CafeenMan

I'm pretty new to gas engines. I've built a few planes that use gas but they were for other people, never for myself. So pretty new is giving me too much experience. I'm actually a complete noob to gas.

OK, so I keep seeing over and over that tygon lasts a season or two and then needs to be replaced. Then why use it? What's wrong with using neoprene or whatever fuel line has been used for years? Seems the tygon is more expensive and has a short lifespan.

I really hope the answer is because people think the clear amber color counts as bling.

All Day Dan

My Feedback: (5)

Use this. Dan.
http://www.mcmaster.com/?orderview=n...19/134/=rjr30w

Truckracer

My Feedback: (19)

Over the years, vinyl based lines such as the yellow Tygon F-4040-A became the standard for gas lines as they had a reasonable price, they are tough and abrasion resistant, resistant to leaks and splitting, do not degrade when used with most gasoline formulas, etc. Overall it is just a good all around compromise and remains so today. The problem seems to be with the many gasoline formulas that exist across the country today. Some seem to cause the line to get hard in a short period of time. Some users have found that leaving their tanks partly or completely full of fuel eliminates or reduces this problem. Other users have had problems no matter what they do! Then there are users that get along just fine with Tygon and that is my case, at least for lines outside the tank. I have airplanes where the lines are well over 5 - 7 years old and they still have reasonable flex. So you see, not everyone has problems with Tygon tubing! Some people blame the ethanol in most gas formulas for their line problems but other users have had problems with non-ethanol containing fuels so the verdict is out on that subject.

Clunk lines inside the tank are another issue as they seem to harden much quicker than outside lines. For that application, the very expensive Viton tubing seems to work extremely well as it is extremely resistant to damage from most any fuel we may use. It is pretty much an install and forget product as it is that good. The only problem I've had with Viton is the available line sizes and the associated reduced flexibility don't seem to lend themselves to short clunk lines in small tanks ..... small being tanks 12oz. or smaller. Viton is an excellent all around fuel line and overall, about the only thing I can say bad about it is its cost. The line is black in color and is opaque.

Some people are using Tygothane C-210-A polyurethane line, This line is cheaper than the yellow F-4040-A line and it seems to retain it's flexibility better. This line also seems to really grab fittings though clamping should still be used. I've used it in one airplane and see both advantages and disadvantages of this line compared to the yellow line. This line can vary from clear to light blue in color and is transparent. MTK here on RCU sells this line.

McMaster Carr also lists a blue, Fluorosilicone Rubber line for use with gasoline. This line is more expensive than Viton but is more flexible, extremely flexible in fact. It feels very similar to glo fuel line. I have some of this line but have not yet had a chance to try it in an airplane. It does appear to have potential for being a good clunk line in small tanks. It is a very pretty blue color though and is opaque. Some postings on forums have said this is the same product once sold by AeroTrend but it is not.

All the above lines and many more are available from McMaster Carr and a link was provided by All Day Dan.

Lots of choices and fuel line "bling" was never a consideration for my airplanes.

w8ye

My Feedback: (16)

I use the Tygon 4040A as it is readily available around here. It has a reasonable life expectancy and I have no reason to change from using it. It will last more than a couple years inside a tank in this area.

CafeenMan

McMaster-Carr is one of my favorite places on the net. The person who referred me there several years ago said, "Go to McMaster-Carr! They have EVERYTHING!!!!" Well, not exactly true, but yeah...

Thanks for the info on the lines, Truckracer. The link Dan provided had several lines and I wasn't sure which ones he was talking about. I already have enough tygon for a couple planes so I'll probably use it but I'll also probably order a couple other types to check them out.

Deandome

My Feedback: (1)

thanks for the info...I'm getting ready to put fuel line in my first gasser. What size do I want, ID/OD-wise?

Truckracer

My Feedback: (19)

Common sizes are 3/32" and 1/8" ID. !/4" is typical OD. I prefer 1/8" as it seems to fit the wide range of fitting sizes where 3/32" seems a bit too small for my taste. Use DuBro solder on barbs on brass tubing and secure the lines with a nylon tywrap or other clamping method at all fittings. Either line size will flow more fuel than is necessary for all but the largest engines.

CafeenMan

I've got some viton and fluorosilicone in my cart at McMaster-Carr. 1/8" ID / 1/4" OD. And as I said, I've already got some tygon. Any of them should work. What I'm looking for is not just what works but what keeps working the longest. Time will tell.

Truckracer

My Feedback: (19)

Cost no object, I think viton would be my choice. The fluorosilicone being like many silicone based lines will be more delicate. As long as you're ordering line .... you might try the Tygothane line also.

CafeenMan

Between the five feet of viton and the five feet of fluorosilicone, the order is already forty bucks plus shipping. Ten feet of tygothane is a little over seven. What's good about tygothane?

Truckracer

My Feedback: (19)

Some claim it doesn't get stiff like Tygon does when used with some gas formulas though when new it isn't quite as flexible as Tygon F 4040 A. I found it really grips the line fittings but required a bit of heat from a heat gun to install the line in the first place. It is cheaper than Tygon F 4040 A.

