We are about to do a repair on our flexing rudder post. The post was probably repaired before, and we want to do it right so we never have to do it again. Are there any tips or recommendations anyone has? Also, are there any material limitations? We are working with a guy from our yacht club who has been doing fiberglass stuff for years, and said we might be able to reinforce with some carbon, if that is class legal. I can post some pics shortly.
Thanks!
Jason Hyerstay
Viper 640 #42 Mojito
Lake Champlain Yacht Club
Shelburne, Vermont
Sounds like you already have a plan--but if you're not committed, I'd suggest looking at the rudder towers Ben Steinberg is making from a mold taken from the new Rondar design. Stronger and easier to get inside than the old stump.
http://forum.viper640.org/index.php?topic=511.msg4117#msg4117
I'd second that. Just before Charleston this year we installed the new design rudder post on our old Bennett boat. The rudder post came from the Mark III mold that Ben made. Solid and bomb-proof. I have lots of photos from the installation process if you go that route. It's about a half day job in total.
Oh, and Jason, no carbon. That would not be class legal. With the geometery of the new rudder post, glass is plenty strong.
I wasn't there for it, but my co-owner and some friends started the first round of the repair, grinding down the old fiberglass and checking out what was up with the bottom rudder bolts. They were disappointed to find that of the bottom rudder bolts, only one went thru the backing plate. Funny enough, that was the one bolt that held this season, and didn't just spin or fall out.
We are looking seriously at getting the upgraded post, but our fiberglass expert still thinks he can layer enough to make our existing post almost as strong.
Thanks for the help so far, everyone! I'm looking forward to getting this weak point fixed so we can be ready for springtime, and hopefully Charleston!
Cheers,
jason
There is a good chance that by making the smaller rudder post as strong as the new design, will cause it to be overly heavy. There is also a good chance that it will need fixing again relatively soon. Go with the new post.
Quote from: Dave Nickerson on October 16, 2010, 05:33:23 PM
Oh, and Jason, no carbon. That would not be class legal. With the geometery of the new rudder post, glass is plenty strong.
Oh I dunno. If they are fixing and bulking up the existing stump and it weighs as much as the existing rudder stump, surely that is okay?
Quote from: Justin Scott on November 05, 2010, 05:48:33 AM
Quote from: Dave Nickerson on October 16, 2010, 05:33:23 PM
Oh, and Jason, no carbon. That would not be class legal. With the geometery of the new rudder post, glass is plenty strong.
Oh I dunno. If they are fixing and bulking up the existing stump and it weighs as much as the existing rudder stump, surely that is okay?
Dave,
I can see where you can come to that conclusion (Rule 1.2). AFAIK, there's no carbon in any rudder posts, but my boat (#50) does have carbon bulkhead reinforcements added by Performance Boats post build, to address some early perceived structural issues. I know that the PB keels also have carbon in them. A flat out "no carbon" interpretation may be problematic.
Carbon in repairs might be something for the full Tech Committee to issue an interpretation on. I think Justin makes a good point about the weight. I tend to agree that it probably isn't necessary though, but I'm not an expert in laminates.
Jason, I wouldn't do anything with carbon until you have an official answer from the TC.
We finished the repair, fiberglass only. We ground down next to the rudder post and around the back, rebuilt the fiberglass in that area, installed an access port in front of the rudder post and a small one thru the top. We put in new thick backing plates, painted, and remounted everything. It is super-solid right now, and much stronger than before. With the extensive experience of the guy guiding us, I think it will be a long-term fix. I'll try to get some photos up soon.
Thanks for all the advice,
jason
Trying to post some photos, but it keeps failing.
Trying again...
Looks great!
Ditto