Drilling into a aluminum fuel tank

[pwilletts]

I would like to install a fuel sending unit in my tank...its aluminum...there is no other way short of using a stick, to measure the quantity...the issue is the aluminum filings/bits that will end up at the bottom of the tank...the pickup tube is about 1" above the bottom.... there is no access to the inside of the tank...here are of course filters but I don't like the idea of metal filings bouncing around inside..any suggestions??

[Guy]

Use grease on the pilot drill bit to catch shavings, then stop short with the hole saw. You should be able to knock out the slug.

[Panope]

You can omit the pilot bit all together by first drilling (with the holesaw) a hole in a piece of plywood. Then clamp, glue or wedge the plywood on to the tank, thus keeping the holesaw located.

Steve

[Cheechako]

Open the tank cover and hold a bowl under where you are drilling.

[Captsteve53]

1)Drain the tank first, use the above mentioned good idea's but before fitting the
sender unit use a vacuum cleaner with as big a tube as can fit in the hole to do a final clean up ,
2) If no inspection cover then may be a good time to cut an opening in the tank allowing access to do all your fitting work/cleaning then place an inspection cover plate in the tank, making it easy for any future cleaning,

Cheers Steve

[Terra Nova]

Install a cleanout with the sender mounted to the cover plate.

[SaltyMetals]

If I am not mistaken www.gobius.se do an external unit whereby various sensors are applied to the outside of the tank. No drilling, no holes. I installed one of their systems on my SS holding tank. Wonderful bit of kit and all you see is a plate about size of a visiting card with various lights. Maybe good for a holding tank showing lights for 1/4, 1/2, 3/4 but no more than that. If you need to accurately know how many litres/galls are in you tank then this would not suit. But then how many of us actually have an accurate fuel sensor anyway?

[Guy]

Originally Posted by Captsteve53

1) use a vacuum cleaner with as big a tube as can fit in the hole to do a final clean up ,
Cheers Steve

Hold up there. Diesel may not be that explosive but running the fumes through the electric motor in a vacuum could blow you up. An air vac is the proper piece of equipment.

[kentobin]

I've cut holes in wood with someone using a vacuum cleaner and the crevice tool attachment to vacuum up the dust and shavings as I was drilling. It should also work on metal just cut slowly so the metal particles are small. If you have a strong enough vacuum you may be able to just use the vacuum hose without an attachment. I still see a problem as the drill bit or hole saw breaks through into the tank.

There are vacuum attachments for drills but they seem designed more for dust than metal shavings. They look interesting but expensive. Amazon has one for only $30 but most are $100+. I've never used one so this is not an endorsement.

https://www.amazon.com/BitBuddie-Uni.../dp/B0019KFG9A

[Dave_S]

I assume with an aluminium tank and diesel the risk is reduced but there may be some chance of an explosion?

With petrol tanks we used to fill them with water and drill them while they were full of water to make sure there was no air fuel mix in the tank to set off.

[jamhass]

Use a bit of grease as suggested above, clean the bit as you go. Have a vacuum nearby, don't really need anything fancy. If paranoid use a plastic container like a 1-pint deli container to "focus" the vacuum at the bit. Then, don't sweat any remaining chips. They will be big enough to be caught by filters, but small enough to not bother the pickup tube. In all probability, they will simply fall to the bottom of your tank and get trapped by the sludge that is already there.

[noelex 77]

The Tank Tender system uses a very narrow pickup tube, that only needs a small hole drilled on the top of the tank. It is also a good system, so may be worth considering.

[nauticalnomad]

Theres is a better option.. YOu can get these stick on guages to the side of the tank but you need access to the sides to view.

Or if there is an in let and outlet that are screwed fittings you could use some tees and put a site glass on it somewhere.

If you need to drill into it.
YOu could always cut a big square in the side of the tank or the top and then drill your required holes extra for the guage and when finished and the tanks cleaned out via the opening you have cut out you then use proper mastic and some perspex to seal over the hole along with some pre self tapped holes to secure. Run a small bead of mastic around the outside of the cut out and wait till it cures and then screw the perspex down to compress the mastic and seal the opening. There isnt that much pressure in the tank to create a leak.

[Pete7]

Sound like you have no way of inspecting the inside of the fuel tank which can be a problem on a yacht. Fit a decent fuel tank hatch first will allow you access to drill the fuel tank sender hole and clean the tank afterwards:

Whale Henderson Watertight Inspection Hatch TCL4 - £23.95

[a64pilot]

Do the grease trick, almost no filings will go into the tank and a few won't matter, filter will catch them