If you knew a way to make flying your plane safer and more reliable wouldn’t you do it? Now there is a 21st century solution that addresses problems for carburetor floats.
Early carburetors had solid cork floats. Solid cork wouldn’t leak but it would absorb fuel and then became too heavy to work right.
Hollow brass floats followed around the time of World War I. Their egg-shell-thin half-pontoons were soldered together. Then the pontoons were soldered to brass frames. They wouldn’t absorb fuel, but the soldered seams were not always dependable and often leaked.
About half of the FAA Service Difficulty Reports on carburetors concern float malfunctions. For example: “THE ENGINE FAILED TO RUN MORE THAN ONE MINUTE…. THE LEFT PONTOON WAS FOUND LOOSE IN THE CARBURETOR BOWL”. AND here: “A PIN HOLE PERMITTED FUEL TO SEEP INTO THE FLOAT…… CAUSING AN EMERGENCY LANDING”.
Leaking and failing are caused by the difficulties encountered in hand soldering the seams in brass floats. In a hot submergence test, bubbles can be seen coming out of a defective float. If air can get OUT… fuel can get IN, and if fuel gets IN, the float will sink.
In 2005 the Marvel-Schebler solid epoxy float was invented. It won’t leak, the epoxy won’t absorb fuel, and, there are no soldered joints, so it won’t fall apart. Major engine manufactures, Lycoming and Continental quickly specified the solid float for use in all Marvel Schebler "MA" and "HA" type aviation carburetors.
A hole in an epoxy float makes no difference. Here’s one being drilled, then floated. Even this float with multiple holes floats reliably.
A hollow float with a hole through it readily sinks. Epoxy floats are strong, reliable and tough. When epoxy floats are subjected to minus a 50 degree cold chamber, its so cold you’d expect it to shatter when hit.
In another test a brass float and an epoxy float were heated in an oven. The brass float fell apart, while the epoxy float remains intact.
In harsh environment tests, epoxy floats were immersed in carburetor stripper for days without damage, even though some had been cut open to expose their interiors.
Many thousands of solid epoxy floats have gone into service in overhauled and new production OEM carburetors. None have leaked, fallen apart, or absorbed fuel. These advantages effectively render hollow brass floats obsolete for aviation use.
No matter who makes hollow floats… or even what they’re made of, the problem is that hollow floats are, well… they’re hollow. And hollow things can sink… whether or not they are PMA approved.
Marvel-Schebler solid epoxy floats can’t leak and won’t sink… and soldered joints that don’t exist, can’t fail.
Marvel-Schebler is the original equipment carburetor manufacturer that has supplied genuine OEM carburetors for over 70 years to Teledyne Continental Motors, Lycoming Engines, Franklin Engines, Engine Components, Superior Engines, Cessna Aircraft, and Robinson Helicopters.
Taking chances is never a good idea when lives are on the line. Choose the 21st century solution; the Solid Epoxy Carburetor Float by Marvel-Schebler.