Hobie 16 Hull creak

So I got the boat all tuned up the season, had a couple great sails, then the derecho storm June 29 deposited a large limb on my port hull and sidebar. Crunch! I found nearby and bought an oldie (1984) with solid hulls, no soft spots for parts and replaced the hull and side bar. Put it all together, tightened the tramp, and then lifted the hulls to test for stiffness. The boat seems decently stiff, but the "new" port hull creaks whenever I lift and lower it. At first I thought the creak might be the pylon, but it is definitely coming from INSIDE the hull. I talked to someone who just told me that lots of hulls creak, but I am concerned that I cannot see the cause. Does anyone have any knowledge or experience with this? Has the pylon structure possibly separated from the hull inside? Has anyone seen a hull fail for this reason? Thanks for any input.

Hmm..., no one seem to be answering your question!

I don't have strong expertise with your problem, but if it is creaking, something must be moving, even if just a little. I'd keep sailing it, and see if it stays the same or slowly gets worse. Keep asking the question of other sailors as opportunity allows in the meantime. I have seen the inside of Hobie 16 hulls. If the pylon attachment has a problem you will have to open up the hull to fix it. So if it is a minor annoyance that doesn't get worse, I'd live with it.

Yes.

Yes.

Two possible things:
1) The pylon shoe has become detached from the hull skin. You would notice a depression in the deck around the pylon fairing and possibly bulges in the hull sides directly beneath the pylon.
2) The pylon shoe is broken - the sides are still attached to the hull and the creaking you hear is the two halves rubbing against each other. This is most likely what's going on.

The solution involves major surgery - an access port needs to be cut in (behind the pylon is better structurally) and be prepared to be up to your shoulders in glass and epoxy resin as you reinforce the pylon shoe.

Unidirectional carbon fiber tows laid in an "X" pattern across the pylon shoe and along the hulls works well, but it's nasty work.

But,if it is just making some light noise and there is no visible distortion, do you think he should fix it now. or wait?

It's not going to get better by itself, and it will get worse. Maybe much, much worse.

You don't have to fix it now if you're not going to sail the boat, but you need to fix this before sailing the boat again.

One source of creaks is sidebars in corner castings. That can transmit sound and maybe ... just maybe down into the hull? We suggest beveling the ends of sidebars and lubricating them. This is a bigger issue with french made corner castings for some reason. Harder anodize maybe. But as Matt Bounds says... if it's broken fix it before sailing. Even a short distance out in the water can cause big issues if the hull fails. Not worth it.

At this point, I think you need someone else to listen to your "creak". Are you excessively worring about a very small noise, that others would hardly be concerned about? The folks that are "beaching" your boat, might have another opinion, if they actually heard the noise. (My boat creaks occationally, but I know its the sidebar/corner joints.) Get a firsthand experienced opinion from another sailor, before drawing any desperate conclusions.

Thanks for all the replies, sorry I have been out of touch for awhile. I actually have sailed the boat several times since the post and have not heard any more creaking. I will check it out again on land now and also be very attuned to it when things warm up here again in the spring. Thanks.

Keep us up to date on this story.

My theory, at this point, is that your new hull from a different boat, has now worn in to the rest of your original boat. If true, then it must have been an aluminum rubbing on aluminum noise. The posts could be slightly out of position from your old hulls, which slightly changed how all the aluminum parts fit together. Once a little wear occurred, it quieted down. Of course, theory is not necessarily fact; so stay a little weary, until the boat proves itself.

This brings up a question that I had about how stiff should the boat be. Specifically, should I be trying to shim the corner casting to hull strut joint to eliminate movement or is a little bit desirable. My boat is a late seventies H16. The frame is very rigid with the trampoline on but there is a very little bit of motion between the frame corners and hull struts.

Stiffer the platform the better if you're racing. If not, meh.

Look at the A's, they get rid of as much slop as physically possible. Flex is energy lost.

Ditto...

If racing, all slop is bad. But, it's a Hobie 16, and there's only so far you can go due to the design. It's almost impossible, even with a glued boat, not to have at least some amount of independence visible as the bows travel across the water, particularly if it's rough.

If not racing, slop is bad if it leads to further damage. You don't want the boat to be wearing itself out as parts rub together. If you see movement, it is best to try to reduce or eliminate it, so that you don't wear away material that may be difficult or impossible to repair without major work or expense.

Hope this helps.

Mike

should I be trying to Aion Kinah[/url] shim the corner casting to hull strut joint to eliminate movement or is a little bit desirable. My boat is a late seventies H16. The frame is very rigid with the trampoline on but there is a very little bit of motion between the frame corners and hull struts.