Sorry for the delay in replying to this but it's been a busy few weeks!
I don't know whether Black Jack will crack a Poly tank. I use an EGO-T copy that was given to me in February
and is running fine without any replacement parts and with just the occasional wipe inside with a tissue!
This subject was covered in some depth on the UK Vapers forum and I have pasted my reply below.
So long as people keep buying stuff that isn't up to the job required of it nothing will change.
This is an interesting topic and one that prompts the obvious question;
should we stop using any liquid that might have a degrading effect on polycarbonate,
or should we require manufacturers to use materials that are 'fit for purpose'?
Polycarbonate is just one of a number of materials that might need to be avoided,
not just from a consumer standpoint, but to help safeguard the future of ecigs.
When the detractors point out that material 'x' could be dangerous to health, we need
to be able to reply "yes, we already thought of that and do not use it".
Self-regulation is more than a catchphrase, we have to prove we are responsible enough
to establish standards and maintain them, which is realistically achievable.
Some ingredients might have a negative effect on the mechanical integrity of the material
causing it to weaken or even crack, whilst other ingredients might react in other 'invisible' ways.
There has been a lot of research into Food-Grade Polycarbonate, mainly concerned with the possible
thermal degradation in air of polycarbonate and the formation and the release of bisphenol.
Throwing eliquids and atomisers into the mix gives the issue a new dimension, we don't know all of
the reactions taking place, but we do know of some for certain.
A lot of work is being done to ascertain whether vaped eliquids, particularly flavoured ones, produce
any adverse compounds and the results are reassuring so far. So if it seems like the flavoured liquids
do not pose a threat in themselves, but might when they react with other materials, why not change
the other materials to something less potentially volatile if it's available?
I suppose a simple analogy would be that most of choose to vape because we have available a preferable
and less harmful alternative to smoking. We enjoyed smoking and choose to continue enjoying the experience.
Having trawled through lots of links, most of which seemed to be written in Martian, I came to the conclusion
that I would avoid polycarbonate if possible, rather than have to forego certain flavours.
Someone mentioned a cloudy appearance, which is a similar (but milder) effect that Wormwood, a primary ingredient of
Absinthe, has in concentrated form on HDPE (High Density Poly Ethylene), meaning it has to be stored in glass.
I've pasted some text from Bayer Material Science LLC and a link to just one of the many articles on the subject.
Someone said that vapers are the Guinea Pigs of the industry, I like to see us more as Test Pilots.
Cheers
John
General Characteristics of Polycarbonate
Hydrolytic Stability.
Parts molded from polycarbonate absorb only 0.15 to 0.19% water at room temperature and 50% relative humidity.
Dimensional stability and mechanical properties remain virtually unaffected. Even with immersion in water, dimensional
changes measure only about 0.5%. Although frequent, intermittent contact with hot water does not harm polycarbonate,
continuous exposure to humidity or water at high temperatures (>140°F/60°C) is not recommended due to hydrolytic
degradation, which reduces impact strength and tensile properties.
Gas Permeability.
Steam permeability, measured on 100-μm thick film, is 15 g/m2.24 h (0.97 g/100 in2.24 h).
Significant permeability also exists for other gases, such as hydrogen, carbon dioxide, sulfur dioxide, helium,
ethylene oxide, and oxygen.
Chemical Resistance.
Polycarbonate is resistant to mineral acids (even in high concentrations), a large number of organic acids,
many oxidizing and reducing agents, neutral and acidic saline solutions, some greases and oils, saturated
aliphatic and cycloaliphatic hydrocarbons, and most alcohols.
It is important to note that polycarbonate is degraded by alkaline solutions, ammonia gas and its solutions, and amines.
Polycarbonate dissolves in a number of organic solvents, such as halogenated hydrocarbons and some aromatic hydrocarbons.
Other organic compounds cause polycarbonate to swell or stress-crack, e.g., acetone and methyl ethyl ketone.
Since chemical resistance to various media is dependent on variables, such as concentration, time, temperature, part design,
and residual stresses, the above information should serve only as a guideline. It is imperative that production parts be evaluated
under actual application conditions prior to commercial use.
Regulatory Compliance Information
Some of the end uses of the products described in this bulletin must comply with applicable regulations, such as FDA, NSF, USDA, and CPSC.
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