folding prop cause vibration and stuffing box leak

[dave]

I purchased an 1981 O'Day 28 a few months ago and it came with a folding propeller. When shifing into forward, many times the propellor shaft vibrates excessively. Previous owner told me that the prop isn't unfolding all the way and to put it into reverse, rev it up, then back into forward to unfold it. This usually takes away the vibration.Stuffing box has been dripping badly. I've had it repacked with dripless, but it continues to be a problem even after the repacking and 3 more tightening jobs. Mechanic thinks the vibration, caused by the prop, is causing the stuffing to leak.I'm kind of stuck for now. Not sure what to do. Any ideas appreciated. Anyone know what the diameter and pitch are to get a new non-folding propellor? I'm considering getting a 3-bladed non-folding prop. Not sure where to look or what to get and mechanic said I need the diameter and pitch.Thank you.dave, with leaking boat :-(

 

[Bob Todd]

Sounds like you have a free-folding prop...

...that is, the blades do not mesh together at the hub. The problem you encounter is due to the fact that either by wear or debris one blade is not opening fully. However, it also could be caused by being out of balance due to damage or excessive marine growth on one of the blades.Another cause could be that the rubber bushing in the hub is worn.In any case, you need to have a specialist look at it.If you need a new prop, and you'd like another folder, I'd suggest a folder that has blades geared together at the hub.I installed a stainless steel Seahawk Slipstream folder on my Nonsuch 30 at the beginning of the season. This replaced the original Volvo folder that was on there. The prop performs every bit as good as a fixed including backing down in reverse and does not have any discernable amount of prop-walk.You might want to contact H&H Propeller (link below) and ask for Jim Blanchard. They will be able to determine proper size and pitch for your particular boat, whether fixed, feathering, or folding.Even though I have quite a bit of experience with most thing marine/mechanical, when it comes to the prop, I rely on the professionals. There are too many variables and prop failure could be catastrophic.Good luck to you.Cheers,Bob