Another heroic failure!

[Julian]

Well, I tried ... I remember from many years ago during visits to oil tankers, seeing a paste smeared on the end of dip tapes used for gauging oil tanks.  The paste changed colour indicating the depth of water at the bottom of the tank.

This is the stuff ...




Noticing how methanol goes milky when mixed with water, I tried mixing methanol with wet and dry oil samples and ... both went cloudy, shame.

I wonder if there's any other type of liquid that would behave this way in both oil and bio?  It would make for a quick and easy test as to quality. 

[dgs]

Not quite sure what you are getting at here Julian.

There is a simple and crude test for excess water in biodiesel which is to mix 50/50 with a petrochemical like petrol, diesel or probably white spirit. As the resultant mix cannot absorb as much water if the water in the biodiesel is high like around the 8 to 900ppm range (but still all dissolved so the bio is clear) the resultant mix will be cloudy. Not very scientific but it is an indication if the water was really excessive.

[Julian]

I've not come across that test before, interesting.

All I was thinking was that if a water indicating paste is available (all be it for free water), then is could something behave in a similar way for dissolved, trace amounts?