Neoprene, Tygon, and Viton UV Resistance
 

Had a plane that wouldn't start last week. The plane does not have a cowl on it. I found the portion of the fuel line thats not inside the fusealage was cracked, especially the top portion that is exposed to the most light. The rest of the line (the part always in the dark) is fine. Its 2 years old. Its Hayes neoprene. The searches i've done on this forum talk about a lot of problems with this fuel line, but I'm wondering if the problems other people have had, have been deterioration from fuel exposure or UV light exposure? I've noticed the same problem with the same hayes line on my fuel jug. I've looked up the specs on neoprene, tygon, and viton, and they all claim to be UV resistant. Does anyone know if Viton and tygon have any better UV resistance than neoprene? I use Viton inside the tank, and I will use it everywhere if it will hold up to UV light. From what I've experienced the last few years and what I've read here, nothing seems to work very well. Is there any good solution that will last several years or is it best to just buy the cheap stuff and replace it every year?

RE: Neoprene, Tygon, and Viton UV Resistance
 

Neoprene i not especially UV resistant, but getting a couple years before replacing is not bad. Tygon stiffens with age and the low grade stuff stiffens and expands a litle after exposure to gasoline. Viton is as good as it gets but costs more. It comes down to what you want to spend.

RE: Neoprene, Tygon, and Viton UV Resistance
 

Most neoprene is more UV resistant than it used to be many years ago.

But the sun is not kind to anything in the long run.

RE: Neoprene, Tygon, and Viton UV Resistance
 

ive had the best luck with blue line(Aerotrend) when compared to neoprene, but it has been discontinued...

RE: Neoprene, Tygon, and Viton UV Resistance
 

I just use good ol' Dubro tygon. It's a good idea to keep the canopy covered at the field if you have UV problems. I always leave a half tank of fuel which keeps the tygon soft.

RE: Neoprene, Tygon, and Viton UV Resistance
 

I replace my plumbing every other year no matter what. Just part of the regular maintenance. I use Tygon on my gasers, and have had relatively good luck with it.

RE: Neoprene, Tygon, and Viton UV Resistance
 

I've had both Hayes black seamless neoprene, and Tygon deteriote, when both were well covered under cowl. Two years is much too long to go without changing it out. The Hayes neoprene became perforated with dozens of tiny holes that eventually opened, and sucked air. The Tygon became hard as glass, and just broke. I don't think that UV is the problem, it's just that two years is much too long to wait to change it out.

Ed

RE: Neoprene, Tygon, and Viton UV Resistance
 

Okay, its sounds like neoprene and tygon are only good for 1 season. Has anybody actually used viton for a long enough time period to know what the expected life should be in our application? I'm happy to pay more, if it would last for 4 or 5 years.

RE: Neoprene, Tygon, and Viton UV Resistance
 

Not true.

The right Tygon for the job holds up quite well. Look for "Type F" Tygon at better industrial supply outlets. It's good for a couple years. Another Tygon is the nylon reinforced version. It will last much longer. Again, it's in what you want to spend.

Been using Viton for about 5 years now, along with Tygon for much, much longer. Both work just fine for me for as long as I need them to last.

RE: Neoprene, Tygon, and Viton UV Resistance
 

If you keep some fuel in your tank the tygon will stay soft and last years. Next time I re-plumb my tanks (next winter), they get the Viton. I have 3 feet of it sitting in my shop.

As far as neoprene goes, I won't ever use it again....not even for one season. Gummed up my carb screens really bad.

RE: Neoprene, Tygon, and Viton UV Resistance
 

I have been using Tygon for years. I change it every year due to stiffness. This year I am using all 3, Neoprene, a Viton equivalent, and Tygon. I am now worried about the Neoprene after reading the above. Viton is a brand name, btw.

Neoprene is extremely flexible, almost too flexible for my tank. I had to extend my brass tubing deep into the tank to keep the clunk from dropping forward.
The Flouroelastomer hose (Viton equivalent) I bought from Duda Diesel is not very flexible and will not work in the tank. I use it outside. There are different grades of Viton or Vitube that have different stiffness. The stuff I bought from Duda says it is 65A, Grade A at $2.75 per foot. There is apparently a more flexible Vitube: Type B, 60A. The 60 is the durometer gage, lower being more flexible. If you search around the net you will get more information. [link=http://www.mcmaster.com/#viton-fluoroelastomer-tubing/=83c457]Mcmaster Carr[/link] sells it for like $3.79 per foot. I will try this next.

