Nacra 5.2 rear hull to cross bar connections

**unknown user**

Rank: Lubber

Registered: Jan 01, 2024

Last visit: Jul 17, 2009

Posts: 2
Posted: Jul 16, 2009 - 10:48 PM

Has anyone had to repair the rear hull to cross bar connections on the Nacra 5.2? I have a 1976 with horizontal crazing in the gel coat on the inside and outside of both hulls just below the cross bar. no problems on the front.

What are the strap bolts threaded into?

Would adding a bulk head inside the hull at the hull to cross bar intersection help [like the front cross bar to hull has?]

I am new to the forum and looking for advice or thoughts of any kind

Thank you
P.M.

Rank: Mate

Registered: Jan 14, 2004

Last visit: Sep 25, 2024

Posts: 866
Posted: Jul 17, 2009 - 01:24 AM

Good question James. The crazing your seeing is rather common. I would keep an eye on it but not worry to much about it. If you happen to take the rear beam off, take a bright flashlight or light bulb and put it to the hull and look through from the top in the dark. If there are issues you will more than likely see them.

The "strap" bolts or beam bolts thread into an aluminum plate, that is laid up in fiberglass. I have seen on occasion brass plates, usually on older boats. Pretty simple lay out. If you were to strip out the thread in the aluminum, or it is a victim of galvanic corrosion, you can simply tap it out to the next size bolt. You will also need to drill out the stainless steel beam strap. If you happen to have any beam bolts out make sure you apply copious amounts of marine grease when reinstalling them.

Welcome to the forum. Where are you located?

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Philip
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yurdle

Rank: Mate

Registered: Aug 22, 2007

Last visit: Jan 07, 2015

Posts: 742
Posted: Jul 17, 2009 - 02:10 AM

Just curious - what is the purpose of the marine grease? I often see references to it for hull connections.

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Rob
OKC
Pile of Nacra parts..
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P.M.

Rank: Mate

Registered: Jan 14, 2004

Last visit: Sep 25, 2024

Posts: 866
Posted: Jul 17, 2009 - 08:25 AM

It isolates the two dissimilar metals, stopping the galvanic process. You are doing the same thing when applying caulking or sealant to the rivet hole first before seating the rivet. It provides a barrier and helps isolate the rivet from the hole.

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Philip
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**unknown user**

Rank: Lubber

Registered: Jan 01, 2024

Last visit: Jul 17, 2009

Posts: 2
Posted: Jul 17, 2009 - 10:22 AM

Hello all,

Thank you MUMMP for the response, I will look at night with a light source inside.

If there is light coming through, what is the proper structural repair for this crazing and/ or cracking.

I am located in sheboygan wi.

Thanks,