RDA Trouble with Wismec Indestructible at high wattage

[digitalepiphany]

In addition to some RTAs I have, I've also been trying to get my Wismec Indestructible RDA to work at a decently high wattage.

So far, I've built my own coils (kanthal) and bought some pre-made (also kanthal). The ones I built came in at 0.42 ohms. The pre-made ones were around the same. I use a Wismec Reuleaux RX200, which runs at 9V max, and is supposed to be capable of 200W (not that I want or need to vape that high). Theoretically, using my 0.42 ohms coils, I should be able to vape at 196W.

I use max VG juice, and have tried these coils with several different juices. The juices I use work just fine with my RTAs at 70-80W, but I can't even get my RDA to that wattage without it burning.

The only variable I haven't tested for is the cotton that I'm using. It's Japanese organic cotton strips, but I cannot remember the brand off-hand.

My goal is to DIY my own juice, using my RDA to test the juices I make so that I'm not wasting $5 for a new atomizer in my RTAs every time I make and test a new juice.

So, if you've gotten this far, is there anything you'd suggest I try? I've pretty much given up on my RDA at this point, but I really need to get it to work for me.

tl;dr - Wismec Indestructible RDA with 0.42 ohm kanthal coils on a 9V, 200W regulated device. It should be capable of running at 196W, but it burns my juice even at 70W. Any idea what I'm doing wrong?

 

[sonicbomb]

Firstly you say burning your juice, do you mean you are getting a dry hit?
At any given coil heat the airflow and wicking have to be able to keep up or the coil will get to hot.

• Improve the efficiency of your wicking. Should be firm but not too tight in the coil, wicks should just touch the deck, the juice well should not be stuffed and there should be space under the coil.
• Increase airflow.
• Make sure the coil is optimally placed in front of the airflow and slightly above.
• Decrease the VG content.
• Decrease the heatflux of the coil by building larger coils with more surface area. This may result in a higher resistance. but this does not matter as on a regulated device the coil resistance is not important as long as it is within he operating limits of the mod. The coils I have run above 60 watts are either parallel or claptons.

 

[digitalepiphany]

wicks should just touch the deck, the juice well should not be stuffed and there should be space under the coil

Make sure the coil is optimally placed in front of the airflow and slightly above

I'm going to try these suggestions, and see how it goes. Thanks for the tip. I'll keep this thread updated.

 

[sawlight]

More power need more airflow and more juice flow, otherwise it's no good. If it's good at 70-80w why the need to go to 196? Do you run your RTA's this high? Why not try to set it up so it resembles your RTA's so you get a truer idea of what the juice will taste like when you are actually using it?
I use tight draw RTA's, Kayfuns etc, and when I want to sample juice I use a tight drawing RDA around the same power as my RTA. When I build something crazy I don't taste much, just get a stiff cough and a lot of vaper.

 

[digitalepiphany]

If it's good at 70-80w why the need to go to 196?

As I said above, it should theoretically go to 196W with the resistance of my coils. But, I don't want to vape that high. I want to stick around 70-80W like I do with my RTAs.

 

[bwh79]

tl;dr - Wismec Indestructible RDA with 0.42 ohm kanthal coils on a 9V, 200W regulated device. It should be capable of running at 196W, but it burns my juice even at 70W. Any idea what I'm doing wrong?

The device will pump out 200W (or 196 in your case) just fine. What you do with all that power is up to you. I suggest you spread that heat out -- make a big fat coil out of the thickest wire you have available. Then make another one, and dual 'em up. .4 is rather on the high side for that much power (I use dual coils at .5-ish ohms, and I only run them at about 40 watts or so). If you want to handle all that power efficiently, you're probably going to shoot for a lot lower, like around .1 or so. Don't worry, the Wismec can handle it, just make sure you are using very good batteries if you're going to stress them like that (200 watts is 66.6 watts per battery -- or 22.2 amps -- at low-voltage cutoff, which is higher than the safe CDR of 20A/60W that most of our batteries are capable of.)

 

[johntheshredder]

i have an indestructible and it has been notorious for shorting at the leads, see if its getting hot spots on the back side of the positive post and negative slot where the leads are sticking out

 

[johntheshredder]

also, the only time I vaped at over 150 watts, I had a framed stapled alien, four wraps at 3m id, with about eight ply of 0.3mm ribbon for the center and 26g for the frames, 32 g for the wrap, it ohmed out to .08 and 180 was getting too hot

 

[digitalepiphany]

Well, like I said above, I really just want to get it to work properly at 70-80W. Once I get that down, and can get it to work properly every time, then I might consider exploring other options for coils so that I can go higher than 100W.

