GB 32 Hull Thickness - 1974

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GB 32 Hull Thickness - 1974

Postby r1g2w3 » Thu Apr 12, 2018 6:47 pm

Does anyone know the hull thickness of a GB 32 - 1974? I'm picking up a SimRad Forward Scan transducer tomorrow. They come in normal and extra long. I'll be calling SimRad in the morning to confirm what the compatible thicknesses are for each.

Thanks

Grant
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Re: GB 32 Hull Thickness - 1974

Postby Bob Lowe » Thu Apr 12, 2018 8:47 pm

Get an extra long. You won't be sorry. :)
Good luck,
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Re: GB 32 Hull Thickness - 1974

Postby r1g2w3 » Fri Apr 13, 2018 8:44 pm

Found out that the normal one is good up to 1" hull thickness and 12 degrees deadrise. Might be OK?

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Re: GB 32 Hull Thickness - 1974

Postby Bob Lowe » Sat Apr 14, 2018 10:51 am

Don't forget fairing blocks and irregularities in the hull. You gain nothing with a shorter stem. Having experienced problems with the shorter stem and none with the longer stem, I still suggest the longer stem. Your choice. :)
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Re: GB 32 Hull Thickness - 1974

Postby r1g2w3 » Mon Apr 16, 2018 10:41 pm

What sealant should I use?

Sikaflex 291, 3M 5200, or?

Thanks Again.

Grant
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Re: GB 32 Hull Thickness - 1974

Postby Bob Lowe » Tue Apr 17, 2018 5:14 am

I'd stick with Sikaflex. 5200 is more of a construction adhesive.
Good luck,

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Re: GB 32 Hull Thickness - 1974

Postby oldersalt » Wed Apr 18, 2018 10:28 am

On my 1990 GB 32 (fiberglass, of course), I just had to replace a transducer. Hull midships, starboard side of engine and pretty close to centerline, is solid glass, about 3/4" thick. Right around 20 degrees deadrise, so a fairing block on the inside and on the outside is necessary. I agree with Bob...get the longer one. Can't hurt; might help.
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Re: GB 32 Hull Thickness - 1974

Postby r1g2w3 » Wed Apr 18, 2018 9:19 pm

Thanks
I measured 17 degrees today in just about the same spot. Drawing it out and using Simrad's specs for slicing the included plastic fairing block to minimum thickness I end up with about 1/2" to spare - on paper.
Will report back next week after the installation.

Grant
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Re: GB 32 Hull Thickness - 1974

Postby r1g2w3 » Mon Apr 30, 2018 10:22 pm

Installed with 1/2" to spare. Moved back a bit. About even with the forward end of the port fuel tank. 23" from c/l of shaft, left of the stringer. 15 degrees, and the hull was only 1/2" thick there. Used a carpenters laser level to be sure the forward scan beam would miss the low point in the hull about 6' forward. Now I can see rocks and shallows before we get there.

Thanks to all for the advice and comments.

Grant
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