Thread: Fuel Tank Hatch

Peter, I see you've had no reply to this. I'm not sure I'm really qualified to help, but I'll try anyway -- maybe it will give some impetus to someone else with ideas.

First, without knowing anything whatever about your vessel or her tank, is there any way at all of getting the tank out of the boat? My putt-putt's tank, for instance, was fastened under the foredeck with a couple of stainless straps that could be unscrewed. So although the tank couldn't be drained from underneath, disconnecting the hose and deck-filler and removing the straps allowed the whole tank to come out for draining and cleaning. And although there was no drain plug, there was the fuel-tap hole which, along with the filler hole, was then available for use to drain from.

If the tank can't be removed, then your scheme doesn't sound unreasonable to me. As the tank has already had fuel in it though, you'd need to be careful not to create sparks at any time. It's an aluminium tank, so that's a good start, but I'd use air (or hand) tools rather than electric for any cutting or drilling.

What shape is the top of the tank? Would it be easier to cut out a rectangular panel than a circular one? And could you use the cut-out piece as the hatch itself, by fitting the opening with an H-section (petrol-proof) gasket, like they do with car windscreens? If you could snap the cut-out back in, that would avoid the need to cut a new cover and then to drill and screw to fasten it over the opening.

If that wouldn't work, will the tank wall material be thick enough to tap for machine screws? Or might you have to think of glued-in nuts inside the tank to fasten into instead?

If you do have to cut the tank, then I'd go for a larger opening rather than a smaller. It would make for easier cleaning, as well as for easier cover-fastening if using the H-section method (although of course more screws would be necessary if you have to use a screw-down cover.)

Just thoughts off the top of my head I'm afraid....

Mike,

I appreciate your thoughts, which as it has turned out, are not too different from my own line of reasoning. The job is now done. My experiences might be useful to others.

Luckily I had the wit to anticipate a baffle, so I cut two circular holes of about 160mm diameter on each side of the weld marks that gave me the clue to the baffle placement. I used a drill - small holes and then large and then a good smoothing-off with coarse emery cloth. Not pretty but fast. I could I took advice from someone who had worked in the fishing industry and fitted circular 3mm aluminium covers with Sikaflex. Glued 'em on! No tapping, no threads. What a practicable solution!

The gunk in the tank was horrible - fungus residue and other unmentionable dross and silt, plus all of my newly made aluminium detritus. It had likely not been cleaned in 40 years. No wonder I ran into strife and no wonder all of the other methods for getting gunk off the bottom were not successful.

One of the larger problems was getting the 150 litres of fuel out and getting it back clean. A couple of plastic garbage 'tins' plus the few decent jerry cans I could find did the trick.

I was pleased to find the interior aluminium as shiny as the day it was made. I have heard others say their tanks had started to oxidise.

I now carry 2 sets of spare filters and a spare glass bowl - but that is another story that led to the need for a proper cleanout.

Thanks again for taking the time

Regards
Peter

Bio-diesel, eh?

Glad it worked out okay, Peter. Cheers.