Would nylon, Polyurethane, Polyethylene or Polyvinyl Chloride work with nitro? Or just stick with silicone?

I assume you are talking about fuel lines. Why would you not use silicone?

For fuel lines, the silicones seem to work fine and are readily available

Just curious

You can use neoprine rubber or silicon rubber, and latex rubber as well. I never tried the other stuff with glow fuel.
But it may work OK though. You can put a piece of the stuff into a small vial of glow fuel and wait a few hours to see what happens. Gasoline tends to dissolve most all these things, so if glow fuel doesn't dissolve it, it is probably good.
before silicon tubing became available, we used to use neoprine or the clear plastic flexible tubing like the stuff that COX engines used.
But the clear plastic tubing tended to get hard over time and wouldn't hold a seal well.

Latex rubber slowly degrades over time. It is floppy, kinks and squishes easily and costs more than silicone, and is not usually sitting on the LHS shelf in rolls for $1 - $1.50/foot. It's good for pressure bladders and shut off timers and needs occasional replacement but no matter for those apps. It is also good for bungees, histarts, and tourniquets.

Polyu does indeed embrittle.

Polyethylene is very stable and chemically resistant. Do you have some flexible PE tubing that would work well on a fuel system? If so then use it.

Silicone has many desirable properties for glow fuel, and nothing else I've ever used works better and costs the same or less so why bother IMHO.

MJD

Silicon is silica based (glass).

Silicone is more rubbery feeling. I don't know its chemical base, but it isn't the same as Silicon, without the final "e".


Ed Cregger

So, essentially, fuel lines are consumables when flying glow fueled models. Like glow plugs, propellers and fuel, they are consumed over time and they need periodic replacement. There is no such thing as life time lasting fuel line. <G>


Ed Cregger

Nope.

Silicon is a hard, brittle grey metallic element. Silica, silicones, etc are all based on silicon.

React it with oxygen - i.e. burn it - and you get silicon dioxide, also known as silica, which is very common on beaches, sandpaper, adhesives, flooring materials, and even in some foodstuffs in the form of fumed silica - Cabosil if you will - to help them flow freely. It is known in the Republic of California to cause cancer.. when breathed excessively in dust form.

Form polymers from siloxane groups - SiO, silicon and oxygen - and organic compounds and you get polysiloxanes, also known by their colloquial name, silicone rubber or just "silicone".

Natural rubber is a compound made primarily of carbon, hydrogen, and oxygen. It does not behave like any of those three elements any more than salt in your mouth behaves like a mixture of sodium metal and chlorine gas. Thank goodness.

Silicone polymers have specific properties that make it an ideal choice for glow fuel tubing - high temperature resistance, decent mechanical properties (not great but decent enough), low temperature flexibilty in particular, and is chemically very resistant to methanol, nitromethane, and model engine lubricants. Therefore, it is the best choice of the commonly available tubing materials.

The other materials may work to a fashion, but they give up something in exchange for whatever compelling reason you choose to use them over silicone tubing. For example, latex tubing is soft and squishy and makes good pinch-off line, or pressure bladders, or high starts, bungee launchers and tourniquets. But, it degrades much more quickly in the presence of glow fuel than silicones do, and therefore if you use it you use it for a specific reason - to lever a property of the latex that silicone does not possess - and then you have to put up with the caveats in the process, like replacing it more frequently.

Same deal as latex balloon tanks - light, cheap, convenient, work great; but they degrade and require periodic replacement. Due to the lack of perfect materials, you usually pay for one property with another.

In the end it boils down to this - unless you have a specific reason to use other than silicone tubing for glow engines, don't bother. Cost is not a valid reason, it's cheap.

MJD

Well, my point was that silicon and silicone are two completely different things. I'm not a chemist, but seeing something spelled wrong all of the time is irritating - even to someone like me.

Now, if we can just get the southerners here in the USA to realize that the words "our" and "are" are not the same. Today I saw someone using the word "or" to replace both of the other two. Argh!

