Sick as a parrot!

[Iain_S]

Update on this :

The new mushrooms (from Midland Chandlers) have been fitted. The thread was the same (¹/₂" BSW) as on the old ones, so the old bases could be used, and didn't have to be removed from the boat. We also salvaged the old nuts to use as locknuts.

 

One vent had the base drilled out as per OldGoat's post.

Inspection of the new vents revealed that the engineering was a bit agricultural : the nuts were made from rough cast hex bar; had off centre holes, and there was about a millimetre difference measured across the flats at right angles.The threaded rod was 12mm diameter, so that the thread wasn't fully formed. The thread was, however, locked into the dome with epoxy (I think) and centre punched around the hole. It was solid, anyway.

 

The next vent had lock nuts tightened together and the top was turned with some force. The 0.7mm missing from the thread on the rod was enough to allow the original base thread to strip before anything else came adrift, leavng the vent as per the first one, so we didn't bother drilling out any of the other bases.

 

If there IS a next time, we'll use plant pot bases, or aluminium dog dishes or something

 

Iain