J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Prop Strut Ridiculousness

So after more hours than I care to remember stripping, fairing and sanding the bottom in preparation for new barrier coast and baltoplate, I've found something odd. As I was sanding away the old bottom paint from around the prop strut, I found a few cracks peeking through. When I pried at them with my chisel, brittle, almost ceramic like filler kept prying away until I had unearthed a "moat" all the way around where the prop strut meets the hull!



Like WTF mate? What would account for this? So strange! I'm going on the assumption that, as it is center-line, I'm dealing with just glass here. My question is, can I just fill this in with thickened epoxy and go upon my merry way or should I pair it back and do new fiberglass all the way to the edges of the strut?

Just pulled my strut out of the boat. Had bent it and the shaft lastt season. I do not have the moat around mine though it sits in a pocket similar to yours. The boat is solid glass in the area of the strut. My opinion is you should be fine just filling in with some 403 and then fairing with 407 or 410

For reference, on the inside of the boat, the two front strut bolts are on the cabin side of a bulkhead that runs almost dead center across the strut. You have to access the two back bolts from the cockpit.

The four bolts are each backed by a pan washer. When I looked at that I decided to beef it up. In the engine compartment, I built a 5/8" thick dam wider and longer than the strut and filled it with a 403 mixture. Then I put a1/4" ss plate across the top of that. My two front strut bolts run thru that ( probably an over kill)

better overbuilt than underbuilt. Filled it today and will fair it tomorrow. Doing the bottom is just grueling, has led to so many other jobs!

Unfortunately on mine the nuts were buried in the glass inside the hull. I ground them out and put in longer bolts so I could back them up. I also glassed over the strut base on the outside but that probably wasn't necessary.

Hey Russ, my strut seems to be ok, but the mechanic can't get the prop off the tranny, and needs to replace it, as they've already bent it. Did you get a new shaft, and where? Do you have specs? Length? Mine is a 3/4 inch, but thats all I have...and the boat is in Virgin Gorda. Looks as though I will need a new prop, shaft,seals on the tranny,cutlass bearing... I am trying to coordinate so all the parts are sent to me in Miami, and then I can take them down...

I did not replace shaft or strut. My shaft is 1 inch. I don't have specs and the boat is now in the water. My shaft was bent .100". Strut was bent about 5 degrees. Took shaft and strut out - had both straightened. In private message I sent you the number and name of a company in Mich that makes prop shafts - Marine Machining

If you need some guidance on how to get the shaft off, call me 734-341-8274. It took us two days and a special built shaft pusher to get ours off. No damage to boat, engine, shaft, etc.

Thank you Russ...I will call you. Headed for VG on Thursday... and need all the help I can get!

HI
What process did you use to straighten the strut? Any tips? I bent mine last week.
Thanks

Support shaft between centers, mark every 6"-8". Rotate shaft; with a dial indicator (.0005 or .001) accuracy measure run out at each 6 - 8" increment. mark on shaft the run out and also mark the high spot on the shaft. Put shaft in an arbor press, supported on each end in a Vee block. Bump the shaft at the high spots. Repeat until you are happy with the straightness. Mine is +-.010 which I considered "good enough". Time an patience - good luck

Sorry, read that wrong. Strut was straightened in an arbor press. I have a 1" shaft - we put a 1" bar in the strut (left the cutlass bearing in). Used the long bar to align with screw holes in strut as well as to measure left to right. We had stress cracks in our strut. Had the stress cracks ground and then brazed
When done and shaft is back in boat - realign the engine.
Separate the shaft coupling from the engine coupling. Use feeler gauge to measure clearance all around. use front leveling screws to adjust up and down alignment (per local Yanmar repair company)