JohnVH

My Feedback: (38)

you missed the point, other than the cheap fuel, not needing a bunch of extra crap to make them run (ignitors, starters, glow plugs, etc)

psgugrad

My Feedback: (2)

http://www.bulkapothecary.com/raw-in...ls/castor-oil/

16.67/Gallon plus $10 shipping from OH to IL. If you're in TX you'll likely pay a tad more for shipping, but it's still a great price

1QwkSport2.5r

I would want to know if that's from the first pressing or from subsequent pressings. First pressing doesn't have the gum substances in it the subsequent pressing have. "De-gummed" castor oil is from the first pressing and is the oil you want to be using in model engines.

Dick T.

My Feedback: (243)

Auto wax works good. But, I use a product call "Gel-Gloss," available in the shower/tub cleaning section at most hardware stores. It is a crème formulated for fiberglass, plexi, plastic cleaner and polish. Makes the shine on Monokote look inches deep. The polished finish is so slick most everything wipes off easily with a moistened towel.

Good stuff for polishing canopies and painted parts too.

gerryndennis

G'day 1QwkSport2.5r,

I'm not quite following your post #18. Are you saying that a manufacturer who sells say '10% nitro' fuel but mixes by weight uses 10% of the weight being nitro? I don't know why a manufacturer would do that. If that is what you are saying, do you have any examples?

We all understand and expect that a fuel advertised as say 10% nitro should have 10% of the volume of the fuel being nitro.

If a manufacturer chooses to mix by the weight method then he isn't going to make 10% of the weight of the fuel nitro, he's going to work out how much that 10% volume weighs and use that figure. Isn't that exactly what you said you do in post #15?

To repeat myself, if the manufacturer is mixing say 20% oil, 10% nitro, 70% methanol fuel by the weight method he won't be using the figures 20, 10, and 70. He'll be using the specific gravity of each component to determine whatever weights are required. If he wants to short change the modeller on oil or nitro he'll just do that by reducing the weight of those components in the mix, but as you point out, it's easy enough for the modeller to check so why would they try and rip us off?

If you mix by volume on a hot day your product will be different than if you mix on a cold day, that's the advantage of mixing by weight. The product is consistent from day to day.

You can describe your fuel either by weight or by volume, and you can mix it either by weight or by volume. It's the exact same fuel (if you do it right).

There are good reasons to mix by the weight method. And good reasons to describe it by the volume (that's what we modellers understand).

I have no proof that this the case but it is logical.

Please accept my apology if I've misunderstood your posts.

How're you getting on with your Diesels?

Dave H

1QwkSport2.5r

It is assumed that businesses are out to make money. Not saying they all do or will do it, but I know some RC car fuel makers mixed their fuel by weight and that isn't volume converted to weight. 30% nitro 8% oil racing fuel was 30% nitro by weight and 8% oil by weight. Which means they essentially shorted the user on oil and nitro. I just assume since they're in the business to make money that some companies are cutting corners and using a straight weight figure and not doing the volume to weight conversions. If you mix by volume only, it's by far the easiest because it's X ounces of part A, X ounces of part B, and so on. With today's technology, there are machines that can accurately measure volume as easily as by weight. For the modeler, there's extra math involved to work by weight but I suppose a computerized blending system could do the trick if every modeler had one. I'd love to take a tour of a fuel blending factory and see how they really do it. Some of that stuff is hush hush. It's good to know Wildcat states they mix by volume and what goes into the fuel they make. Not many companies do that.

The only reason I mix my own fuel is because it saves me a lot of money. $10-12/gal average versus $28-34/gal at the store. Volume converted to weight works well for me, but I don't have a hydrometer so I don't bother doing the air temp/density conversions.

In short - some fuel is what they say it is, others not so much. It's easy to verify oil content, but not easy to confirm methanol and nitro content.

Been busy getting ready for a family vacation. Got the ether, need some kerosene & ignition improver, and some time to set the engine back up, convert a fuel tank, and let her make some noise. Before fall it should run again. (The Fox .50 diesel)

downunder

Historically, meaning from the late '40's, modellers always mixed by volume because it's simple and trial and error determined what a safe blend was even if that "safe" blend varied a little over time so it's accepted that any % markings on bulk manufacturer's fuel labels mean by volume. Yep, some have been known to cheat. However there's nothing wrong if a reputable company mixes by weight so long as the final result gives a commonly accepted volume at a standard temperature which I believe in America is 59F.

Once you know the SG (density) of the 2 or 3 ingredients in our fuels it's quite simple to make up a spreadsheet to convert whatever volume you want to a weight and do the mixing on digital scales by zeroing the scale before adding the next ingredient. Essentially this means that, regardless of temperature when mixing (winter or summer), you'll end up with an exact same fuel blend all year round. This actually suits the engine because we don't tune the needle for a volume of fuel flow but a mass of fuel flow. But that's being pedantic .

gerryndennis

Hope you have a great vacation Quick.

Jet A fuel is really good for the kerosine component if you can get it. Amsoil is a great ignition improver.

Mixing your own Diesel fuel is almost back on topic isn't it?

Cheers,

Dave H

TroyTrojan

My Feedback: (17)

Great information on blending your own glow fuel. I've enjoyed reading the thread. Maybe I missed it, but I did not see anything regarding the use of an anti-foaming agent. Do any of you use or need an anti-foaming additive? And if you do, what do you use and how much?

