High acid fuel

[jeffie8696]

There has been report of high acid content nitro sneaking in from China causing bearing issues . If you have access to some litmus paper you can do a simple test to determine if your jug has too much acid.
According to Fred Lewis of Morgans fuels they ship fuels that are in the 4 to 5 range meaning only slightly acidic.
It would be interesting to see what your findings are.

[RCModelReviews]

Yes, I encountered a batch of low-pH (hi-acid) nitro once.

You could tell by the smell and the color that it wasn't right.

Instead of being as clear as water and relatively odorless, it was a straw-brown color and had a very sharp smell to it.

The pH was low (about 5.5 from memory) and I tried some out by running a couple of tanks through an old motor (which had just received new bearings so I knew it was 'clean' inside). When I pulled the backplate a few days later it was totally rusted.

This is one of the reasons I prefer to blend my own fuel -- it allows me to be 100% confident that the stuff I'm putting into my engines, won't destroy them.

One of the worries is that as nitro prices continue to climb, some fuel blenders will inevitably opt to use lower-grades which are more likely to have a low-pH -- in the knowledge that it's easier for them to blame "a failure to use proper after-run oil" than the fuel if people start bitching about bad bearings and rust.

Those of us who can remember back to the days when glow-fuel was 20% castor oil and 80% methanol will fondly recall that rust was never a problem with our engines and nobody ever (ever!) had to change engine bearings.