voltage vaping chart and actually understanding how all those factors work together. Once you understand it you'll be better off than simply following "vape rules"

A tighter coil, meaning the wraps are close together to the point of touching (or appearing to touch) will usually increase performance, this is the idea that the micro-coils work on. Being so close together and bunched up they turn into a little singular furnace instead of a spread out heated wire.

A fatter wick (and coil) meaning a larger diameter, will simply give you higher resistance, or the same resistance with less wraps. If you wrap a wire around a larger diameter object (wick) you will need more wire to wrap around a larger object. So the thicker the wick, the more wire it takes to wrap around, which means you will have less wraps for the same resistance, or more resistance for the same number of wraps.

From a purely numbers perspective, there is no difference between using a larger diameter coil with less wraps, or a smaller diameter coil with more wraps if the resistance is the same. But from a real world perspective, smaller diameter will probably work better, but the diameter of the wick and coil is something that doesn't usually vary TOO much, so I just left this out of my initial posts. And getting diameter too small comes with it's own issues, so like everything, it's a give and take.

The reason I can't simply say "product or method A will give more vapor" is because everything works together.

I can't say a 28 ga coil will increase vapor, because if you under power it, it won't.

I can't say .6ohm coils increase performance, because if you build one with 34ga wire, it won't.

You have to take ALL the different variables into account to tailor the vape to your liking.

Personally speaking, I find the best performance with a 28ga kanthal coil, 4wraps or so at around .7ohms, on standard batt voltage, with touching (or close to) coils. This gives me around 20 watts of power and thick tasty clouds.

For builds I plan to use on regulated devices, I find the best performance using 30ga kanthal, touching wraps, at about 1.5ohms ran at around 5 volts. This is usually around 16 watts of power.

The 30ga builds have less surface area, so it makes sense that the perform better at a little lower power. I start burning juice if I go much above 5 volts, so that tells me I'm close to hitting the ceiling of how much power I'm pumping in there, vs how much surface area exists to deal with that power. The 28ga builds have more surface area, and therefore I can pump more power into them without burning the juice, and am rewarded with increase vapor and TH.

Having tight, uniform, touching (or appearing to) coils goes a long way to get optimal performance, at least in my opinion. When doing a cap-off juice burn to check for hotspots, close coils pump out vapor like there is a fan inside the PV. Loosely spaced ones just sort of have the vapor billow off the coil. Getting coils perfectly tight and uniform is a personal obsession of mine so I might be going a bit overboard.

A car analogy might help, if you are into cars.

You can supercharge or turbo a car, but if you don't increase the fuel delivery, you won't get big performance gains. Just like I can increase coil surface area, but if I can't power that additional surface area, it's useless to me.

You can increase fuel delivery to a normal engine, but if you don't build an engine that can actually USE that additional fuel well, you won't get big performance gains. Just like I can increase the voltage to a coil, but if that coil can't use that additional voltage well, it only causes problems.

A bigger fuel pump won't give you 50HP gains, and an untuned turbod car won't give you huge gains. You need to match the fuel supply to the fuel demands of the motor, when they are in perfect harmony you get optimal performance.

 

[Silense]

Ok makes perfect sense now. THank you so much for the Vaping 101 class. Really helps. I will try another coil roll tonight and get the coils very close and see how that works out.