3136

Truck is right thygothane c210a isn't as flexible when new, if you use a walbro felt clunk it has more than enough weight for a reasonable size tank.
I checked my clunk line that has been in place for 3 years, it's still like new.
I don't know if it's the line or quality of fuel here, but it works great for me.
I don't know why it's so cheap, it should be 4 times the price it is.

CafeenMan

What's the reason for a felt clunk? Is gasoline just that much dirtier than glow fuel or is there something other reason?

3136

Filtering crap out of any engine is a good idea in my view, the walbro clunk is nice and heavy, it will draw every last drop out too.

CafeenMan

I'm a big fan of filtering. I normally have two filters from the fuel can - one is the pick up and another inline. Then I have a filter in the line between the tank and the carb. I used to use the sintered bronze filters but I stopped using them. I never had any problems with them as I recall and probably just forgot that I use them during one of my long breaks from the hobby.

Is that type filter something McMaster-Carr would have or is it hobby-specific?

3136

I'm not familiar with Mcmaster as I'm on the other side of the planet, yard equipment shops sell them as they are used on line trimmers and mowers. Some hobby shops sell them too.

CafeenMan

Driving home tonight I discovered a lawn mower/small engine repair shop about 3 miles from my house. I'll stop by there and see what they've got. I found the felt filters at Chief's Aircraft for about $5.00. I need some other stuff (mostly props) so might just order it from them.

Thanks for all the info.

3136

I just looked at cheif's site, that one is different to the ones I get, not sure of their weight, maybe take a photo of the picture I posted with your phone and take it to the yard shop so you get the right one.
The ones at Cheif may be ok, I've never used them, maybe someone else could chime in?

CafeenMan

Honestly I'm not that concerned about filtering in the tank because as I said, I usually use three filters anyway and if the fuel in the jug is actually dirty then I'll filter it into a clean container and not keep on using dirty fuel. But yeah, all information is welcome. I have a lot to learn here.

The plane is an Aeroworks Checkmate with a DLE 55 RA engine. I just ordered servos. I also ordered a Fromeco battery for the onboard pack and will use either a NiCd or NiMh pack I already have for the ignition.

I'm still trying to figure out why guys strap on a huge long vent line on top of the tank in a big loop. What's that all about?

3136

The reason I prefer the clunk I posted is that it's nice and heavy.
C210A is a little stiffer than Tygon 4040 when new but it appears not to stiffen over the years like tygon does, BUT, you must use a heavy clunk.

The loops at the top rear of the tank are to reduce the amount of fuel that pisses out in maneuvers.

BTW nice plane you bought, or should I say nice model.

CafeenMan

I hope they remember to put air holes in the crate. I don't want to explain why I have a deceased, blue model in my shop.

raptureboy

The nice thing about the felt clunks is they will hold fuel so that even if it comes out of the fuel during manuevers the engine won't quit, but it may be hard to get through the opening of the tank or not at all if it is small tank. I got lucky and bought a 100' of tygothane off ebay for $25 it lasts and lasts but it is stiffer and can be kinked easier than tygon if you bend it to hard. It grips like pit bull on barbed fittings.

hairy46

My Feedback: (1)

All ears on this thread, new to gas"

MTK

The Walbro Klunk does a fine job.

Well, I discovered the Tygothane C210 formulation several years ago and discussed the finding in these pages. I currently sell the 1/8" x 3/16" size clear tubing but a fuller array of sizes is available. For models, I doubt anything larger is required tho. This size doesn't need the heavy Walbro klunk because the wall thickness is 1/32" not 1/16", and is inherently more flexible. Any model klunk that weighs what the typical Glow klunk weighs, works fine. But the filtering capability of the Walbro makes it worthwhile.

Someone asked why so cheap? Let me tell you having worked in that business in the past, it isn't so much that Tygothane is cheap as much as the other yellow tube is way over what it should cost. Polyurethane as a plastic/rubber material stock actually costs more than the PVC stock the yellow tube is made of. The oils (plasticizers) in that tubing make it very flexible at first but as the gas leaches out the oils, the material becomes stiff.

Neoprene was the original synthetic rubber designed for gasoline for automotive use. But if it isn't compounded correctly with the proper antioxidants and antiozonants, then it won't do us users any good.

Speaking of filtering the gas, I would say definitely a must do. Many gas tanks at gas stations are full of dirt and that eventually finds its way to our gas cans. Even Aviation Gasoline has the problem. Just recently I was looking at my gas cans (all Avgas BTW) and found residue on the bottoms that had to come from the gas tank at my local municipal airport.....

McMaster Carr sells some terrific nylon filter medium, around 200 mesh, that I fitted into the nozzle of my main gas can. I used a double layer of the material right in the nut that attaches the flex nozzle to the can's body. It works great.

For extra peace of mind I also fitted some of this material into my funnel I use for tranfering from the gas can to the field can on my flight box. Try it, it's simple and works well..... Look up "Nylon Mesh"; the bigger the number the smaller the holes....

Truckracer

My Feedback: (19)

[QUOTE=MTK;11787412]
>>>>>Speaking of filtering the gas, I would say definitely a must do. Many gas tanks at gas stations are full of dirt and that eventually finds its way to our gas cans. Even Aviation Gasoline has the problem. Just recently I was looking at my gas cans (all Avgas BTW) and found residue on the bottoms that had to come from the gas tank at my local municipal airport.....