Fuel tank opening hatch

zoidberg

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In my refurb'ing saga, I'm looking anew at my now-firmly mounted diesel fuel tank. It holds, I calculate, about 35l, is constructed of stainless sheet, and has 'nipples' for fuel input, breather, supply and return. There is no inspection hatch/orifice for periodic gunge-cleaning. I thought when I'd freed, steam-cleaned then remounted this tank - presently empty - that I'd probably not need an 'inspection' hatch. Now I'm not so sure.

I CAN cut thin sheet stainless with the tools I have, sufficient to make an opening and drill holes for fasteners. I CAN inspect inside using a cheap Chinese endoscope and I reckon I CAN swab up any swarf which accumulates inside, with gunge ( technical term for the residue of cladosporium resinae and its other noxious mates ) acting as coalescent particulate matter i.e. it clumps.

There was a redundant reference to a Vetus kit for this task. The link I found failed. Is anyone able to point me to a working link for that or similar Inspection Hatch kits?
 
Thanks, VicS
That looks promising. I'll do some 'measuring up' to see whether I can fit it without removing the tank again.
 
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I have had issues with blocked filters and engine dying when you really didnt want it to so set about cutting four holes to allow access for manually cleaning the tank. If I could offer one piece of advise it would be to measure the diameter of your arms before deciding on hole circumference.
 
I made my access hatched big enough to get your head inside to look around to ensure all the rud is removed

If you cannot make it that big to get a camera in for view all parts
 
You proposed tank is small, which implies you will either not use much fuel and/or it will frequently be re-plenished - and thus the fuel will be fresh. Additionally as your tank is so small you can fill the tank from a jerry can, or 2, which can have fuel from a motor vehicle service station (so the fuel should fresh).

It is commonly suggested that Marina fuel may contain more water and be older then service station fuel. The latter wins on the cost stakes as well - though filling a 35l tank should not break too many budgets.

I know different location and different source of fuel - but our tank was 200l, we religiously filled from terrestrial service stations and after 25 years never had an issue with fuel (and did not have a 'service' hatch in the tank).

Are you really sure you want to have a service hatch in such a small tank?

Jonathan
 
If you're going to have extra holes in a tank, a fuel gauge is quite nice to have.
Otherwise, a big hatch is just a potential for leaks.
 
I had an old, small tank that never had an inspection hatch. Retrofitted one that is big enough for me to reach in and touch every corner of the tank. I am very, very glad I did - I removed large amounts of horrible bug-gunge. Based on that experience I would definitely recommend it. I wish I'd found the Vetus product that VicS links - it looks easier than my solution.

I cut the hole with a jig saw, saving on buying a giant holesaw, but my tank is only mild steel.
 
I think the requirement for inspection hatches will depend where in the world you are as the quality of fuel sold varies significantly. Here in the UK we are now using higher bio content which it seems results in shorter shelf life and water content resulting in more issues of growth and sludge.
 
If possible, if the tank is deeper, say incorporated into the top of an encapsulated keel or moulded into the hull sides, use a round lid and not a square, or oval, or rectangular lid. Round lids can't fall into the tank via the lid hole. A right pain fishing out a lid accidentally knocked into the tank.

I note the Vetus link is round.
 
How to clean fuel tank

Regarding round access hatches

Has any one tried to cut a 129mm or a 160mm hole in a steel tank using a hand electric drill

I have not easy

I would use at least a mag drill machine
I fitted four at only 100mm and that was on an aluminium tank. The kick back from my drill nearing the end of the cut was fierce.
 
For drilling such holes a tank cutter is best.

Do you mean one of these


hexagon-shank-tank-cutter_min_17775_P_1.jpg



You need a very rigid drill mounting to use one of these

I have one but a hole saw is much easier to use by hand
 
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