Clunk Line

[krayzc]

way to go RCaddiction i love test results....

[RCAddiction]

Heck....I'm not an engineer for no reason, buddy!

[rcign]

Never saw 3/16 ID Hayes....3/16 OD, yes....3/16 OD Hayes will run ANY gasser WE USE on the planet, no need for large ID fuel line...
No, I'm not an engineer, just been doing this for most of my adult life....

[JoeAirPort]

Nice test. The Hayes flexibility is as obvious as it gets in those pic's. And it stays flexible so that's why I use it for clunk line with a short brass tube in the middle. I never use the Hayes outside the tank, it's too precious for that. I use the Dubro yellow and the Aerotrend blue outside the tank. The yellow is easier to see the gas in the line and that's the only advantage for my use.

[RCAddiction]

	Quote: Originally Posted by rcign
	Never saw 3/16 ID Hayes....3/16 OD, yes....3/16 OD Hayes will run ANY gasser WE USE on the planet, no need for large ID fuel line... No, I'm not an engineer, just been doing this for most of my adult life....

Ralph - I don't believe I mentioned Hayes being 3/16" ID. If I did, that would have been a typo. Medium Hayes line sold thru Great Planes is 3/16" OD. That's the size hole I drilled in the plywood for it to pass thru for my extensive test rig (grin).

Engineer - it's what I do. I make no excuses for my degree but also make no claims to be smarter than anyone else. I take experience over a degree any day. However, unlike yourself, Ralph, I have not reached my "Adult" life yet, but I have been designing stuff for 25 yrs since engineering school. Did a few years as lead engineer for a division of Walbro for fuel injection systems. I'm definitely no expert but I do know a couple of things as a result of my career.

Joe - I've had the Hayes fall off and/or tear off brass tubing and barbs in tanks of a couple of planes. Their neoprene line is not great for cut and tear resistance. Might have been due to additives in the gasoline where I have lived. Various fuel mixes may be one reason why people have different experiences with these products. So, as a result of my experiences, and to avoid further problems, I only use Viton inside tanks and for the fuel dot line, with transparent blue/yellow stuff for vent and supply lines. Pretty bullet proof setup if one can spend the $3.50/ft for the Viton.

[zzw26n]

	Quote: Originally Posted by RCAddiction
	Clunk Lines: 1. Viton 60 durometer 1/8" ID, 1/4" OD @ McMaster http://www.mcmaster.com/#search/5119K41 2. EasyFlex @ Aerotrend http://www.aerotrend.com/shop_subcat...ea0cd769085af9 3. Hayes medium neoprene line at TowerHobbies http://www3.towerhobbies.com/cgi-bin...&I=LXK824&P=ML Vent Lines and other lines external to the fuel tank: 4. Genuine 1/8" ID Tygon tubing from McMaster. It comes in large rolls and in a real Tygon box. http://www.mcmaster.com/#search/5552K23 I hope these links are helpful.

Nice Post Lee! One-stop-shopping.

[RCAddiction]

[StevL]

As you can see from my first post starting this thread I was in need of some help with clunk lines. I decided the Hayes seemed like the best idea. I also haven't flown much in December since I'm in retail. Put about 6 flights on my yak this past Sunday, after defueling I noticed some fuel in the tank (much more than normal) but loaded up and went home. Took a much closer look today and saw the clunk laying in the corner of the tank. Pulled the tank and opened her up, the Hayes line had broken off right at the clunk. I gave the line a gentle tug and it broke off the brass end. I then proceeded to break it in half with another gentle tug.

I'm not sold on the Hayes idea any longer.

I changed back to genuine Tygon on both my gassers today. I may try another line but not till summer.

All of this may be because of fuel additives, oil, etc. but something has to change. Before someone ask I'm using Saber Pro mixed 80:1 and I'm sure my gasoline has some ethanol content.

[Tired Old Man]

No matter the line type you should change it once a year. Even the best, Viton, wears out.

[jaguar bone]

Thanks Lee for the Viton heads up - this has been educational.
Thanks for doing the testing. Did you ever soak the test samples in petrol for a while and then retest pliability?

[STLAV8R]

Who sells the Viton other than McMaster?

[RCAddiction]

I have not done a soak test on Viton in many years. I believe that there may be some fluids which can cause it to harden but not gasoline or alcohols. Typically it will swell volumetrically by a few percent and may get slightly softer.

There are many other sources for 60 durometer 1/4" Viton/fluorocarbon tubing but most are industrial and require high volume purchases.