Shellac vs avgas

[flyguy]

It is my understanding that all the original gas gage float corks on Taylorcrafts were coated with Shellac. I have never heard of a a case where avgas disolved this coating. The EAA STC specifically warns that the alcohol in car gas will dissolve the shellac on these floats. I did not read that warning until after using car gas and finding my float coating in my fuel strainer along with bits and pieces of the cork float. Required a complete cleaning of the fuel system. Alcohol is the solvent used in shellac. Again I rest my case.
D.

[Frank DeBartolo]

Re: Shellac vs avgas

Amen!!!!!:

[Robert Lees]

Re: Shellac vs avgas

I find that untreated cork, replaced every few years or so, is impervious to all fuels.

On another subject, the local wine & beer brewer does a wonderful line in large corks, suitable for demijohns.

[VictorBravo]

Re: Shellac vs avgas

Todd Petersen says that any fuel dealer, flying club, FBO, etc. can buy auto fuel without ethanol. All it takes is a large enough order to meet the distrubutor's requirements. But if one FBO will offer the non-additive car gas, all the STC owners from miles around will go there to fuel up. Problem SOLVED!

[crispy critter]

Re: Shellac vs avgas

It is my understanding that all the original gas gage float corks on Taylorcrafts were coated with Shellac. I have never heard of a a case where avgas disolved this coating. The EAA STC specifically warns that the alcohol in car gas will dissolve the shellac on these floats. I did not read that warning until after using car gas and finding my float coating in my fuel strainer along with bits and pieces of the cork float. Required a complete cleaning of the fuel system. Alcohol is the solvent used in shellac. Again I rest my case.
D.

Read the STC.It clearly states not to use auto gas containing alcohol.We have 7 gas stations in the city limits of West Liberty and I have yet to find a drop of alcohol in the gas from any of them.I like auto gas,for us it's less trouble and easier on the engine,plus the nearest avgas is 45 miles away by air and 65 miles by car.I have nothing against avgas,I just don't use it unless I have to do so.It's kinda like T-crafts verses J-3 cubs,i.e. there's nothing wrong with either of them,they do the same job but one just does it a little better for a hell of a lot less money .

[mulwyk]

Re: Shellac vs avgas

Is it true that epoxy coating the float will cure the ethanol problem? Has anyone tried this?

Bob Gustafson

[mhorowit]

Re: Shellac vs avgas

Is it true that epoxy coating the float will cure the ethanol problem? Has anyone tried this?

Bob Gustafson

That might cure the cork float problem, but I believe there are also problems internal to the carb, and possibly with any rubber tubing - Mike

[crispy critter]

Re: Shellac vs avgas

Once again,this why the STC clearly states no alcohol.

[selje]

Re: Shellac vs avgas

Coating or painting the cork with "Hot Fuel Dope" from a hobby shop has worked well for me.

[flyguy]

Re: Shellac vs avgas

One just caught me off guard the other day. I'm hot rodding/restoring a 74 Camaro Z28 and being the clever guy that I am I used some Permatex Aviation Gasket Seal, you know the liquid brown stuff. Usually use isopropyl to clean hands ect. Only had some ethanol (denatured) handy so I used it and a little light went off. Boing. Can't use this on auto anywere california gas is going to touch it. OOps. Another reason not to use gas with alcohol for avgas.
D.

[TimHicks]

Re: Shellac vs avgas

I tried coating my cork with JB Weld (epoxy) after hot fuel proof dope didn't work.

I thought JB weld would be the ultimate, although heavy solution. It lasted 18 months then started to bubble and separate from the cork. I peeled it off before any pieces got into my tank.

Since then, I've been using an uncoated cork. It's been about 5 years. Works fine.

[Dano"T"]

Re: Shellac vs avgas

I also use an uncoated cork....just stick a clothes pin on the wire to hold the cork up out of the fuel if the tank isn't topped off.

[M Towsley]

Re: Shellac vs avgas

I've been researching an outlet for a float that came on my T-Craft. It is black and of a synthetic material, similiar to a closed cell foam that is solid and very smooth, (for lack of a better term). Take a look at a float for a car or boat gas gauge, and that is what the material that came on my gas gauge looks like. I have found the manufacturer, but they will not sell direct. They custom make floats for auto/boat manufacturers out of large blocks of this material. I think whoever had mine pirated it from their outoboard motor gas tank. This float does not have to be coated and is impervious to mogas and 100LL.