Leaky tank

Hamsi
John Anderson
Wed 14 Jun 2017 18:33
Current position      43:19.42N 42:02.26W
 
The weather the night before last gave rise to a lot of rolling around.  At one point I awoke smelling diesel. I thought that either one of the auxillary plastic diesel cans had started to leak on deck, or it was coming from the main tank underneath my bunk,  The sea state was impressively lumpy.  I did not fancy a stroll on deck in the night in these conditions.
 
I got up early when the sea state had moderated.  The good news is that the cans were fine.  I therefore emptied the contents of my cabin into the rest of the boat in order to look at the main diesel tank underneath the bunk.  Both the hatches in the stainless diesel tank were fine (good news since they leaked a few years ago), but diesel was lapping out of the edge of the tank sender (the device that measures how full it is) whenever we were flung around a bit.  There had been no smell on previous days, when the conditions had been rough.  I imagine that some seal / O ring had decayed and failed and perhaps the sender had moved a bit with all the motion. It was not overtly loose. 
 
I didn't want to take the sender out in case the lapping of small amounts of diesel became a sloshing of large amounts. It wouldn't tighten up any more that it was. 
 
I could never clean around the sender long enough for any tape of othere fixitive to do anything other than slide off the greasy diesely surface. 
 
I decided to pack the area with one of the nappies that I keep in the first aid kit in case of a large bleed, topped off with a piece of Ruth's old CLSG jumper, in the hope that this would contain the problem.  When one of the diesel tank inspection hatches leaked a few years ago the diesel found its way into the bilge via some circuitous route and I knew where it came out.  I packed that area too.
 
Morning tea was delayed until there was no longer water spraying on deck.  At that point I ventillated the boat and pumped the diesely air from bilges and felt it safe enough to light the gas stove and put the kettle on. After all this, and a few sail changes I needed a late morning nap, but the diesel smell in my cabin was too persistent and I had to snooze on Lorna's bunk.
 
The seastate gradually improved during yesterday.  I didn't think I dare take the sender out when there was any sort of sloshing going on (most of the time since we were in following seas and things were a bit rolly ). 
 
I emailed Neil to talk things over. 
 
In the evening I felt that I had to renew all the cloths that had been put in place to stop diesel spreading.  With everything out of the cabin again, it was clear that the rolling was a lot less than earlier.  We had a piece of flat rubber on board that Neil had used to make a rubber washer for a leaking hatch handle.  I got the sender undone (with only a couple smallist slops of diesel) and measured the size of its hole screwing it back in place as fast as possible. 
 
It was then time to draw out a washer shape on the rubber sheet with a one inch, five eights hole in it and cut it out.  Waited for a quiet moment and unscrewed the sender, banged on the washer (with only a little more diese lapping out) and screwed it home. 
 
Further absorbing cloths placed, and another night spent out of the bunk.  Boat again aggressively ventillated before lighting the gas for supper. 
 
Today the diesel leak had stopped and the cabin become inhabitable again.  The rough and ready rubber washer seems to be doing its stuff.  Phew.