How to measure for a level floor in V-hull aluminum boat

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seanymph85

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I recently purchased a 1985 Sea Nymph 14R Big Water V-hull aluminum boat. It had some decking/flooring in it but most was rotted out underneath. There is some aluminum angle fastened with rivets to the factory bench seats. However I do not believe they are level. I am trying to figure out how to install the angle supports on the outside edges of the decking so the floor will set level or at least close to it when the decking i.e. plywood is installed on top of any floor supports. There are 3 bench seats and for now I just want to install or re-install floor decking that only comes up to around the bottom of the bench seats in the middle two sections. I will tackle the bow and transom areas at a later time. I thought I could put a straight edge across the seats in question and measure downward and locate all the angle bracket supports at the same distance. This does not work as the bench are not all at quite the same height as the others, or at least do not appear to be when measuring down to the top of the seats if using the top rail as a reference point.

In any case I need to know what to do when measuring to insure the deck supports and or angle locations are installed that the end result will be a fairly level floor. I can take pictures with measurements to better illustrate what I am trying to accomplish and show the style of the boat hull as well. I am reasonably capable with carpentry but there are allot of variables on this and with the floor/hull of the boat sloping toward the bow I am uncertain if there is a simple starting point for measuring for floor supports whether they are aluminum angle on the outside edges or sealed wood stringers of either a CCA treated wood or otherwise sealed with some type of epoxy sealant. Any tips on where to start when measuring for supports so the end result will be a fairly level floor are appreciated.
 
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jigngrub

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Re: How to measure for a level floor in V-hull aluminum boat

Measure down from the top of your gunwales.
 

64osby

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Re: How to measure for a level floor in V-hull aluminum boat

Playing devils advocate - What is the weight capacity of the boat? Is the extra weight worth having a floor?

I had one 14 with 575lb plus a 10hp, my Lone Star is 765lbs including the motor.

2 big guys, gas, gear, cooler(s) and up to a 25hp (spec) could easily be 700lbs.

A few pics would also be great to see of your Tinny.
 

seanymph85

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Re: How to measure for a level floor in V-hull aluminum boat

Measure down from the top of your gunwales.

Thanks for the info! Please forgive my apparent ignorance but I assume the guwales is the aluminum extruded trim going around the top outside edges of the sides on the boat. Is that correct? If so The widest point across the boat is about 62" so I imagine I will need to locate a piece of heavy angle or some straight edge long enough to measure down to angle supports across the gunwales. Though again if my understanding of this is correct I like the idea and will try it ASAP after I locate some material to use for a straight edge across the boat.


Do not let what you can't do interfere with what you can do.
John Wooden
 

jbcurt00

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Re: How to measure for a level floor in V-hull aluminum boat

Where do you plan to use the boat? Small lakes? Michigan rivers? Great Lake?

As you add weight, the original flotation foam is not likely to fully float the boat if it becomes swamped. Raising the height of the surface where you stand & move about in the boat can also make it more prone to tipping.

^^^ Just more to consider as you proceed.
 

jc55

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Re: How to measure for a level floor in V-hull aluminum boat

Straight edge, string with a rock tied on either end...;)
 

seanymph85

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Re: How to measure for a level floor in V-hull aluminum boat

Floor Area2B.JPGFloor Area1.JPGBigWater2.JPGBigWater1.JPGFloorArea2.JPG
Playing devils advocate - What is the weight capacity of the boat? Is the extra weight worth having a floor?

I had one 14 with 575lb plus a 10hp, my Lone Star is 765lbs including the motor.

2 big guys, gas, gear, cooler(s) and up to a 25hp (spec) could easily be 700lbs.

A few pics would also be great to see of your Tinny.


Hope I am doing this reply right. The info tag on the boat says 830 lbs. total with boat, motor, people and gear. It specifies a rating of 25hp which is what it has on it now. A mercury 25 hp/electric or pull start. There will not ever be more than 3 adults and most of the time not more than two. If a floor is put back in it will only be a very shallow floor to provide a level surface to stand on. As it was the brackets between the rear bench and the next bench forward were at about 2 3/4" on one side and maybe 4" on the other side on the next bench. Hopefully that make sense. I wouldn't need real heavy wood supports and the plywood would only be around 2 1/2' x 4' in that section. I don't believe it would take much wood framing supports below for adequate support. I want to make it removeable for cleaning from time to time. I will not be putting seats up high on a deck which as was mentioned can further make things top heavy etc.
The area where the gas can and battery is had a low floor to and is located beteen the 2nd forward bench seat and the third seat. I expect someone had it there to put more of the weight toward the front of the boat.
 
