Necessary mods for below-deck fuel tank

[mikemerrill50]

Hey guys. It's been a while since I've posted, and now I'm ready to get back to work on my boat. The picture below is a bit out of date, because I have since removed the foam from the hull, and have since repaired the stringers.
Here's what I'm wondering: I am looking into putting an below-deck gas tank, v-style. However, I know I will obviously have to remove a section of the center stringer, but I might have to remove part of the nearest stringer on either side. What would be the best method of doing this? I was going to cut the stringers where I would need them cut, add some layers of fiberglass to the hull below where the tank would go, and build a frame around the tank to be covered with fiberglass (and of course take into account the expansion of the tank, yada yada). I am also thinking of using heavier foam for added floor and hull support. How does this sound?

Thanks always,
Mike

Here's the link to the picture:
http://rides.webshots.com/photo/1530717708066244682rUSdXy

P.S.... on another note, I the sides of the hull seems a little too flimsy for my tastes. Should I stick with the manufacturer design, or would it be ok for me to add layers of fiberglass to the inside of the hull to strengthen it? Thanks again.

 

[Solittle]

Re: Necessary mods for below-deck fuel tank

I'm a bit reluctant to comment as I have never seen a hull of that size with 5 stringers and I wonder if the manufacturer used that many because he wanted to get by with a thinner hull. I see absolutely no problem with cutting out one for the tank but three of the five???

 

[tashasdaddy]

Re: Necessary mods for below-deck fuel tank

i agree with Solittle.

 

[Frank Acampora]

Re: Necessary mods for below-deck fuel tank

Thanks for the photo. Now I know what the inside of my Manatee looks like. I have the sales literature and the 2by stringers were one of their (the company) measures of quality. They were quite proud of the fact that they used only the highest quality materials (where have we heard that before) and full sized 2 by (whatever height needed) stringers. I will admit, mine (20 foot cuddy) rides quite solidly and handles chop like a much bigger boat. I can also say that the topsides are about 1/4 inch thick.

 

[mikemerrill50]

Re: Necessary mods for below-deck fuel tank

thanks for the responses everyone.

frank acampora, do you feel that your manatee is somewhat flimsy on the sides of the hull? i just mean i can push it in from the outside, and it bows fairly easily. it does not do that in the lower part of the hull.

do yall think I should build a few supports that run up the sides of the hull (on the inside) kind of like a skeleton? or should I leave it the way manatee manufactured it?

also, frank, i'm glad to hear your manatee cuts through waves easily. the waters I ride in stay pretty choppy.

 

[Frank Acampora]

Re: Necessary mods for below-deck fuel tank

You know, I never tried to push on the sides so I ran out right now and did it. A real good push doesn't move the side much more than 1/8 inch. But my hull has foam filled bolsters rising about 6 inches from the floor. Makes for less unsupported side. If you really want to see flimsy sides, look at early Glastrons. They were noted for that.
If you decide to put in support ribs, be sure to cushion them from the hull otherwise they will create a pressure point and show through the hull.
Fiberglass is amazingly strong and it takes a lot to crack it. You would be surprised how far it will bend before cracking. I had a car cross a yellow line and sideswipe my 15 foot Glastron. It knocked off his side mirror but only put a few stress cracks and minor scratches in the gel coat of the boat. Did not damage the base fiberglass. And yes, that Glastron has flexible sides.

 

[mikemerrill50]

Re: Necessary mods for below-deck fuel tank

mine doesn't have any bolsters. i might, instead of building some, just run a few strips of fiberglass (spaced out) up the inside of the hull like bolsters just to strengthen the hull without stressing it too much.

ugh... now back to redoing the stringers.

thanks for the responses.

 

[HookMaster]

Re: Necessary mods for below-deck fuel tank

I think the hull is as heavy as any Fg boat of that vintage and better........Here is what I did to restore my 1978 19' an exact duplicate of yours. I did not opt for a below deck tank. I may have an aluminium custom tank made that should hold about 40+ gallons Go to www.shareaproject.com Search "Manatee"

Good luck

Don

 

[Medic2556]

Re: Necessary mods for below-deck fuel tank

My boat had a new tank installed, or so it seems, and the prior owner left a section of the floor removeable above the tank. (which lead to the demise of the remainder of the floor, stringers, and foam because he didn't seal anything after cutting it, leaving the wood exposed) I was wondering if I should leave it with the ability to open when I replace the floor, or just seal it over. I also wanted to add a ski locker, but some people advised me that may not be a good idea. Any thoughts?