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Steel/aluminum Q - GII : KruDave, may be?
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Author:  Alm [ Mon Jul 12, 2010 8:23 pm ]
Post subject:  Steel/aluminum Q - GII : KruDave, may be?

Dave, or somebody else who is familiar with different versions of GII, particularly 1999 - what this another Dave is talking about in trip report?
http://omick.net/adventure/kayak%20trip%202009/The%20Kayak/The%20Kayak.htm

Corroded rivets on 6 steel hinges attached to aluminum tubes with 8 aluminum rivets each?? Aren't they slotted plates - not hinges, and black plastic - not steel, at least in the last 5 or 6 years? Not to mention that Cherrylock rivets (steel?) used by Folbot are not supposed to corrode same fast as those from hardware store.

Author:  krudave [ Mon Jul 12, 2010 11:23 pm ]
Post subject:  Re: Steel/aluminum Q - GII : KruDave, may be?

Alex,

Is this the text that concerns you?

A caveat regarding our general satisfaction with the kayak is that the frame utilizes 6 stainless steel hinges, each of which is secured with 8 aluminum rivets to the side and keel tubes. Stainless steel in contact with aluminum in a salt water environment is a setup for electrolysis and 6 weeks into the trip, the rivets securing the keel hinges began to break. Fortunately, broken rivets on the keel assembly wasn't a safety issue. When we reached Ketchikan several days later, we bought a rivet gun for $12 and a dozen #10 x 1/2" aluminum rivets. Replacing the rivets was a fairly quick job.

If the rivets securing the hinges on the side tubes had broken however, the outcome might have been serious. In fact, 2 weeks later, when we packed up the boat at the end of the trip, several of the rivet heads securing the side hinges did come off. When we returned to Oregon after the trip, I replaced all 48 hinge rivets with new rivets from Folbot, bedding each one in silicone anti-corrosion gel. It took only a couple hours and the frame is now as good as new. On future trips of longer than a month, we'll be taking the rivet gun and extra rivets along.


Two comments:

1. Yes, Stainless Steel and aluminum in contact on salt water is a corrosion concern. Over time, the aluminum will corrode. Proper installation, observed wherever SS fasteners pass through aluminum hulls, is to sleeve the fastener and use delrin washers so no direct contact occurs. This is common on aluminum hulled power vessels (and there are a lot of these).

2. The hinges are the four which are on the keel assemblies (and two more on the washboards). IIRC, Folbot had a bad set of rivets near the birthing time of this boat (circa 1998 or 1999?), which needed to be traded out.

Not sure whether the rivets are all aluminum or have a stainless steel center. Never had any rivets fail like this on my 1996 GII, heavily used on the salt.

Nowadays the washboards are aluminum, distributing the corrosion over a very wide area, so the rivets there will take forever to fail. David and Pearl really put that G II to the test. Good to have them report on the failures.

Author:  Alm [ Mon Jul 12, 2010 11:44 pm ]
Post subject:  Re: Steel/aluminum Q - GII : KruDave, may be?

Yes, this is the text - thanks. What confuses me is that he is writing about steel hinges on side and keel tubes - where GII has slotted plastic plates, not steel hinges. I don't think he meant washboards - those not riveted to the tubes. There are small metal hinges at the end of the bow and stern side tubes, but not on the keel tubes, IIRC.

Author:  henry [ Tue Jul 13, 2010 9:33 am ]
Post subject:  Re: Steel/aluminum Q - GII : KruDave, may be?

Alm wrote:
What confuses me is that he is writing about steel hinges on side and keel tubes - where GII has slotted plastic plates, not steel hinges

Look at mike's photos of Aleut assembly, and you'll see the hinges clearly. The rivets go through the plates into the tubes.

GII has the same construction - just longer tubes and more ribs.

Image

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