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Modifications & Equipment / Re: Repair blog: chainplate & tie rod replacement Bavaria 47 cruiser 2001
« Last post by UP on May 06 2024, 09:15 »Update #6 - FINAL
Yesterday I finished my 2001 Bavaria 47 port side chainplate and tie rod install (99% of it). I've attached images of what the end product looks like.
I decided to install the deck mount with butyl tape, as an experiment, as it is a somewhat dynamic fixture and butyl tape can stay sealed under shear loads while Sikaflex cannot (once a threshold is passed). I understand that it is a matter of decision and preference somewhat.
Also, I was faced with the issue of how tight should the tie rod be? I had no tensiometers at hand and I ended up by tuning the tension by ear - yes, I tapped on the starboard rod, listened for the pitch and tightened the port rod until a similar pitch was heard. I confirmed the results with a smartphone tuning app, which surprisingly worked well. The starboard rod was resonating around 80 Hz at the E2 pitch.
The 0.1 % still left to do is tightening the two large M30 nuts to properly form an anchor-lock for the rod. I cannot fit two wrenches in the bulkhead bracket and I'll have to find a way to jam the upper nut so I can torque the lower one.
To conclude this topic, here is what I learned in short:
Thanks!
Yesterday I finished my 2001 Bavaria 47 port side chainplate and tie rod install (99% of it). I've attached images of what the end product looks like.
I decided to install the deck mount with butyl tape, as an experiment, as it is a somewhat dynamic fixture and butyl tape can stay sealed under shear loads while Sikaflex cannot (once a threshold is passed). I understand that it is a matter of decision and preference somewhat.
Also, I was faced with the issue of how tight should the tie rod be? I had no tensiometers at hand and I ended up by tuning the tension by ear - yes, I tapped on the starboard rod, listened for the pitch and tightened the port rod until a similar pitch was heard. I confirmed the results with a smartphone tuning app, which surprisingly worked well. The starboard rod was resonating around 80 Hz at the E2 pitch.
The 0.1 % still left to do is tightening the two large M30 nuts to properly form an anchor-lock for the rod. I cannot fit two wrenches in the bulkhead bracket and I'll have to find a way to jam the upper nut so I can torque the lower one.
To conclude this topic, here is what I learned in short:
- The chainplate-tie rod is well engineered and it is not an easy task to reproduce, as the steel used is not off-the shelf 304 or 316L type;
- The rust I saw was superficial and the only pitting I saw was on the 304 steel M30 bolt: eg. rust seen on this setup is most likely not a red alert;
- The plans I received from Bavaria do not include a torque or tension rating for the tie rod. What I concluded acoustically is that the factory installed starboard tie rod resonated around 80 Hz or the E2 pitch.
- I would like to thank Bavaria customer support for digging up old plans (as shared in this thread) for a retail market customer, they could have very well said NO and I would have accepted this.
Thanks!
