Hi TJK,
Quick Sport's method is the best if you've got the equipment and the math skills.
Historically most home brewers mix by volume though. In the days before cheap accurate electronic scales there was no choice really.
I'd have to disagree with Quick on the large manufacturers though. Mixing by weight is a better industrial process, you don't have to worry about the temperature of your components or of the final product. You get a consistent product from one day to the next.
Quick is right though, you have to adjust the percentages of each component according to its specific gravity to end up with the equivalent of the by volume mix.
psgugrad,
Good on you for trying the DIY fuel.
I've used home brew fuel for the last 30 years on both glow and more recently Diesel.
I would have thought your 12% oil would be fine for .46 and up engines as long as you're a bit careful with the tuning, smaller engines might be happier on a bit more oil though.
My brew is 18% synthetic which I use on 2 and 4 stroke engines. I've got engines with over 300 hours with no undue wear or corrosion.
Cheers,
Dave H
Last edited by gerryndennis; 08-25-2015 at 02:18 AM.