Clunk Line

[RCAddiction]

	Quote: Originally Posted by rcign
	I buy and use Hayes...I have lots...Send me your address, I can send you 5 or 6 feet..Free, for testing..I want to silence all the naysayers...Or not.... fwiw, it's about $.50 a foot in 100 foot lengths..

Ralph, there is no question that genuine Hayes neoprene tubing works well for many people in gas. They seem to extrude a very consistent material. However, neoprene does not well survive all varieties of additives used in modern gasoline.

There are literally hundreds of fuel blends produced around the US today. They are reformulated from winter to summer (to adjust RVP), blended differently for different makers, and importantly, they are adjusted with different additives to conform to state or local regulations due to smog issues. That is why it depends a lot on where you live and what fuel is available.

If Hayes neoprene works well for the gas where you live, super. It's very cheap. However, it flat out will not work for everyone. When I lived in Chicago, Hayes neoprene would begin to decompose with the fuels I had available. Others have reported the same problem in other parts of the country. Neoprene is NOT used in Automotive applications for this reason. Viton is. Viton is simply far more tolerant and is one of the more cost-effective materials that I used when I developed automotive and light truck fuel systems.

Summary:

• Hayes - cheap, available thru hobby distribution - works very well in some parts of the country. It may work for you (or may decompose and get sucked into your carb.).
• Viton - more expensive, available thru McMaster, etc, works very well in all parts of the country. Probably costs $1 per fuel tank. I do not see the rationale of using anything less.

[JoeAirPort]

I had Hayes gunk up my carb screen on two different engines. I can't use it in the Milwaukee area. Tygon or Viton for me.

[Dr. Yankem]

[quote=JoeAirPort;626165]I I use a brass nipple in the middle of mine to keep it from folding in half and going to the front of the tank.quote]

I'm not sure I agree with preventing the fuel line from doubling in half and going to the front of the tank. I set my tanks up so that the clunk line is able to rotate to the front and back cleanly without hanging up anywhere. If I need to go into a spin at the end of the second flight of an Imac sequence, then I want the clunk to come to the front of the tank to pick up the fuel to prevent a fuel starved flame out.

[JoeAirPort]

Never had a fuel starved flame out myself but whatever works for you is ok by me.

[Truckracer]

Excellent post RCAddiction! I continue to use Hayes line for some clunks but keep a close eye on it as I've had problems. If left in my tanks too long (over one season) it turns brittle and can be pulled apart like a tapeworm ... in segments. It also turns slimy when first installed and has to be secured well with barbs and ties or it will fall off the brass tubing.

I just ordered some Viton and look forward to trying it if winter ever goes away.

[TooBizzy]

	Quote: Originally Posted by RCAddiction
	Ralph, there is no question that genuine Hayes neoprene tubing works well for many people in gas. They seem to extrude a very consistent material. However, neoprene does not well survive all varieties of additives used in modern gasoline. There are literally hundreds of fuel blends produced around the US today. They are reformulated from winter to summer (to adjust RVP), blended differently for different makers, and importantly, they are adjusted with different additives to conform to state or local regulations due to smog issues. That is why it depends a lot on where you live and what fuel is available. If Hayes neoprene works well for the gas where you live, super. It's very cheap. However, it flat out will not work for everyone. When I lived in Chicago, Hayes neoprene would begin to decompose with the fuels I had available. Others have reported the same problem in other parts of the country. Neoprene is NOT used in Automotive applications for this reason. Viton is. Viton is simply far more tolerant and is one of the more cost-effective materials that I used when I developed automotive and light truck fuel systems. Summary: Hayes - cheap, available thru hobby distribution - works very well in some parts of the country. It may work for you (or may decompose and get sucked into your carb.). Viton - more expensive, available thru McMaster, etc, works very well in all parts of the country. Probably costs $1 per fuel tank. I do not see the rationale of using anything less.

Great post right here! Thanks! I have never had issues with Hayes probably because of the area I live in. I didn't know that the additives is what caused the problems. After posting in this thread I looked at ebay for Viton. I've found it for about $3 bucks a foot. Maybe I need to look into this further? I don't want the gas changing on me unknowingly! If it does, might not hurt to be prepaired????

