LettersFromFlyoverCountry

Well Known Member
What do you folks use between the FAB plate and the bottom of the Silver Hawk EX. I've been. Making a gasket out of cork material but I'm wondering if there's a better option.
 
I seem to remember getting a gasket in the FWF kit for that, but I'm not absolutely sure. I would use a standard paper gasket instead of cork.
 
Ooh, I've heard really bad things about using RTV here. I think I heard it on VAF.
I didn't use anything - see no need for an extreme pressure tight seal here. (Quality of fit between machined aluminum servo body and rolled flat plate will allow near zero leakage at these pressures.) But just curious as to what could be bad about using RTV? If it extrudes into the bore, any overage would easily pass through the engine.
 
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Hey Bob, I am not to the air box stage yet, but what is the flange to the servo made of? If it is all fiber glass then your cork/rubber mix gasket material would work well if it is thick enough. If it is aluminum (stiff), then a paper gasket material would work.

Gasket material and thickness are selected based on the stiffness of the flange materials and how much the gasket would compress to ensure a seal between fasteners with a little deformation.

For my new Lycoming, (read $$$) I will be sure no dust gets in the engine. By reference, a thimble full of dust in the oil would grind up the engine in a hundred hours. See the post today about the sandblasting of the air box aluminum by ALEX for some idea of dust and sand that might get sucked in.

Good luck.
 
It's all AL, the plate for the airbox is .063, mates directly to the bottom of the servo. I'll switch to paper. The cork gets pretty well saturated with 100LL and messy. Originally, I was trying to minimize any vibration damage to the plate.
 
By reference, a thimble full of dust in the oil would grind up the engine in a hundred hours.
Good luck.

That is an interesting comment. Is it just a WAG or do you have a reference?
My Pitts, like most, flew without an air or oil filter for 25 years. I am certain it sucked more than a thimble of dust during that time. Inquiring minds want to know.

Jim Berry
RV-10