Replacing Wing Fuel Drains

Here's what I did on my 1946 C-120:

We didn't even consider trying to unscrew it. Since I had new replacement parts, we simply drilled the whole center out of the stupid thing and used a wooden dowel to carefully spin the carcass out.

No heat. No damage. New ones went in just fine. We used a hand drill to avoid sparks and heat.

Just my .02
 
Here's what I did on my 1946 C-120:

We didn't even consider trying to unscrew it. Since I had new replacement parts, we simply drilled the whole center out of the stupid thing and used a wooden dowel to carefully spin the carcass out.

No heat. No damage. New ones went in just fine. We used a hand drill to avoid sparks and heat.

Just my .02

Interesting idea, but I do worry about getting debris in the tank that way.
 
Interesting idea, but I do worry about getting debris in the tank that way.

Another advantage of working on the drain is that it is near the lowest part if the tank. Most of the chips fell straight down to the ground and the rest were flushed out with some solvent and air...
 
How many have you done?
This is typical of a 70 year old tank fitting, I've found they usually come right out. just don't bang on them, that will place more stress on the tank than a steady pull.

Drilling it out is the proper way to remove it, if my mechanic tried to use a breaker bar I fire him.
 
Drilling it out is the proper way to remove it, if my mechanic tried to use a breaker bar I fire him.
IOWs you start drilling prior to removing it normally.
 
What does drilling it out gain? It still must be removed by turning.
By removing most of the metal until only the threads exist, there is almost no resistance to twisting out the remaining threaded metal with an easyout or a simple tapered wooden dowel. The twisting force required to turn out the super thin metal threads is very low and will not damage the tank, like applying lots of torque would.
 
By removing most of the metal until only the threads exist, there is almost no resistance to twisting out the remaining threaded metal with an easyout or a simple tapered wooden dowel. The twisting force required to turn out the super thin metal threads is very low and will not damage the tank, like applying lots of torque would.

I've seen that done once on a cessna when the tank screws got buggered up, if you are not careful the outcome is costly.
 
By removing most of the metal until only the threads exist, there is almost no resistance to twisting out the remaining threaded metal with an easyout or a simple tapered wooden dowel. The twisting force required to turn out the super thin metal threads is very low and will not damage the tank, like applying lots of torque would.
The chance of a novice doing that successfully is the same as an ice cube remaining in hell for a week.
First ..... we are not talking about a common bolt, this is a valve with a rotating center, and lots of junk attached.
You must cut away all the external parts of the valve and punch the center up into the tank, then you can start the drilling.
Then you'll have fuel draining out into your nice new electric drill, YEP this is just where every one wants to be. :)
 
What does drilling it out gain? It still must be removed by turning.

A well centered, drilled hole will leave only the threads, which can be picked out with a pointy thing, found in most mechanics' tool box. Though, if corrosion has set in between the two, Tom's solution would be next (oversize the hole).
 
Well, I definitely would try a socket first. As I mentioned early had a friend that had his mechanic drill off the buggered screws when he was removing his fuel tank. When all was said and done the skins had to be pealed back to replace the nut plates.
 
Just put a tight fitting socket on it and take the damn thing out. And if that doesn’t work the. I suppose plan B could be considered. Why folks are arguing over whether to use plan C or D is baffling me at the moment.
 
Finally got around to it this weekend. They both came out super easy, threads in the tank were clean and undamaged. I ended up having a CAV-160 on one side and a CAV-170 on the other. Loctite 592 worked great.
fuel drain.PNG
 
Torch and a fuel tank. How much insurance you have upon that plane, no matter they probably have a idiot exemption. When they weld them they take great precautions to remove all flamable conditions,
 
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