RE: Neoprene, Tygon, and Viton UV Resistance
 

Ed and JoeAirport,
You guys reported problems with Neoprene. Just curious, do you use gasoline with ethanol?

RE: Neoprene, Tygon, and Viton UV Resistance
 

Unfortunately ........... Yes.

Ed

RE: Neoprene, Tygon, and Viton UV Resistance
 

Where can you find fuel without ethanol in the State of Ohio?

RE: Neoprene, Tygon, and Viton UV Resistance
 

VP Racing Fuels at about $18.00 a gallon. What a deal. Easier and much cheaper to use Tygon and replace the lines once every year or so. Viton does not seem to be affected by minor amounts of ethanol. One should be checking thier fuel systems annually. If replacing a little plumbing once every year or two is an intolerable expense they need a different hobby. Doesn't matter how many planes they have. It runs hand in hand with paying $5.00 for a plug ecery couple of years. Some find plugs too expensive, yet they would blow a glow plug or two every week or so.

Sorry, I just find the task of replacing consumable parts periodically to be part of the hobby experience and not something to complain about.

RE: Neoprene, Tygon, and Viton UV Resistance
 

I've a friend who has VP come up from Texas periodically with 1500 gallons of gasoline. Seems like that would be a big hit for your hot rod?

RE: Neoprene, Tygon, and Viton UV Resistance
 

I use Coleman lantern fuel!

Sincerely,

Richard

RE: Neoprene, Tygon, and Viton UV Resistance
 

Pay attention to the bearings with white gas. I heard the story at the field that it causes pre-ignition which puts extra stress on the bearings. At the end, the bearings have to be replaced. Not once, but twice.

RE: Neoprene, Tygon, and Viton UV Resistance
 

I've listened closely to the guys running Coleman at the field and I've never heard any preignition

RE: Neoprene, Tygon, and Viton UV Resistance
 

Yep.

RE: Neoprene, Tygon, and Viton UV Resistance
 

Ok Guys

Will add my 3 pennies worth as I have used all 4 of the type's mentioned above and std pump gas with all the sbove complaints,

So for the last 5 years I have gone to the following combo Tygon type F and avation gas 100 oct ($4.45 per gal) mix @ 50:1Klota model sysn plus 1oz of seafome per gallon I don't leave any fuel in the tanks and I do not run the carbs dry with 6 monthe of winter I have had no gumming etc.

Hope this helps
Cheers Bob T

RE: Neoprene, Tygon, and Viton UV Resistance
 

I am sincerely interested in this "story" as I have never heard of it before, and I have researched all of the forums and asked the cons of Coleman fuel (I know the pros, that is why I use it). Does anyone have first hand or documented evidence of bearing failure from pre-ignition caused by Coleman fuel? Please respond, for my own understanding.

And what does it mean to have to replace the bearings twice, not just once?

Thanks.

Sincerely,

Richard

RE: Neoprene, Tygon, and Viton UV Resistance
 

Richard,

It is just that you need to periodically check the bearings to make sure there is no extra play, or extra wear.

The engine involved is a DLE 50. Bearings have been replaced twice for no obvious reasons other than the fuel used. If I get a chance to talk to the owner of the engine, I'll get the detail for you.

qc

RE: Neoprene, Tygon, and Viton UV Resistance
 

What's the octane of Coleman? DL-50 calls out 87 octane or something close.

Nevermind. 50-55 octane. Wrong fuel for that engine. I would never use the stuff personally.
http://en.wikipedia.org/wiki/Coleman_fuel

RE: Neoprene, Tygon, and Viton UV Resistance
 

If anyone has used viton (inside the tank) long enough till it had to be replaced, did it need replacement because if was too stiff, or because it was getting cracked/checked?

The reason I ask is I would like to have an idea (without taking the tank out and apart for inspection) when the line will become too stiff and cause the walbro clunk to not be in good contact with the fuel.

I've found that on small engines (20cc), I have to use a 12 to 14 oz tank in order for the viton line to be long enough to flex enough. I then position the vent line around the middle of the tank so I only fill it about half way. Has anybody used an 8 ounce tank with viton successfully?