Help Needed - possible cross-threaded fuel cap on yacht deck

[jpcarter30]

This is proving to be a bugger of a job so I'll appeal to some of you kind-hearted souls online.- The fuel cap on my yacht has sheared or cross - threaded and is impossible to open. It has a small t-shaped plastic key which is in danger of snapping and which will be hard to replace. Does anybody know of a way in which I might be able to get it off (I'm presuming the cap and unit are plastic) or where I can get a metal t-shaped key to replace it?

 

[hlb]

Try pouring boiling water over it, for a start. Maybe some WD40 or similar. If it still wont budge, you neeed a drift, hopefully wood, or reasonably soft. Then just tap or maybe bang it round. One way or the other it will have to come off.

 

[savageseadog]

When mine jammed I took removed it from the deck, much easier to deal with.

 

[MoodySabre]

[ QUOTE ]
Try pouring boiling water over it, for a start. Maybe some WD40 or similar. If it still wont budge, you neeed a drift, hopefully wood, or reasonably soft. Then just tap or maybe bang it round. One way or the other it will have to come off.

[/ QUOTE ]

We had a boat with an aluminium cap and collar that we could not shift despite hitting a drift with a lump hammer. We asked the yard mechanic who used a drift and a little peen hammer and after some persistence he got it to unscrew. So the lesson was - the less the more (and less chance of breaking it).

 

[jpcarter30]

Pardon my ignorance but is a drift a small piece of wood?

 

[srp]

[ QUOTE ]
Pardon my ignorance but is a drift a small piece of wood?

[/ QUOTE ]
It can be anything. Usually a short length of brass bar, maybe copper, but in any case it should be softer than the component you're trying to shift. That's a bit tricky with aluminium, but if you can find a bit of pure aluminium bar (as opposed to aluminium alloy) it may well be softer than the filler cap in question. A short length of hardwood might work, but it might absorb too much of the 'shock' effect, which is what you need to move it. Try the boiling water as suggested above (in conjunction with the brute force).

 

[PuffTheMagicDragon]

You can also try using two hammers, tapping with them in unison, on opposite sides of the cap and working your way around.

 

[hlb]

The idea is, your using a chisel and hammer to shock the cap round, so hitting it as near the edge as possible, in the right direction. Trouble is, a chisel is to sharp and stronger than what your hitting and will just cut it up. So use something less strong than what your hitting. Idea being that your hitting it in a way to turn the cap.

 

[jpcarter30]

thanks - I'll get on the case.

 

[highandry]

If you are convinced the filler cap is knackered anyway and needs replacing, try this.
Drill two holes in the cap one each side of the groove or slot that you put the deck key in, not in the groove itself. Screw in a couple of good stainless self tapping screws but leave them sticking up a little like 'horns'
Lay a heavy screwdriver or bar between the screws, it will give you leverage which may turn the cap. Boiling water at the same time and careful pressure on the long bar may shift it. Then you'll need a new filler /forums/images/graemlins/grin.gif