J/30 Class Association Forums J/30 Forum The Boat, Sails and Equipment Cutless Strut Moulded Recess

I am wondering if anyone has more details about the construction of the recess that the prop shaft strut is mounted to. I have water intrusion from somewhere under the interior liner aft and I suspect it might be from either the shaft log or the strut mount. I may have to cut the floor liner away from both to figure out what is going on... I just want to be prepared for what I am in for if I need to repair it.

*crickets*

I did not think the liner goes that far back??

Here's a Rhapsody picture above the strut mount taken from the port side looking aft. The original owner had the 3/4" shaft replaced by TPI with a 1" shaft and required that the strut be replaced. There are no seams around the interface, so unless you have a crack in the bottom, I doubt that is the source.



Here is a picture with the Yanmar removed so you can see the area where water can enter the liner area. What is more likely is that water is getting in the openings on either side, or entering the holes on the lip where the engine cover rests.

1. Bill ... what is that box with the tube in it that would be directly under the motor?

2. The strut mount is another engineering fault with the orginal design ... and which they tried to "help" by going to the 1" shaft. The strut is not as stable as it should be and we have had to fill and fair around it year after year, water seems to seep in a bit through the bolt holes.... Horatio, my current fiberglass guy, and original construction crew back in 1980s at the factory, has decided that the only way to solve this strut integrity problem is to epoxy the strut completely in with glass. Which he did on #526 in 2009 ... and showed no sign of problems when we pulled it in Sept. 2010. Somewhere I have photos and if I ever find them will add to post.
#505 does have a slight weeping through those bolt holes -- on a long list of to-dos on 505

Vic - I used to have a hand pump bolted on a 2 x 4 to use for oil changes. When I rebuilt the engine, I removed it. I now use one of the Pela 2000 vacuum pumps to change the oil.

Thanks guys. I am pretty confident that it is coming in at the strut. I can actually see water seeping on to the top of the liner from the liner/epoxy interface as well. The leak is fairly significant. After I run the engine it produces about 5 gallons in the bilge per day (sometimes more if it was significant journey). This continues daily for a couple of weeks and then slows considerably until I run it again. My theory is in that time my friend "brown freshwater slime" grows enough to slow the leak (swear it is slick enough to make my hull faster too :P)

How is the strut bolted on? There are no bolts showing through so are they epoxied over on the back side?

I am glad to hear that there is no interface between the hull and the mold, I was extremely worried that there would be water infusion into the core as well. Vic, I am strongly considering doing exactly that, glassing over the strut completely.

I realigned my engine the other day, I hope that helps a bit. It was not out by much but I definitely made an improvement. The leak had slowed, but idled the motor for ten minutes and turned the shaft by hand while aligning and sure enough the bilge was full the next day.

1. There are four through bolts in the strut flange which we all naturally fill over and fair. duh... so you are not going to see them unless the fairing starts to peel. Also I agree with the slime gasket theory. running hard disrupts it.

1a. Also look at your prop ... they have a tendancy to get out of balance like a tire and vibrate which goes right to the strut base.

2. Bill Re Pela ... inherited one with 526 ... taught Lisa H how to use it last Sept. just have to remember it still needs hot oil to work really well ... as we found out.

Sorry for clarity on point number 1, I was referring to the backside of the strut mold (i.e. inside the boat). I can see the heads of the bolts on the strut side; they haven't been faired over. Are they just bolted directly into the epoxy mold, or are they truly "through bolted" into the inside of the boat and the nuts epoxied over.

On Rhapsody the bolts are glassed over on the inside. Again, this was modified so your configuration may be different.