OliverJacob

My Feedback: (12)

I'd be very interested in mixing my own fuel, just can not find any local sources and shipping makes it too expensive.
I am very happy with my castor/synthetic blend with 15% nitro - I'd want the same mixture, great universal fuel for my two and four stroke and helicopter engines.
A gallon is about $24 / gallon plus a 100 mile round trip, plus more parts and more planes I always wind up buying....

Gasoline works great on large models, but for the small and fast stuff they are too heavy.
Electric motors do not make the right noise, maybe some edf jets, but most planes sound more like a hair dryer (and I have some of those too)

1QwkSport2.5r

I have a fuel station that sells kerosene for about $4 a gallon. Jet A will be harder to get I think.

Vacation on should be fun. Taking my 2yr old fishing for the first time. Should be a good time.

1QwkSport2.5r

If your fuel tank is padded/isolated well enough, you shouldn't need any defoaming additives. The engines that vibrate more (high performance engines like Jett and Nelson) should use a bubble/free tanks like BubbleJett and Tettra. Otherwise a few drops of Armorall original work well but may cause your glow plugs to crap out on you a little faster. I used to use Armorall in my RC car fuel but I quit doing it because I isolated the tanks better.

sarpet

Remember that nitro is virtually impossible to get in (most) countries outside the USA so it's not necessary...we're practically the only ones using it.

Do you live in bottle?
Where did that was invented?
In europe we can buy nitrofuel from every country or order it online.
Sorry my bad english and google translater.

OliverJacob

My Feedback: (12)

särpet - I agree. You can get nitro pretty much anywhere, it is just more expensive.
I remember in Germany we had normally no more then 5% nitro in the fuel. Except some racers or rc cars, they got up to 40%.
Some ran without nitro or add just 1%.
It was always available, just pricey.

And people here live under a rock, not in a bottle .
I hear assumptions and opinions on a daily basis. Somebody told me Germany didn't have paved roads. So the Autobahn would be some sort of dirt road in their mind Just don't take everything you see here too serious.

edh13

My Feedback: (9)

Huh? The only difference being - Gas guys have to fly with their ignition source and batteries, Nitro guys can leave that stuff on the ground.

Nitro guys always tout the weight savings with Nitro engines but we usually forget to mention we have to carry around twice the fuel weight.

Starters = Wash. I can start both with a flip. Or lots of flips, or just use a starter.
Eric

psgugrad

My Feedback: (2)

I don't use any anti-foaming agents...and thus far have had no issues with lean runs. As far as the mix is concerned, I use the following highly scientific method: 15.5 oz castor oil in a gallon jug then add methanol up to the gallon mark I have on the jug. Works out to about 12%

psgugrad

My Feedback: (2)

I've heard from several people on this site from Europe asserting that modelers in Europe hardly ever use nitro and that it is extremely difficult to find and quite expensive. If you can get your hands on nitro that's great, but I wouldn't brag about it too much...IMO nitro's main function is to cover up tuning mistakes.

Kim Couturier

My Feedback: (120)

I am interested in this....I fly glow...have only tried gas once...didn't like the smell. My first question is this....I've found, in the past that my four strokes ( mostly OS) don't run well with less than 15% nitro. How does your mix work with four strokes? Also, where would you get methanol in northern Mi.? Where to get the castor oil? If castor is so good, why are the fuel companies going to synthetic?

1QwkSport2.5r

Nitromethane's main function is not to cover up tuning mistakes. It does make the tuning window wider so it's easier to find that "sweet spot", but it's primary function is to add power. It carries a ton of oxygen with it which means you can burn a lot more fuel which results in more power. An engine running 15% nitro will make 600-1000rpm more than an engine running on zero nitro fuel.

One can maximize an engines efficiency (power production) by adjusting the combustion chamber shape, compression ratio, and the glow plug beat range to get the most power from the fuel but this requires extra skill, special tools, and a lot of time in some cases. Anyone can use FAI fuel, but an engine running with nitro in the fuel will almost always make more power and run cooler, and in a lot of cases be more reliable.

1QwkSport2.5r

Because some of the synthetic oil burns which helps make a little power. Most often, castor oil doesn't burn but just gets blown out the exhaust. More oil being burned means less getting sprayed all over the plane. Synthetic oils tend to keep the inside and outside of the engine cleaner too, however it doesn't handle heat as well and in a lean run situation, the oil "unzips" and breaks down (burns) and doesn't lubricate anymore. Castor just turns to a varnish when it's overheated and continues to lubricate.

OliverJacob

My Feedback: (12)

Main function is to gain power, secondary -it makes tuning easier. And Nitromethane is readily available in Europe. It's expensive, you can purchase as much as you want as long as you can pay for it. Hazmat shipping isn't cheap either.

Very often you find someone in a larger club who mixes the fuel for the fellow members.

drac1

My Feedback: (4)

No problems getting nitro in Australia. I pay $11 AUD per litre.

drac1

My Feedback: (4)

Biggest load of rubbish I've heard in a long time. If you can't tune an engine, adding nitro won't help. If you can't tune an engine, go electric

Nitro = power.

sarpet

https://www.karkkainen.com/verkkokau...aineeseen#spca
And every hobbyshop sell nitrofuel.
http://www.hobbypeople.com/shop/inde...cPath=34_5_112
http://www.westonuk.co.uk/westonuk2_006.htm
https://www.lindinger.at/en/airplane...erplants/fuel/

Sport_Pilot

A good thing about glow is there are no ignition modules, no worry about a spark to ignite leaking fuel. Not to mention more power for the same sized engine.