Fuel for stunt

I was clearing out my garage this weekend (to make room to build a Wing Jig) and I realised that I have about 8 gallons of glow fuel all of which is 20% castor and 5% nitro. a remainder of my RC flying before I was seduced back to the true (circular)path. Now the questions are:-

Am I taking a risk running my spanking new Brodak 40 on this fuel?
I did purchase a gallon of 50/50 castor/synthto run my Stalker 35 on this summer. I was using it for the first time and finding it a little challanging to start on the 100% castor(it was hitting my credibility at the club<G>)but it didn't seem to run any better on the 50/50 nor start better.

What benefits should I see from a mix of castor and synth oil?

I would expect that my Ringed Enya 45 will be fine and I hope that the Fox 40 and the Fox 35 will be fine. What about my Stalker 35?

If I need more power I can add some Nitro but messing with the oil content can only be done by mixing the existing castor fuel with 100% synth fuel.

I am not intending to compete with this stuff but I do want to do some serious flying this winter with a view to doing a couple of comps next year.

How old is it?

Well it is a bit old - some of it at least 10 years but I have used a gallon of the oldest in my RC aerobatic model and found no difference on the starting (mostly first flicks -I hate starters and don't own one) good throttling and tickover. the fuel hase been stored in a dry environment.

I sounds as though I should add a little (5%) castor to the fuel for the Fox 35.

As for the Fox 35, NO LESS than 25% all castor. 28%-29% is better. Some will and 1-2% of synthetic to help keep it clean, but the Fox needs the castor for cooling.
Bill <><

This summer a visitor to our field commented that he had about 8 gallons of old fuel that he wanted to get out of his garage and asked if we might want it. The following week he showed up with it and told us it was purchased in the mid sixties. Rainman did a solids check on it and found it to have an oil content of more than 30% all Castor. I have used it all summer for my old iron piston engines and mixed with synthetics for the newer engines with no problems.

Boy are you lucky. I had a gallon of K&B 25% fuel. I can't remember when I bought it, but it had to be in the 60's. When I opened it up in 97, it spelled like old fashioned varnish, spar varnish. About as thick too. I burned it in a bucket. Not very big flames, lots of white smoke. No mosquitoes for hundreds of yards.

If it's still clean and can fire; I'd get the castor up to a 28-29% range for your two Foxes and use it. With only 5% nitro use it for break-ins and fun flying. Or send it to me, I’ve got a newer Enya that I’ll be needing a couple dozen gallons to break-in.

I understand glow fuel keeps much better than diesel, which is very suspect. Diesel in a plastic/nylon container is a no-no in the long term. The ether gets through the container. Metal is better, but in the very long term ether can still escape at the stopper.
Glow fuels have bigger molecules and seem not to get through the plastic/nylon walls. I recall reports of winners of speed events at the U.S. Nats using "10 year old K&B Supersonic 1000 fuel"! I still have a can containing a little of this in the shed. The tin has well nigh collapsed on itself, due to atmospheric pressure. It brings back happy memories to me. I must try the fuel some time, - may win our Nats with it?