Dry deposits from e-juices - discussion and photos

[kinabaloo]

E-juices have varying quantities of 'dry deposits' - ingredients that will not vaporize and build up in the atomiser. Some of this will get burned on the coil and harden, which is one of the main routes to atomizer death.

Here are some pictures of dry deposits posted by Peter Knutsell at e-cigtest:



The pictures are not great but gives an indication of how much the residue can vary.

Not surprisingly, the unflavored juice leaves very little residue, as most is due to flavorings, flavorings by and large developed for food, where residue is not an issue.

More specifically, the dry residues are not the flavor chemical itself, because that is vaped, but other things that were dissolved during the extraction process, such as sugars, starches, colors, gums and resins.

Artificial flavors would be expected to leave very little dry residue, and probably none, because they are essentially one chemical; not all taste good though and a few might not be healthful (e.g. vanillin). Natural extracts will probably vary a lot.

In one or two cases it looks like the dry residue is not actually dry - that there might be some oil in the juice too, although it could be VG because that is very very slow to evaporate at room temperature.

[Skad]

Can someone translate the captions on those for us?

[MonkeyMonk]

kinabaloo, This is facinating!!! Thank you so much for posting!

[Keef]

I dont speak Dutch so dont hang me.

Ruyan
After it evaporated there is a thin layer,
With rinsing it pretty much all disappeared,
Residue left removed with a damp finger.

Sedansa
After it evaporate a thick dark layer.
The largest part disappeared with streaming water,
The remainder needed a dishes brush to remove it.

Parties Smoker
After it evaporated,
With rinsing it disappeared to a thin layer,
Nearly all gone.
Remainder removable with a damp finger.

JC
After it evaporated .
Needs a robust attack, (the particles) must be removed with water and sturdy dishes brush.

Janty
After it evaporated there is a thin layer,
largely disappeared with through rinse,
remainder needs a dishes brush.

[katink]

Not bad at all Keef!


Tasteless from E-Cig China
After being evaporated: a thin layer, that went away almost completely by just holding it under the tap; rest of it by going over it with a damp finger.

Bickford apple flavoring
After being evaporated: a very light tarnish that was taken away with one single wipe of a finger

Johnson Creek (If I remember well, this was Hickory; and was probably from those first batches, before JC changed their juice to remedy the clogging that was happening)
After being evaporated: a considerable tarnish, which had to be taken away with water and a sturdy brush



Party Smoker
After being evaporated: a thin layer that vanished almost completely by just rinsing; rest by using a damp finger

Sedansa Tobacco
After being evaporated: a considerable, dark layer. Most went away with rinsing under a tap, rest with using a dish brush

Ruyan (the original)
After being evaporated: a thin layer, almost completely taken away by rinsing, rest by using a damp finger



E-Cig China (doesn't say which flavor; I remember it made quite a difference which flavor as to the outcome for E-Cig flavors: tobacco-tastes were a lot less worse then fruit-/sweet flavors - I think, but not sure, that this was a tobacco-flavor)
After being evaporated: a sticky layer, that could be taken away with a dish-brush

SuperSmoker-liquid
After being evaporated: a hard black layer, that had to be cleaned by scraping and using a sanding sponge

Janty Tobacco
After being evaporated: a thin layer, taken away largely by rinsing, rest by using a dish-brush



(0.5 ml being evaporated (on a teaspoon) above a moderate flame)

[Keef]

Thank you Katink

I did wonder if the JC was before they changed the manufacturing process.

I also am wondering did they just leave the liquid to evaporate ?.
Or was it heated on the spoon and if so by naked flame beneath or oven dried ?.

[katink]

(0.5 ml being evaporated above a moderate flame)

So above a moderate gas-flame.

[Keef]

Duu I did not translate that bit

Thanks again

Well I have Bulldog here by JC so may take a stab at a new test.

Though this latest batch is much lighter more golden in colour, the others I have had were more like irn-bru .

[kinabaloo]

As long as the heating is not done too fast, this approximates to room-temperature evaporation in results but is much faster.

Everything left behind in this way will also be left behind in the atomizer. But atomizer heating conditions are very different and are likely to burn (decompose) these deposits, and there may be some reactions too.

[Keef]

Well I tried the JC Bulldog on the spoon test.

It looked like the first pic Nieuwe E-cig Smaak Tasteless.
Some came off under the tap and the rest came off with a damp finger.
No dish brush required.