Installing a fuel tank access panel

[storysunfolding]

I picked up a 17 foot sunbird corsair 170ss to replace my 1969 trihull. Not only does it seem to be a superior boat but it cost less than putting a floor (and alot of money) into a boat from 69 with no resale value.

The one thing that concerns me is that the fuel tank is under the rear floor and other than a small access hole, there's no way to get down there. This hull has been sitting for some time and I want to be able to inspect and service the tank (metal) and all hoses (don't feel in teh best condition to the touch.)

What I'd like to do is put in an access hatch over the fuel tank. Around 3 feet by 4 feet. While I know this may hurt the structural integrity of the boat as I've read that the floor adds much to this, how bad would this be? Is this a bad idea?

Thanks

 

[sdunt]

Re: Installing a fuel tank access panel

The structural thing would depend on how you re-installed the hatch. If you had hinges and a latch on it like a door, it wouldn't do much for the structure and you would likely feel it move when you walk over it.

If you glue or 'poxied blocking on the underside of the floor around the hatch and then screwed or bolted the 'hatch' back in place that would give you more structure. The fun part is trying to figure out how to fit the blocks in around the tank and also how to 'screw' it down and not puncture the tank..

For me I'd go with the blocking and screwing the hatch back in place. Also consider that you could use 1/8 inch or 1/4 inch thick aluminum as the blocking under the floor and thread the aluminum to take bolts that you have cut off to the exact length needed to hold the hatch down.

If you can not find aluminum that will work locally, Home Depot, etc Check out www.onlinemetals.com

 

[storysunfolding]

Re: Installing a fuel tank access panel

I'm not sure how I'm going to do the blocks... Unless anyone thinks that this will cause a problematic structural problem I may just start with a hinge and latch for my boat/motor water test this weekend. If all goes well on Saturday I'll spend Sunday troubleshooting the blocking.

 

[tashasdaddy]

Re: Installing a fuel tank access panel

you should be ok. stay atleast a 12 inches for the outside of the boat.

 

[storysunfolding]

Re: Installing a fuel tank access panel

Ok- So I pumped out the old fuel last night (everyone likes the smell of bad fuel right?) and there was alot of crap in it. I definately have to take the fuel tank out either to replace it or for peace of mind that I reconditioned it well enough. I plan to cut my hatch out tonight and see how she goes.

I did have one worry though. The tank previously had a small plastic cover in the floor above it to inspect the tank maybe 6 inches in diameter. When I removed that the wood around it seemed a bit soft. Is that common around a cover or the first sign of big troubles to come? The boat had been kept under a cover and the floor didn't feel soft anywhere when inspecting it. I went ahead and drilled some holes to ease my worries in the area I planned to cut out and the wood shavings were dry and a good color.

 

[tashasdaddy]

Re: Installing a fuel tank access panel

the mfgrs are bad about cutting holes after glassing and not sealing the edges. unsealed edge is the first place for rot.

 

[storysunfolding]

Re: Installing a fuel tank access panel

So my panel may just save my floor... or my floor is probably already toast?