Locking Fuel Cap?

[CanalRetentive]

Is it possible to get a locking fuel cap for this? Threads on the tank are external, my first thought is no without changing it somehow?

 

 

[Alan de Enfield]

 

 

Yes, a simple bit of welding :

 

 

 

 

 

[CanalRetentive]

11 minutes ago, Alan de Enfield said:

 

 

Yes, a simple bit of welding :

 

 

 

 

 

 

Not too bad an idea actually, sometimes simple is best!

[Machpoint005]

My approach for the last 14 years has been to use a big wrench to tighten the cap. It's then impossible to get off without a similar tool. 

 

 

[David Mack]

I have also seen that type of filler with a hole drilled horizontally through the cap and pipe and a long shackle padlock through the whole thing. But I would worry that might be a route for rainwater to get into the tank.

[blackrose]

Yes, why would you drill holes in your fuel cap!

[BEngo]

Since I can only just get a 1/4 in square dipstick down the filler hole to the bottom of the tank, which is below water anyway, I figure that no one is going to siphon it out and pumping will be rather slow too.

N

[Jen-in-Wellies]

Sent my method of locking a similar cap by PM to @CanalRetentive, rather than telling the whole world!

[Tony Brooks]

Drill and tap one side of the cap and plain drill a corresponding hole in the pipe. Fit  a domes  security screw into the hole and rain can't get in. Totally DIY if you can drill and tap and no welding. Get a security screw with a pin in the middle plus two suitable bits (one as a spare).