RDA Harsh/Burnt Taste When Using RDA'a

[CrazyChef]

Okay, so I'm starting to get a little more experience building coils. Nowhere near good, but acceptable. Problem is, EVERY build I make has a harsh/ burnt taste to it in any rda I use! Why??? I'm using Lightning Vapes kanthal and Koh Gen Do cotton. I have a Tobeco Turbo V1 rda on the way from VaporDNA and am hoping to get this right. Any suggestions?

Also, with only one exception, all of my subtank mini RBA builds are just fine. Only the RDA builds suck.

Here are pics of my RDA's and some build pics:

Yeah, this one sucks. It was my first attempt:

Gettin' better:

Threw this one together kinda quick:

Better looking, but still harsh/burnt flavor. My 50W iStick takes about 2 seconds to get it going:

 

[Jake287]

When you space your coil wraps, if they aren't even you get hot spots, that could be the problem, try wrapping your coils so the wraps are touching (not overlapping). Make sure your coil wraps are all the same diameter as well, for even heat.

 

[CrazyChef]

Yes, they're even now. My latest coils are much better, I just don't have any pics of them. I have a coil wrapping jig, but sometimes I have better luck just using a 1/8" drill bit.

 

[Jake287]

Yes, they're even now. My latest coils are much better, I just don't have any pics of them. I have a coil wrapping jig, but sometimes I have better luck just using a 1/8" drill bit.

Good, if you're still getting a harsh taste then your wattage may be too high.

 

[CrazyChef]

Okay, I just did a build to show my process. 22g Kanthal at 0.3Ω, 35 watts on my iStick 50W using a Patriot RDA Clone (I didn't know it was a clone when I bought it). Still harsh, with little vapor. Tried it at 25 watts - hardly any vapor, but a little less harsh. Using a 70V/30P DIY juice that tastes great in my Kanger Subtank Mini.

Coil

Clipped coil

Initial burn-in


After burn-in

Cotton

Cotton Folded (Kinda messy, but even distribution)

Juiced

Looks fine


There should be plenty of vapor when I vape this, but there isn't for some reason.

 

[CrazyChef]

Maybe I just have crap RDA's?

 

[KennedyKills]

Generally, I don't think you want to be building the same coils on an RDA like that as you do on your subtank RTA deck. If you want to run single coil, you may want to try a smaller gauge wire and building a little bit higher, while vaping at a lower wattage.

You can also try running a dual coil. Watch a couple of coil building videos on youtube - make sure to pre-heat your coils and press them together/strum them with a pliers(if you are using regular pliers do NOT fire and press the coils simultaneously, you will cause a short) to make sure they are heating evenly.

Another thing may be you are using too much cotton. On my personal go to build which is a 26g 6 wrap on a 2.4mm bit - I always cut the ends right against the edge of the RDA base, that way your cotton ends are just barely touching the bottom for quick absorption right up to the coil. If you have a lot of extra cotton it may not be reaching the coil fast enough to produce good vapor, or if the cotton is touching the bottom of the coil you may be burning some of that cotton while firing. There is a lot of different opinions around the amount of cotton to use out there but that is my own personal preference and I have never had an issue with burnt taste.

 

[CrazyChef]

This is the first build that I've used 22g - I was using 26g and 30g before. I've also done a parallel build using 26g. Same results always.

 

[KennedyKills]

This is the first build that I've used 22g - I was using 26g and 30g before. I've also done a parallel build using 26g. Same results always.

a parallel single coil? If so it sounds like your problem is that your coils would end up heating too fast, so even if you've dripped enough the coil would be burning the juice faster than it can reach it. What mod are you building on? If you have the capability of around 40-50 watts, try doing a dual coil build around .35 to .4 ohms with 26g wire. Use the steam engine coil building calculator otherwise if you have a 2.4mm bit just do 6 wraps of 26, build 2 of those and depending on your leads you will end up between that .35-.40 range. Cut the cottons close to the deck so that they just sit right on the bottom of the deck and try vaping that once. It may not be your ideal vape but if you can at least build that without getting a burnt taste you may be able to use the information to get to where you want to be without the burning. Like I said it's my go-to build for decent clouds and good flavor. Comes out looking like below.

Another thing may be to make sure you aren't using too thick of pieces of cotton either, for the size of bit you are using. Once you have it through the coil be sure to pull it lightly from side to side, if it doesn't move at all it is too tight and could also be causing some of your issue.

 

[CrazyChef]

a parallel single coil?

Yes. I'l try your "Go To" build later on today (got stuff to do for the next few hours).
Thanks!

 

[CrazyChef]

Oh, I'm using an Eleaf iStick 50W

 

[Kprthevapr]

Looks like you have too much cotton wicked in coils. If it's too tight it you'll get a burned taste.

 

[Kprthevapr]

The rda on the right is an IGO single coil rda that should be built at around .5 or higher, the air hole looks like it's been drilled, but there's not enough air flow to build it too low. Same for the one in the middle, it's too small to sub ohm on.
The patriot rda is a good one, make sure the screws are always tight, they have a tendency to back out of the posts.
Hope this helps

 

[CrazyChef]

Immensely - thank you!

 

[CrazyChef]

the air hole looks like it's been drilled

They've all been drilled - the IGO was a PITA!

 

[CrazyChef]

 

[gpjoe]

I agree that it may be too much cotton. Also, it looks like you have wrapped the cotton under the coil. I try to keep the cotton to the sides which allows for maximum airflow above and below the coil.

 

[CrazyChef]

Well, as the great George Takei would say, "Oh Myyy..."!
@KennedyKills Your "Go To" dual coil setup is spot on! Came out right where you said it would @ 0.37Ω.
I left plenty of room for airflow and lightened up on the cotton. Decent vapor (not huge billowing clouds, but a lot better than before), and the harshness/burnt flavor is GONE.

Thanks so much!

Starting point

Heated, straightened (mostly) and wicked

Juiced and (almost) ready to go. Decided to give it a little more undersided airflow as per @gpjoe after this photo

Fired it up


Got some vapor


Got some vapor!


THANKS SO MUCH!

 

[Vyrgg]

Glad you got it sorted =] If the cotton is too tight it doesn't soak liquid as fast so it burns through the liquid and doesn't replenish as fast, finding the right sie of wisking takes time but it's something that'll be second nature soon =]
You still look like you have a little spacing in your wraps, it's worth investing in some ceramic tweezers to push them together when firing them as they're very malleable when hot.

Hope this is a help

 

[KennedyKills]

Awesome, glad it worked out for you! Its definitely not a cloud chasing build but you'll get tons more vapor than any tank with a pretty good flavor. My sweet spot for the build is about 4.25 volts. It'll get a little more dense and a little warmer but still the same flavor.

As you build more and more you'll figure out all the little tricks and find a build suited to your vaping style. Happy trails my friend!