I'll check the leads and see if they're getting hot.

My batteries are Efest 18650 3000mAh, with a discharging current of 35A, so I think I'm good on that front.

Honestly, I just got RX200 for the battery life. And sub-ohm capability of course. But, I never figured I'd actually use the full 200W (that's more of a novelty, really). And, the batteries last me almost 3 days before I have to change them, with no noticeable drop in vapor production.

 

[bwh79]

My batteries are Efest 18650 3000mAh, with a discharging current of 35A, so I think I'm good on that front

Those are really only 20A CDR cells, not 35A like advertised. See Mooch's blog for more info:

Battery - mAh - Mfg CDR - Actual CDR - Max continuous amps
Efest purple - 3000 - 35A - 20A - 25A

 

[muzichead]

First things first here.... "NO RDA" is going to vape the same or even in the same ballpark as any RTA. Second is that if you are not using the same exact coils, (type of coil), and wattage you will get different results... Change the environment and the whole vape changes. Just because a device goes to 200w doesn't mean it is vapeable at 200w!! Third and most importantly, if you think your Efest batteries are 35amp, you have been grossly misinformed by someone!!!!

 

[digitalepiphany]

Thanks for the heads up on the batteries. So, I guess there are no 3000mAh batteries that truly go to 35A?

Again, like I said before, I don't want to vape this thing at 200W. I pointed out earlier that if it should be capable of 196W, then why was it burning at 70W (which is the wattage I'm aiming for). I'm pretty sure my issue is my cotton placement. I'll test it this weekend and let you guys know.

I only want to use the RDA to test juices I make in small batches, because it's cheaper that way. I can reuse the coils, and all I need to replace is the cotton. So, as long as I can get it to vape at 70-80W without burning, I'll be fine with it.

 

[muzichead]

It might have something to do with either the build you are putting in the RDA or the PG/VG/nic ratio you are vaping that could cause you problems also... As I mentioned before, you will get a completely different vape from and RDA to an RTA. They just don't vape the same. The RTA is a much more restricted vape as opposed to a more wide open vape of the RDA.

 

[digitalepiphany]

wicks should just touch the deck, the juice well should not be stuffed and there should be space under the coil

^^^This is what I wasn't doing. I was shoving all the excess cotton below the coil, and on the deck. I'm going to fix that and see how it goes. Of course, it could be more than one thing that I'm doing wrong.

 

[sonicbomb]

Of course, it could be more than one thing that I'm doing wrong.

Quite possibly, but keep trying and keep asking questions and you'll get there.
Bear in mind that higher wattage does not automatically equate to bigger clouds, and bigger clouds doesn't necessarily equate to vape nirvana. There are different vapes for different situations and moods.

 

[digitalepiphany]

Sonicbomb hit the nail on the head. It was an airflow issue.

I removed the old cotton, cleaned everything up, and reinserted my coil. Then, I added new cotton. I made sure to cut each end so that they were both just touching the well. I also changed the position of the coil from horizontal to something closer to 45 degrees. I added my juice, and started vaping at 40W. I slowly worked it up to 70W, and it's still going strong. I'm sure I'll try it out at a higher wattage one of these days, but this at least gets me to the point where I can test the juices I'm making (just tested my first one. Needs some work).

Also, I tested for hotspots on the terminals, and there were none. I'll be on the lookout for that in the future, though.

Thank you, everyone, for your help. I may have been vaping for 7 years, but this is my first foray into VV, RTA, and RDA, so I'm sure I'll be back with other questions/problems.

 

[bwh79]

Again, like I said before, I don't want to vape this thing at 200W. I pointed out earlier that if it should be capable of 196W, then why was it burning at 70W (which is the wattage I'm aiming for).

Whether the power source can dish out 200w or not, and whether the atomizer you've built can take 200w have absolutely nothing to do with each other. That's essentially like asking "well my car says it can go up to 200mph (196 on these tires), so how come I get pulled over every time I take it up past 70?" The problem is not your car, and it's not your tires. If you want to drive 70mph without getting pulled over, take it to the Autobahn. Likewise, if you want to vape 70w without burning, the problem is not your mod, or your atomizer. Put a different build in it.