The place for technical discussions about GA and flying.
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User avatar
By Charles Hunt
Had a stuck fuel tank drain yesterday that wouldn't reseal no matter how many times I tried.

Replacement drain fitting on order.

Original fitting had been in there 20 years and there seemed to be some hardened grey thread compound on there.

What should I use during re-assembly?

(Irv has already linked me to chewing-gum manufacturers.)
User avatar
By romille
avtur3 wrote:
romille wrote:I think there is a sealant called Permatex that can be used but whatever you do don't use PTFE tape.

Genuine question, why not PTFE?

I believe that fuel can cause it to degrade it can then break away and enter the fuel system. I have seen evidence of it going soft and sticky on fuel lines.
By PatT
Pure PTFE thread seal tape will NOT be affected by aviation fuel (or any chemical you are likely to come across.)
However if not carefully applied bits can be chewed off during assembly and block an unfiltered jet.

G-PTFE :wink:
User avatar
By jaycee58
I don't want to be overly pessimistic but surely a fuel tank drain shouldn't be that difficult to seal? I would examine the the thread in the tank drain very carefully for a very small crack axially along the thread or emanating radially from the drain.