Friday, January 29, 2010

Urgent Prop Inspection

Isabella - Galapagos

The short story is we are not leaving tomorrow as planned. When we cleaned the bottom and prop this week in prep for departure I noticed that one of the blades on our Brunton Autoprop had a bit of play in the attachment to the hub. We contacted the supplier and finally got through to the engineers in England today. They don't know what might be wrong, but suspect it may be one of the bearings and suggested we pull the prop and inspect the bearings before heading off on a 2000+ mile at 11:00 we decided it was time for some quick engineering.

We had to build a prop puller as we don't have one onboard. Luckily the autoprop makes this fairly easy and the engineer gave me a hint. There is a zinc that is attached to the back end of the hub that acts as a cover for the propeller nut. This means you can use those threaded holes to pull the propeller off the tapered shaft. Some quick drawings and Dave's translations at the welder and we were on our way with a 1/2" steel plate with 3 holes for the zinc bolts and then a nut welded in the middle to allow a center jacking screw to pull the prop off. We got the screws and nuts to the welder after lunch and headed back to the boat to take the nut off the prop.

Bill and I struggled for a while, needing more leverage so Dave again came to the rescue with a socket and breaker bar which we could fit inside our emergency tiller to create a 6' lever arm. This made fairly quick work of the nut, but was a lot of work to swim a 6' wrench through the water. At 4:30 I headed back into town to pick up the welded parts (look rustic but should work fine) and 3 longer screws from Lincoln (he even has metric bolts in stock...amazing). Hopefully the prop will come off without too much more work and then we can get to tearing it down and inspecting the bearings.

This may all be unnecessary, but better safe than sorry. If there are bigger problems with the prop we can always put our spare fixed pitch propeller on and get parts down the road. More news and hopefully some pictures in the near future.

No comments: