transoms

Outboard designs up to 14'

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vintage
Posts: 12
Joined: Sun May 17, 2015 9:32 am

transoms

Postby vintage » Sun Jun 07, 2015 6:50 pm

Hi everyone. Just building a flying saucer and was curious if anyone doubled up their transom bottom and side frames to give the bottom and side ply wood more surface to adhere to to prevent leaks. I will glass the outside anyway but I'm most concerned about the bottom of my transom. Also should I lay glass to the inside corners of the transom? Any ideas would be appreciated thanks

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rbrandenstein
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Location: O'Fallon, MO

Re: transoms

Postby rbrandenstein » Sun Jun 07, 2015 8:02 pm

I think if you are careful, it is not needed.
It probably wouldn't hurt, but it will add some weight.
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Completed Malahini (launched 6/24/2012)
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BarnacleMike
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Re: transoms

Postby BarnacleMike » Sun Jun 07, 2015 8:45 pm

Some people have built thicker transoms than specified in the plans, but primarily for added strength in supporting the motor, and not really for leakage protection.

For my part, I'd say that putting your pieces together with liberal amounts of thickened epoxy or Gel Magic will go further toward leak protection than using thicker wood to build the parts. Your main benefit from the thicker wood will be structural strength.
-Michael

Built Utility "Perseverance" — completed Aug 2016
Currently building a Zip
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Andy Garrett
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Joined: Tue Aug 31, 2010 11:44 pm
Location: Nampa, Idaho

Re: transoms

Postby Andy Garrett » Wed Jun 10, 2015 7:20 am

I never even considered it. The design is very solid as is and has been for a long time. Try to resist the urge to over engineer unless you intend to stress the structure in ways that exceed its design intent.
Andy Garrett

Perhaps the slowest Zip build in Glen-L history...

John K
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Joined: Thu May 18, 2006 5:19 am
Location: AL

Re: transoms

Postby John K » Wed Jun 10, 2015 11:12 am

I added 3 transom braces at the bottom and 1 at each corner at the top. The top of the transom takes the most stress when you are towing or when the boat bounces in rough water.

I was never concerned about leaks as long as the transom was strong.

polarisman14
Posts: 223
Joined: Tue Oct 04, 2011 7:04 am

Re: transoms

Postby polarisman14 » Thu Jun 11, 2015 9:29 am

I am planning on running a 35hp chrysler short shaft on my flying saucer and augmented the plans by laying a piece of 3/4" marine ply within the 4/4 outer framing for the motorboard (the whole width, not just a small square as the plans suggest). I also made 2 additional transom knees the same size as the one for the keel, to run on the outer battens (which I increased from 2 to 4 total). I don't doubt the initial design's ability to hold 35hp of force (versus the 25hp max suggested), but having it sit on a trailer with the weight of the engine sitting over the transom for long periods of time probably won't be good for it. I am even considering pulling the engine during winter storage as that isn't too complicated and will take a LOT of the stress off of the transom.


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