failed evaporation test on newport lighter fluid

[PedroSanchez]

my newport lighter fluid arrived today so i got straight in to the evap test.
i cleaned the bottom of my glass pan with washing up liquid and water then let it dry and wiped away water marks with tissue. then i dropped a couple of drops on there and left in front of a fan about 1-2 foot away for about 2 hours.
when i checked there was a definite residue there. i couldnt see it in some light, but when i shine a torch from the other side it is clearly there.

the data sheet for the lighter fluid says it is "VMP C naphtha" and i have heard about others using the same solvent with success, but yet it left a residue. could i be doing something else in the process to cause the residue?

here is the data sheet:
http://modelshop.co.uk/Content/DynamicMedia/cms-uploaded/files/FH30004 Newport Lighter Fluid.pdf

thanks for the help

 

[PedroSanchez]

i had some clipper lighter fluid lying around so i tested that too. it was slightly cleaner, leaving only a ring, but it was still not clean.
any other suggestions for solvent in UK?

thanks

 

[Kyngwhatt]

is shellite fuel available in your country, I've also heard unscented charcoal lighting fluid works I've never tried it but it makes sense that it would be clean.

I'd be interested in hearing about the current state of the united kingdom.

 

[Blazon]

surprised Newport failed the test as the gas version is well known for BHO,in cyb's hybrid tek he is using Swan,I have done the evap on a pan and foil looked clean,could there be a difference between evap test done quick or slow?

Have you tried Bull Brand?

 

[downwardsfromzero]

I've written elsewhere on how washing up liquid may leave a residue which is made visible by naphtha. Detergent residue should be removed with an acid (HCl) rinse, or you could try using acetone for the rinse if it hasn't been stored in plastic.

All the more reliable ways of determining solvent residue seem to involve a certain commitment to technical capability one way or another. That being said as a preamble, it's possible to build a microgram balance, then weigh a small piece of aluminium foil before and after having a known amount of the solvent sample evaporated on it.

Come to think of it, perhaps it would be worth simply evaporating the naphtha on a piece of brand new, shiny alu foil. But what manufacturing residue might it be coated with already?

How about giving the glass pan a clean with the naphtha (wipe with a paper tissue) and then trying the evap test again? That way, if the glass was dirty it should now be clean(er) so any residue that turns up is more likely to be from the naphtha.

 

[PedroSanchez]

i should have updated this post with the latest info. i forgot it existed, sorry guys.

another solvent was suggested to me that was much cheaper so i bought enough of it that i was willing to do a full scale test. i suspected there was residue left from the cleaning process i used, so i thought if i used more naphtha for the test then this should help move some of that residue elsewhere, rather than just settling back where it started.
it seemed to help, so i did another test with different sized pools of naphtha and the bigger pools definitely left less residue, with the biggest leaving nothing at all. i then repeated the tests with the original solvents and got similar results with the others.

a while after i discussed it with downwardsfromzero in another thread where he confirmed my suspicions. as he said above, these cleaning agents can leave their own residue. i was using washing up liquid, which i imagine is far from clean.

i plan to get some microscope slides for this purpose in the future. they will certainly be cleaner than my attempts. in the long run i plan to acquire all the necessary knowledge and equipment to do this properly, but for now they should be okay.


for the record, the clipper fluid was in every shop i tried when i was looking for newport. it seems they have dominated the market, which was very disappointing a the time. i traveled all across my city for hours looking for a shop that sold newport, or even something that was not clipper. after my improved tests it seems that clipper was the cleanest of all the corner shop lighter fluid options (and the cheapest), so i was hunting for what was already in my cupboard at home
although clipper fluid is the cheapest out of those it is still far more expensive than other options that are not branded as lighter fluid, so i am glad i went through that now as the solvent i landed with is much better bang for my buck