fuel tank issues

spargs

Seaman Apprentice
Joined
Jan 29, 2006
Messages
41
Hi everyone,

well the restoration of my haines 16R is in full flight, the floor has been entirely cut-out and the angle grinder has had a serious work out. fibreglass dust is flying everywhere (hopefully not infesting my lungs!).

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As part of the rebuild, I am installing a 90 litre underfloor fuel tank. The tank is as shallow as possible being only 160mm high. This was the shallowest tank available regardless of whether the tank held 50 litres or 300 litres, so i couldn't have bought a shallower tank.

The way my hull has been built, the stringers are at there deepest in the middle of the boat and taper off towards the aft end. Since I plan to have the tank at the rear of the boat, i have found that the depth of the tank is fine at the centre end but about 10-15 mm too deep at the stern (ie, sits 10-15mm above the stringers.

So, i need a solution to my problem.....

Is it possible to grind/notch 10-15mm into the centre stringer to lower the tank? I plan to install large bulkheads at either end of the tank which should provide lots of rigidity into the hull.

Or do i need to raise the height of the stringers and frames. Ideally i dont want to do this as the stringers are solid.

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On another query, now that the floor is cut out, i need to grind clean areas for glassing. do i only need to grind a 4-6" area extending from the hull to floor joint to key the floor to the hull?

should I grind the tops of the stringers?

Thanks

Nick
 

tashasdaddy

Honorary Moderator Emeritus
Joined
Nov 11, 2005
Messages
51,019
Re: fuel tank issues

the stringer are solid i would ad on a tapered strip to the top of the stringer and cross members raising the rear floor. glass it in . go with the tank and floor. why would you want to cut into a solid stringer.
 

Mark42

Fleet Admiral
Joined
Oct 8, 2003
Messages
9,334
Re: fuel tank issues

The center stringer could be cut down the 15 mm you require, then "sandwitched" between two additional supports to regain any lost strength. Glass it all in go. 15mm is not a lot, but it depends on how tall the stringer is where you want to remove 15 mm. From the first photo, you have the room to add the sandwich supports.
 

spargs

Seaman Apprentice
Joined
Jan 29, 2006
Messages
41
Re: fuel tank issues

i like the idea of the sandwich method. That coupled with bulkheads should provide ample support i would have thought?

Cheers

Nick
 

dmarkvid2

Chief Petty Officer
Joined
Nov 29, 2005
Messages
478
Re: fuel tank issues

How big is 10-16 mm? I'm not up on the metric system. Anyway, if you did that, be sure to glass the area you cut away for strength. And were a mask when you grind fiberglass!!
 

Bondo

Moderator
Staff member
Joined
Apr 17, 2002
Messages
71,148
Re: fuel tank issues

10mm is just under 3/8ths"........
16mm is 5/8ths"..........

I'd go ahead,+ Grind the center stringer to Fit..........
 

ondarvr

Supreme Mariner
Joined
Apr 6, 2005
Messages
11,527
Re: fuel tank issues

11mm is 7/16 14mm is 9/16

You could just add more glass to the side of the areas you trim off, you wouldn't really need to add more wood, but either way will be easy and work fine.
 
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