shellac in my fuel system

[taylorcraftbc65]

Re: shellac in my fuel system

Hank,
I have tremendous respect for your knowlege, and I really need your advice on something.
It looks like, somehow something with alcohol found it's way into into my cowl tank, and melted the shellac that was painted very heavilly on the cork bobber.
I did not knowingly put any "real" autofuel in the plane, the only things that I put in the tank were 100LL, and certified for aircraft use, sold at the pump at the airport, autogas.
Automobiles run for hundreds of thousands of miles on ethenol laced fuel, and I am wondering about running hoses that are made of automotive fuelinjector hoses with aviation ends swaged on. The fuel gauge would be replaced with a bobber that was impervious to either 100LL, or alcohol laced autofuel.
I would NOT do this to intentionally run car gas, but to make the concequences of a misfueling minimal, or non existant.
I'm not overly concerned about treading on the FAA's toes with the new materials, as I am with making a fuel system on my plane that is not so vulnerable to alcohol.
Your thoughts sir??? Brie

[Hank Jarrett]

Re: shellac in my fuel system

I would have to look at the rules again for owner produced parts to be sure, but making a new fuel float doesn't seem like a problem. It needs to be equivalent or better than the original, but how many people working on our planes even know what WAS original? If you replace your float with one that is safe for all fuels I can't imagine your mechanic having any problem, but that is the key, get him/her involved first and get their buy in before you change things.
The fuel lines can be addressed by changing them out if they are damaged. Again work with the person who will be signing it off. I put all new lines in my plane and used all Aeroquip lines and fittings. The beauty of these is the race car guys use them too, and they run on pure alcohol. The only problem I ran in to was the local ramp expert who kept telling me I had to use all steel fittings for fire safety. I have decided to ignore him since the gascolator and carb are aluminum, and as one of the tribe pointed out, the back case on some of the 65 hp Continentals is actually MAGNESIUM! I am putting fire sleeve on the lines, but that is because I think it is a good idea. A few more minutes to get on the ground in a nightmare situation.
Main thing is, do it safe first and get your A&P or IA to buy in to the solution first. Safe, then legal.

Hank

[flyguy]

Re: shellac in my fuel system

Brie, I think you will actually find it difficult to buy a new hose that is not resistant to almost anything, including ethanol. The major tonnage of fuel lines are made for road vehicles using some alcohol now and I believe most everything is of all-fuel-resistive type material.

I say this from having checked both stock in stores and in listings in catalogs and on the Internet.

If you find it necessary to completely protect your aircraft there are at least 3 other items.

1. Make sure there is no gasket sealant on your carb gaskets. If there is and that problem you had was due to ethanol it will dissolve the sealant and make another mess, this time in your carb. (ask me how I know this, Chuckle.) There is only one sealant that I have found that is not alcohol based and it is hard to find. There should be no sealant on carb gaskets.

2. Ethanol will dissolve thread sealant because all but the one mentioned above are also alcohol based, or soluble like Permagasket and such. (to the best of my present knowledge from all the looking around that I did.)

3. Your needle valve in the carb needs to be steel. I think delrin is OK also, but check with someone on that.

Darryl

[Ray36048]

Re: shellac in my fuel system

Type D hoses are Teflon with SS braid.

[Hank Jarrett]

Re: shellac in my fuel system

The SS Braid covered hoses sure look nice too. Then they look like C**P when you put the Fire Sleeve on them.
Oh well, the engine compartment isn't supposed to be for beauty, even if some of you guys have them that look like they are.
Hank

[cvavon]

Re: shellac in my fuel system

Tribe

I jest had the need for hose fittings to use on airoquip 666 teflon hose for my brake conversion my local airoquip store had the AN reusable stanless end for an-4 37 deg flair air craft spruce price in 2008 catalog 38.80 at store in tn 2010 price 9.88 also there hose is much cheaper and also he said he can get fire sleeve airoquip stores are all over pays to shop

[NY86]

Re: shellac in my fuel system

Delrin needles are impervious to alcohol and would work fine in your tractor.

[Guest]

Re: shellac in my fuel system

Hank,

Back in the forties when my mom was flying she took off with the storage cap on, at least for a little while until the vacuum overcame the flow. She landed in the airport parking lot. I think she was in a Chief at the time.

Cut a slice out of the gasket in the storage cap. Make it just big enough to create a vent but not so big as to make the gasket come apart or fall off the cap.

Been working for me for many years.

Dave