Rudder repair or replace?

Please see the post RE new 7.9 masts

Moderators: Tim Bosma, Tom Elsen

Marionete
Posts: 64
Joined: Wed Aug 01, 2007 8:42 pm

Re: Rudder repair or replace?

Post by Marionete »

Dave;

You have a great deal more experience in this area than most amateurs on this board, including me - even though I have been making minor epoxy repairs over the last 30 years. My question(s) may seem stupid to you, but they are important to me. I am not embarrased to say "I don't know". If you don't want to answer, then I understand. Perhaps I am simply "overthinking" it.

I have an idea how to lay up the fabric and was simply asking if - in your opinion - the bond and strength of the carbon fiber tape would be better inbeween layers rather than on top. I don't know about aircraft construction, but I appreciate you adding the extra comments sharing your peripheral knowledge of similar applications of carbon fiber elsewhere in the universe.

Right now, I am only focused on a 25 year old rudder that has been repaired once before and has a wet foam core.

It was a simple enough question - I was only looking for a simple answer.

When I build my first aircraft, I may pose a few more to the S2 7.9 information warehouse of carbon fiber knowledge. (not)


:oops:
Runaway
1982 #23
dave
Posts: 727
Joined: Fri Jan 02, 2004 10:39 pm
Location: Little Rock

Re: Rudder repair or replace?

Post by dave »

Marionete, no offense was intended. You didn't ask a question, there was no question mark, and along with the quoted phrasing two paragraphs down it sounded like a statement to me.

"What I was attempting to resolve was this: bonding the carbon fiber between two layers of cloth would provide adhesion to two surfaces that will absorb and transfer load more uniformly than just one, therefore be a stronger assembly instead of simply using epoxy to make it the outermost layer before applying fairing compound, barrier coat, etc."

The way it was worded didn't sound like a question to me, hence my response. You said "that WILL absorb and transfer load more uniformly", not "may/might possibly absorb ..........". Also, if you had put "Would" before "bonding the carbon fiber", I would have known that it was a question [even without a question mark] and my reply would have reflected that.

Sorry for the confusion on my part though! :wink:
Marionete
Posts: 64
Joined: Wed Aug 01, 2007 8:42 pm

Re: Rudder repair or replace?

Post by Marionete »

Dave;

The real benefit of being able to use these boards is that 10 years ago, we wouldn't have been able to even discuss the finer points of many such issues. Had you not brought up the use of carbon fiber to enhance the design flaws in the head/blade section, I would probably have just glassed the whole thing together with 1708 - and been completely satisfied for the time being.

Now we'll use that cloth without the mat and add carbon thanks to you. Pretty cool. Will shoot you some before / after photos of the rebuild when its's done if you like.

I asked alot of questions because rebuilding a rudder is a bit different from all the other core / mast step and transom repairs tackled to date.
In addition to the glass/carbon issues, I have to laminate additional foam to reshape the warped head section, then taper it to the foil. These other finer points of reassembly crop into the picture due to the time being killed while waiting for the core to dry out. I intend to add a stainless tube as a guide for the pivot bolt to replace the copper pipe that has been removed.

As you may well imagine, I don't want to do it again - at least anytime soon.

Thanks again for your thoughtful insight and observations!
Runaway
1982 #23
dave
Posts: 727
Joined: Fri Jan 02, 2004 10:39 pm
Location: Little Rock

Re: Rudder repair or replace?

Post by dave »

No problem.

In case some of you still haven't figured it out, I don't and never will have a "PC filter"! :roll: I despise beating around the bush when life is so much simpler just saying what one believes and/or what's on one's mind. From time to time I inadvertently step on some toes, but that's not my intent. If it was, you'd KNOW IT!!!!! :shock: 8) :wink:

I have only three reasons for posting on a few forums: learning something new about things that I enjoy doing, helping others to do the same and at the same time [hopefully] keeping them from having to go through the time and grief that it took me to learn what I know about things that I enjoy doing, and.............................. enjoyment at doing the first two things!!!! :wink:
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