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seanymph85

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Re: How to measure for a level floor in V-hull aluminum boat

Where do you plan to use the boat? Small lakes? Michigan rivers? Great Lake?

As you add weight, the original flotation foam is not likely to fully float the boat if it becomes swamped. Raising the height of the surface where you stand & move about in the boat can also make it more prone to tipping.

^^^ Just more to consider as you proceed.



Wouldn't mind having something for Lake Michigan but no this would never be used on the Great Lakes. I wouldn't be confident even without a floor it would be adequate in size etc. to use there on open water. I may use it eventually on the St. Joseph River in the Niles or Berrien Springs area with hopes of salmon or steelhead fishing but not on any really large lakes like Michigan which is the closest of the big lakes to where I am at. Yea just small inland lakes mostly and perhaps as mentioned the St. Joseph River or other smaller rivers. I will be adding a bilge pump too but more in case of a leak or something like that. If even a shallow floor would turn out to be a problem I will just put some floor mats or something else similar.
 
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seanymph85

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Re: How to measure for a level floor in V-hull aluminum boat

Straight edge, string with a rock tied on either end...;)

Excellent easy to understand idea that will work with the gunwales suggestion. Be like using a plumb-bob.

THANKS!

The successful man will profit from his mistakes and try again a different way.
Dale Carnegie
 

64osby

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Re: How to measure for a level floor in V-hull aluminum boat

I would look at the edges of the floor resting on the top of the outer edges of the ribs, use c or u alum channel to provide support on the ribs spaced 12 to 16" at the most with 1/2" ply.

Did this originally come with a factory floor?
 

seanymph85

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No factory floor to my knowledge, just had some flooring/decking between back and middle and middle and front bench.
 

83mulligan

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cut your floor to the shape you want at the height you want and pour flotation foam under it. Then you don't have to worry about supporting the floor at all and you will have some foam for safety. just form in the drainage channels and use butchers paper on the bottom of your deck and you will have a flat stable surface. Use some angle for a couple landing spots for the deck and it will always be removeable. You could probably use 3/8" ply at this point because it will be fully supported by the foam.
 

seanymph85

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This is an interesting idea. Not something I would have thought to try. How would one go about "pouring" the flotation foam and do you know where it can be purchased? I would assume one would have to block the foam so it doesn't go under the seats. With the exception of having a channel for drainage. I assume a piece of pipe or something going under the seats. Not sure how you would determine about how much foam would be required in each section. Would it adhere of it's own accord to bottom of deck material? Does it shrink during the curing process? The butchers paper sounds like it would provide adequate release between foam and bottom of the boat.

Any procedural details of pictures on this process would be helpful.
 

83mulligan

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This is an interesting idea. Not something I would have thought to try. How would one go about "pouring" the flotation foam and do you know where it can be purchased? I would assume one would have to block the foam so it doesn't go under the seats. With the exception of having a channel for drainage. I assume a piece of pipe or something going under the seats. Not sure how you would determine about how much foam would be required in each section. Would it adhere of it's own accord to bottom of deck material? Does it shrink during the curing process? The butchers paper sounds like it would provide adequate release between foam and bottom of the boat. Any procedural details of pictures on this process would be helpful.
I just did a bunch of foam work. Check out the thread in my signature. Most of your assumptions are correct. It's trial and error on the expansion, you just need to allow it someplace to escape. It sticks to everything in a boat, yet it's easy to lay plastic and make it removeable. Check out us composites for supply. Iboats may carry now, not sure.
 

sgilbert14

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HI, I was reading your post and am doing some floor work myself. I love the foam idea, never knew that this was possible and think this is the route that I will be doing as well. Thanks not to determine the strength and quantity needed for a 88 Grumman 14' Fisherman...
 

jbcurt00

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Sgilbert, please notice when a topic was last posted to. After 90days w no new posts, topics are considered inactive and should not be posted to. This is covered in both the rules and the helpful tip at the top the forum

Its been over a year since SeaNymph logged on to iboats.
 
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