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Normancruiser20
Norway
4 Posts |
 Posted - 27 Jan 2013 : 17:08:54
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Hi.
i am a new owner of a 20feet Norman Daycruiser.
I bought it without an outboarder. But after reading a several
threads here i have become a litt concernt about the transom.
The former owner of the boat have glued a big stainless steel plate on the "back" of the boat and used som bolt and washer to fix it.
The major concern is, if i will use the boat under coastal conditions
with a new 60Hp Yamaha outboarder will this construction hold the 114kg safe on place?
I dont know how to add pictures 
Cheers from Norway |
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Normancruiser20
Norway
4 Posts |
Posted - 27 Jan 2013 : 18:38:30
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Here is the picture of the plate. Any advise? I dont want to loose my
new motor to the sea :)
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mikeb
90 Posts |
Posted - 27 Jan 2013 : 20:07:43
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Mine has a similar plate, and also a 60hp outboard, although yours looks like thicker metal. My theory is that the main purpose of the plate is to spread the clamping loads of the outboard, any weight and torsional strengthening from it ought to be minimal. I don't think the presence of the plate itself proves that the transom is rotten.
If your transom is rotten enough it could still fail even, with a plate that size, when you consider the forces involved (weight and power).
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Normancruiser20
Norway
4 Posts |
Posted - 27 Jan 2013 : 21:58:23
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I hope that cracks will be visible before its fall apart.
It seems to be sturdy enough but you never know.
Maybe i should drill a hole or cut away the first layer of fibreglass as seen on the third picture above the bilgepump, to see if it is rotten or not.
On the first picture you can see 3 screws from a fishfinder like on your picture mikeb. How can i seal it beneath the waterline? Is it enough with some kind of silicone or may i have to use epoxy?
Its my first boat, so i have a lot of questions 
Thanks for any help, i appreciate it! |
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newcommer
United Kingdom
63 Posts |
Posted - 28 Jan 2013 : 10:49:18
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Hi
The stainless steel plate on my 1st boat was used to defeat the outboard thieves. My fish finder is attached to the sensor via a steel pipe the pipe is fixed to the stern with some pipe hanger brackets which are nut and bolted above the water line this enables the senor to moved out of the way when recovery or towing i hope this helps.
Pete
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cliveshep
Thailand
1324 Posts |
Posted - 28 Jan 2013 : 13:43:12
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The motor well and deck moulding on the Normans join at the external angle of the well and transom and are sometimes indifferently bonded together. The joint is often covered by a small aluminium angle pop riveted on. It follows therefore that one major design weakness of Norman boats is going to be the transom as under way the joint is constantly splashed and water will seep in. So - they rot!
60hp will rip a rotten transom clean off the boat as all you have to stop it is the 6 ounce layup inside and the possible 8 ounce on the outside and pulp in between.
So I suggest that unless you can find a marine surveyor with a moisture meter who can give you some indicative hull moisture readings all over the transom area, you should drill three 8-10mm holes down through the top of the transom just through the grp, space them centre and either side of the well, and have a probe with a steel probe such as a knitting needle or long thin screwdriver and evaluate how sound your transom actually is.
The holes can easily be repaired with epoxy putty if you find no rot but if you find rot you would be best to open up the top of the transom and clear all the rot out from the top before filling the void up with resin plus something, possible some re-bar,that transmits the loads out to either side of the motor well because the sides of the well do offer some lateral load resistance.
Once the void is full you can simply sand the top off and spray paint it.
The cost of boating is insignificant compared to costs of a young wife and two teenage kids! |
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mikeb
90 Posts |
Posted - 28 Jan 2013 : 15:07:57
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quote:
Originally posted by cliveshep
filling the void up with resin plus something, possible some re-bar,that transmits the loads out to either side of the motor well because the sides of the well do offer some lateral load resistance.
Once the void is full you can simply sand the top off and spray paint it.
I do wonder about filling with something solid like resin though. As standard the transom will have a bit of flex/give. If you replace the balsa with a solid setting resin it effectively makes the transom one solid piece rather than a sandwich. Hence it being stiffer/more rigid than original, and I worry this might increase the forces/shock loadings where the transom is bonded to the hull sides and longitudinal supports.
Am I just over analysing or being paranoid? |
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Normancruiser20
Norway
4 Posts |
Posted - 31 Jan 2013 : 16:39:15
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I took contact with the former owner of the boat and he said he used some oak beams to build up the transom.
This sounds solid for me and i will test it in the coming boatseason.
If any damage will occur i will take it from that point.
Now i have ordered the motor and can not wait to get the boat to water.
Thanks for your replies! |
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Topic |
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Transom problem
