Dear Stuart Welcome back. I read your latest article and, as always, found it very interesting and controversial as usual. The comments on methanol and microscopic water droplets I just can't let go without some comment. I'm a research chemist with some practical background on recovering methanol from process solutions on a reasonable scale ( I ran a recovery plant distilling 1000's of litres of methanol per day from water and other solvent contaminants. One thing I learned quite early in the piece is that water and methanol are completely miscible at all concentrations. That is they actually form a discrete amorphous compound. If the NASA man found microscopic droplets then he is following in the footsteps of the "polywater" guys. Both methanol and water molecules snuggle into one another to form a lowest energy fit (notice water and methanol when mixed give out heat as they form this more stable grouping in solvation) and occupy less volume as they fit together. 50 mL of methanol and 50 mL of water = 95 mL of solution. Even with an electron microscope I don't think he is going to find water droplets in pure water and methanol If you add water to 20% castor with 5% Nitro 75% methanol nothing happens until you reach about 3-5% water (this in very dependent on temperature, the lower the temperature the earlier droplets appear) and then the oil starts dropping out of solution and forms fine droplets. It this solution is allowed to stand the oil coalesces and form a gloppy layer (yes sir, scientists can have gloopy layers) Maybe thats what these guys are seeing in their glow fuel. Regarding detonation, this does not make sense either, if reason prevails. Stay with me Stuart, detonation is an uncontrolled explosion, and an uncontrolled explosion is when all those free radicals in the burn just go crazy and move out all over, not just in the flame front. Water is a free radical quencher and should slow down the flame front. In fact methanol when lean can detonate badly, but add water and it becomes controlled. Add too much and the flame front won't even propagate. Remember all those engines that ran methanol with water injection during the Second World War. I remember in the 60's we used to add water to the glow brew for B Team-race to give us a little more range. We noticed the motor ran a little slower and was a little harder to start, but it did give us some more range. We never noticed any detonation. This brew fell out of favor very rapidly when we discovered the consequences of water and not being able to control the daily temperature. On cold days the fuel had a tendency to suddenly precipitate oil. Droplets of oil forming during a race was like having sand in the fuel. It just gummed up the fuel line (or was it glooped) and everything just stopped. But I digress. Methanol is not highly hygroscopic as substances go, so keeping good quality fuel in waded screw cap non porous containers will prevent the ingress of moisture from the atmosphere, glass is good, some plastics are excellent, some are porous. Chose you plastic containers wisely. Putting fuel from a sealed container into a fuel bottle for a days flying should not cause too many problems. Don't leave in in the fuel bottle with fuel in it for longer periods, otherwise water will exchange into the fuel from the air and more importantly methanol will evaporate too (faster than the water). Water in methanol is easy to measure. Silica gel is not the answer. It is not meant to indicate water in solvents but it is sometimes used that way. A simple pocket refractometer will give you an accurate measurement of water content, without any chemistry or electronic analysis required. It doesn't even have a battery. It also give you a number, and that is something us scientists go orgasmic about. Also a simple hotplate, tin and thermometer boiling point test will give an accurate measure (yet another number) for those of us who like to live slightly dangerously. (latent and not too latent pyro's) I can provide both refractive index and boiling point V water content tables for those of us that are interested. No problem. Lastly but most importantly, silica gel ( a form of dehydrated porous silicon dioxide) does dissolve in methanol, ever so slightly but who wants that (sand) as residue in the combustion chamber now. It also contains some very fine solids, which are not nice in anyones fuel. Hey it might be simple, but it could also be expensive. Methanol is relatively cheap. Best to throw it out if water is detected. I think I would stick to redistilation. Engines are too expensive. Kindest regards Lance Smith