Posted on August 18, 2014
I have looked at the problem with gunked up coils for a while, like a lot of you here.
The reasons why the coils gunk up are because of the tobacco micro particles, but mainly the sugars. I don't know if we want to remove all the sugar and "flavor" particles.
Other major contributing factors are the heat of the coils, coil wire size, coil inside diameter and the lack of proper juice flow to the coils.
Looking at the coils and juice flow issues.
Smaller diameter coils...lets say 1/16", in general heat up quicker and get hotter in short burst then larger diameter coils. All things being equal.
Also smaller diameter coils burn juice faster in short burst.
Ok. All things remaining equal.
1/16" diameter coil at 28 gauge, 5 wraps using cotton as the wick. Lets say at the coil this setup can hold 1ml of juice. (of course 1ml is too much juice, but easier to work with in this example)
If a short burst boils off 1ml of juice in lets say 2 seconds, then in a 6 second burst the wick material would have to replace the juice at the coil 2 times with in the last 4 seconds. In other words the wick would have to pull 1ml of juice every 2 seconds to maintain the vapor.
Now the wick would be hot at the coil, and would boil the first 1ml of juice within 2 seconds burst. Once the first 1ml is boiled off, the next 1ml would be trying to replace it. This is where one of the problem is.
As the next 1ml is entering the coil....it is being boiled at the outside edges of the coil....because the coil is even hotter after the first 2 seconds. One because there is no juice left in the coil to keep it cool, and second the coil gets hot the longer it burns. Also the coil is hotter in the center, then on the outside edges.
The now concentrated juice left in the center of the coil, and the wicking material starts to burn. This causes the coil to gunk up. As the coil gunks up....the coil "crusts" over. This in turn exacerbates the issue. The crusting cause the coil to no longer hold 1ml of juice...which over a relatively short period of time....causes wicking issues and the dreaded burnt taste.
Ok. All things remaining equal.
1/8" diameter coil at 28 gauge, 5 wraps using cotton as the wick. Lets say at the coil this setup can hold 1ml of juice. (of course 1ml is too much juice, but easier to work with in this example)
In theory....a 1/8" diameter would hold 2mls of juice at the coil, and heat up slower. If the coil were to heat up at the same speed as a 1/6" diameter coil then a 1/8" diameter coil would boil 1ml every 2 seconds.
Without going through a detailed breakdown like above for the 1/16" diameter coil. In theory....a 1/8" diameter coil would go a long way in helping to resolve the issue with gunked up coils.
Now saying all that.
I have been using 1/8" and 3/32" diameter coils at 26 gauge on a mechanical mod for over a year. Not the same coil...I do have to change them out every week or so.
For all intents and purposes....gunked up coils are a thing of the past for me.
I don't get the same vapor production I use to get using a smaller diameter coil...but I am not a cloud chaser....I am a flavor chaser.
Some key point I have learned over the year with a 1/8" coil.
1. Don't twist the cotton in the coil. If you twist it, untwist it when it is in the coil.
2. Don't over pack the coil...and don't under pack the coil.
3. Don't pile your cotton under the coil.
4. Raise the coil up a bit higher, make sure it has air around it to breath.
5. Bet RDA I have used is the Magma....the cotton is controlled better in this RDA.
6. Don't run dry. Always keep the dripper properly hydrated.
7. Fresh batteries help a lot.
Hope this helps some out there.