We modelers are already thought of as being immature dolts by most of society. We do not need to prove their point with incorrect spelling.


Ed Cregger

The misuse of then, than, ran, and run irks me.

Sillicone

from wikpedia

Silicones are largely inert, man-made compounds with a wide variety of forms and uses. Typically heat-resistant, nonstick, and rubber-like, they are commonly used in cookware, medical applications, sealants, adhesives, lubricants, insulation, and breast implants.

From me

Silicon is an a basic element, SI. . It is the basics of the electronics industry. Elemental silicon is grown in long crystals that are sliced into waffers that IC chips are printed and etched from.It is a grey metalic material.Quite brittle. It has been cut and polished into gems, and decrotive items like spheres. Most gem cutters hate it beacause of the mess left from cutting and polishing. . Silicon dioxide SIO2, quartz, the most comon mineral on earth. From it come a range of products, from Amethest and Citrine gem stones. to the basefor window glass. Itis also the the basic frequencykeeper for our RC equipment, the Crystals whihchare cut from syntheticQuartz today, but during WWII, it was a stratigic mineral and was horded by the governmet as synthetic quartz had not yet been developed. When the govennment released it stock pile of quartz,some of the finest mineral specimens ever know were put on the market, asthe hord of quratz for"crystals" forradio and radarequipment, had to be a pure as possible in order to give accurate frequency control. Synthetic Quartz made the natural quartz obsolite for this purpose.

Silica is one form of Silicon Dioxide.

The two, Silicone and Silicon arecompletly different materials.

Don

Silicon also is a commonly used alloy in iron, steel, and aluminum

This electrician I worked with many years ago grew up in a very rural area. In the late 30's they were making what is referred to as non powered crystal radio by winding wires from old coils around oatmeal boxes and getting these gray shiny crystalline rocks from along the C&amp;O railroad tracks to make their detector out of. You moved the tickler wire from the coil around on that gray shiny rock until a radio station started coming in. They had made a silicon diode detector and didn't know it?

Jim, those grey rocks were Galina, a lead mineral. Quite different, however "diodes" 1n34 being an early common one was made from silicone dioxide, quartz. The GI's during WWII found that they could use a razor blade as a "crystal" for home made radios of your design.

Don</p>

For several years I worked in an iron foundry and we used silicon as a additive to the cast iron. I would have the guy throw a shovel full in each batch


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Oh Man, are we walking back down the path. I love this stuff. I made the big old crystall radios on the oat meal box coilforms and the big slider to "tune" them I collected junk radios from where ever I coulld find them to tear apart the transformers to get the wire to wind the "coils" for these raidos. The big issue was that where I grew up, there were a number of radio stations and it was all but impossible to tune into just one. I went down to southern Ill. to my aunt's house for a couple weeks one summer and they only had one station that my radio could receive. I had never heard just one station before.

Fun days and a walk back to the early days. I wonder how many guys today know what A, B and C batteries are. that used to be common knowledge for earlyRC flyers. Rechargable batteries, years and years down the line.

Boy, this thread came a long ways from fuel line didn't it?

Don

Been there and done the A B C stuff back in the 50's but will leave it alone for we've gone way off base

Truly,,, but this information is interesting..... why do my fellow youngster disregard the wealth of information from our "elders"... you guys rock!

We did the same thing in our youth.


Ed Cregger

For sure. I wasn't playing "correct Ed", but rather "actually, here's the scoop" and to point out how radically different compounds can be from the elements that make them up, and why we use silicone fuel tubing rather than the other stuff.

Here's my pet peeve, it is more common by the day and is showing up far too frequently in print media now.

"Lose" and "loose" !!!!!!!

As in: If I lose my button, my pants will come loose. Lose = verb, loose = adjective.

I recall an RCM B&W print ad that ran for a while a few years back with the headline "Don't loose your plane in the sun again" or something like that. Really stood out to me at the time.

MJD