Question then: If Viton is advertised on Ebay As VITON....Will it be VITON or could it possibly be a cheap knockoff that could give you problems in the long run? Just wondering? I've also seen it advertised for $8.50 a foot.....Huge price spread!

[jaguar bone]

Viton is a regesterd product name - so should be as safe as COKE.
RARC now handles the product in 24" lengths for $12.00 delivered.
http://www.flyinggiants.com/reviews/...uct=337&cat=44

Buyer beware as the tubing has no logos or defining marks embedded into it.

"Let's talk" on qtys 5 and over.

[dabrandt22]

OK, I live in Northern Illinois, and fly my gassers from March - Oct. If I'm willing to change out the McMasters real-stuff Tygon once per year, am I good-to-go, and not running any uneccesary risk?

[Truckracer]

	Quote: Originally Posted by dabrandt22
	OK, I live in Northern Illinois, and fly my gassers from March - Oct. If I'm willing to change out the McMasters real-stuff Tygon once per year, am I good-to-go, and not running any uneccesary risk?

Other than getting overly stiff over time, I've never heard of many problems with Tygon.

[jaguar bone]

	Quote: Originally Posted by dabrandt22
	OK, I live in Northern Illinois, and fly my gassers from March - Oct. If I'm willing to change out the McMasters real-stuff Tygon once per year, am I good-to-go, and not running any uneccesary risk?

I would think yearly is very safe interval in my experience. Should probably plan on changing out the stopper gasket too if removed though dabrandt.

Feel lucky to have "down time" weather - as I find a good going over ALWAYS seems to reveal some potiential disaster in the workings on my planes!

[Stripe]

Thanks for the feedback the Hayes stuff will be on my next shopping list.

Stripe

[bobrev06x]

wow rcaddiction, thats some great info and thanks for sharing that with us. i used hayes last year and that was my first season with gas so i dont have anything to report right now on the setup that i'm using. i do know that i'm going to be changing fuel line on my entire system before the season really gets going here in new hampshire, whether or not i'll continue with the hayes depends on what other guys are doing i guess. i originally used the hayes because of what i read on here last year and how the guys liked it. now i'm reading different so who knows? doesnt bother me to change it out. i'd rather be safe than sorry.

[RCAddiction]

Glad to share the info. I hope it helps my fellow fliers, I really do.

Tygon (real Tygon brand as I've posted elsewhere) is ok stuff. If it's easier for you to get, and if you don't mind changing it regularly, it's really ok. It is still used in outdoor power equipment fuel tanks, but primarily for fuel lines that don't need to flex much and are not exposed to much heat (it will melt). Genuine Tygon is not going to clog your carb, but if it stiffens up, of course you might lean out your engine or cause it to quit.

I use Tygon for all of the external fuel tank lines.

Viton - be careful. Unless it is from a reputable seller, it could be rejected material or even misrepresented Buna-N or Nitrile rubber. You cannot tell by looking at it whether it is the real deal or simply Buna-N or Nitrile rubber. Note: there are many equally good unbranded materials that are chemically identical to Viton brand which are used in industry, but are spec'd by experienced engineers. They are sold under the generic name Fluorocarbon or Fluorocarbon Elastomer.

For the couple of dollars saved on eBay vs buying known Viton brand tubing, it's likely not worth it. Be careful to get the lowest durometer (measure of softness) and thinnest wall available so that it flexes well in your fuel tank. The softest Viton grades are typically 60 durometer. 70 or 80 durometer are too stiff for our use.

[dabrandt22]

	Quote: Originally Posted by jaguar bone
	.....Feel lucky to have "down time" weather...

Jag...."lucky to have down time"??.....hmmm......grrrrrrr....count-to-ten.........relax......breath......you're still a Hoser.......LOL

[kenhiraihnl]

I agree 100% with RCAddiction's comments regarding Viton and Gas w/ Ethanol. My state is surrounded by water, with lots of personal watercraft. Some gas stations (usually near marinas) carry 'Classic' gas (no ethanol). Additives in gasohol sold here is probably the cause of problems in older engines and accessories. Btw, I use this Viton, but still solder barbs on the brass tubes, and zip-tie...
http://www.mcmaster.com/#5119k41/=63d6al