What is everyone using for the clunk line inside their gas tanks?

Tygon goes hard after time submerged in gas & I am wondering if this will cause problems in a IMAC type model? Or should I be using something else?

Over here, if you want the best.....this http://www.mcmaster.com/#viton-fluor...tubing/=ik5d10 is what we use....

The ethanol in today's gas seems to be causing the problem. Either change it out every year or so or use Viton, which seems to work with all fuels. Viton can be bought from McMaster carr for one. Good luck.

+1 on Viton

Tygon seems to harden when it's been in gas then dried out, I try to leave just a little fuel in my planes and I've had the same piece for 2 years in one of my planes and it still clunks around fine. By just a little bit I mean I have a Sullivan tank and I just leave gas in the little front part as I store the plane on it's nose (any more and it seeps through the Dubro stopper or gets through the vent line) since I store them in a tiny bedroom that's also my office

Which size do you usally use?

Chris923

Myself, I use 1/8" I.D. x 1/4" O.D., soft, & i would guess the most popular......others may vary according to their plumbing requirements....

Hey Boltman,
for the clunk I use ryobi fuel line it's opaque grey, after two years it's still perfectly flexible. It's very dear so I use tygon for everything else
You can get it from mower shops, they also sell felt filter clunks which are great.

Thanks for a solution that I can easily source here in the land of OZ. I will give that a go.

forgot to mention, I keep my tanks full when stored, it seems to keep the lines soft.

Tygothane. Polyurethane tubing, Formulation C-210A. Here in the states I get mine from McMaster Carr. Down under I have no idea who carries it. Search the formulation and make sure it is the correct one. Other polyurethane formulations don't work......

No need to keep any fuel in the tank to keep this formulation supple. My original experimental tank is still in service 3 years and running, without any issues. I use the 1/8" x 3/16" size and it is the most flexible stuff I've found (including viton in 1/8x1/4 size). It is about 1/10 the cost of viton but that's minor issue since one only uses a couple feet to plumb the gas supply. You have two viable options

Hey boltman, you can get viton from Perth they also sell on ebay
http://www.ebay.com.au/itm/Viton-Rub...item2314e5011d

Now you have made it really easy! Thanks, I will order some there.

Cheers

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+2 to that, I will be ordering some my self. Thanks for making it easy to find.

Cheers

I use my poly line that I carry, works great and doesn't stiffen up like tygon. For the Clunk I really like walbro clunks.
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Or you just go with a Rotoflow tank and never have a worry of this again.

See link below. Handful of people at my field using them with glow or gas and no worries.

Check it out.

http://www.jlproducts.net/ProductRotoFlow.html

I have had mine now for the season and Model Airplane News just did a review on them. Fantastic.

Steve

Is the Poly line like the kind they use in Hospitals for IV lines? Thanks

It's different as most hospital stuff is nitrogen/air rated. <div>
</div><div>All info can be found here. http://www.vital-rc.com/fuel-line.html if you're interested. I buy all my viton from McCaster as it's another</div><div>reliable source. </div><div>
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Rotoflow here as well.

Delete post. I discussed this already, above

Ya....how you going to delete post???? Even the post you made will be here forever...... you can edit it....thats about it!

I cap my vent with a fuel dot, and use a fuel dot for the fill line, so I can leave gas in the tank and not have it leak or stink. Should keep the lines flexible for quite some time.

Cap'n, you probably should not use the med tubing. Looks nice but I think you would find the material falling apart after a few months. It's primary use is saline delivery or air delivery

You are most likeley right....I do not use med tubing....for a vent it may work in a pinch. I used new Hayes neopreme line in the gasfuel tankand it did not last a week. The rest of the line I use on a hand crank gas pump....works fine for that because the fuel is not in it only when using thepump. Capt,n

There are sooo many neoprene compounding formulations, it would really be like needle/haystack to find a neoprene line that works. Neoprene was originally invented for gasoline fuel lines so the base material will work. Except, it must be compounded will alll kinds of fillers to make it usable in extrusion equipment. Compounding makes all the difference.

Cap, you may want to check the fittings of your hand crank pump. I suspect you will find stress cracks on the neoprene tubing. Let me suggest that you buy yourself a roll of the PolyU from Mc Master Carr. You won't be disappointed.....Inside the tank or out, makes no difference....