Vertical petrol fuel tank?

[thinwater]

If you have a cat AND you are interested in fuel safety you will locate both in the bridge deck. This is just obvious. 40 years as a refinery engineer, so I know the flammable code and practice very well. It's not just about isolating them from living space and ignition sources, it is the easy availability of continuous passive ventilation to maintain vapors below the flammable range.


No way I would put any of these in a hull if I had this wonderful alternative. I've had three multihulls, and they all managed it this way. Bridge deck, vented underneath. Focus on that if safety matters to you.

[thinwater]

As for propane vs. ancohol, I'd vote for propane on a cruising boat. I have alcohol on my F-24 and like it fine for occasional use, but on the PDQ I ran cabin heat, stove, and hot water (shower) on propane. Install it right and maintain it. So nice.

[AndyEss]

Originally Posted by thinwater

As for propane vs. ancohol, I'd vote for propane on a cruising boat. I have alcohol on my F-24 and like it fine for occasional use, but on the PDQ I ran cabin heat, stove, and hot water (shower) on propane. Install it right and maintain it. So nice.

Out of curiosity () - what device did you use to generate your hot water using propane for your shower? I use propane for hot water also.

[Djarraluda]

Before settling on a tank construction it is best to check regulations. EU has some stringent design requirements!
In some Countries around the world, petrol tanks are required to have an earthing or conducting element in the construction to stop static electricity build up. This may be limited to portable tanks only, I really don’t know but It would be inconvenient to discover such a need after you had one built.
Roger

[Franziska]

Hi Roger,

thanks for the thought on grounding.

I'll look into that.

A quick info on grounding brought this up (for the US, so I look further for the EU):

"...
Grounding: All metallic components of the fuel system that are in contact with fuel must be electrically grounded to prevent a static discharge from causing a fire or explosion.

Recent events have caused the boating industry to examine the policy regarding the bonding of plastic body fuel fills with metallic caps and retaining chains.* Existing USCG & ABYC policy states that the bonding of these components is voluntary.* A study by IMANNA Laboratories has shown that connecting the metallic retaining chain and cap of a plastic body fuel fill assembly to a boats bonding system may result in electrostatic discharge from a land-based fuel pump nozzle to the metallic components of the assembly when the boat is not in the water.* This condition does not exist when the boat is in the water due to the equalizations of the ground potentials between the fuel pump nozzle and the boats bonding system.*

It is recommended by ABYC and the USCG that new and existing installations of this type of fuel fill assembly DO NOT INCLUDE any attachment to the boats bonding system. Existing connections should be removed from the point of connection to the boats bonding system to the fuel fill assembly.* Removal of the metallic components of the assembly is not necessary; however, the U.S. Coast Guard and ABYC still require that METALLIC body fuel fills be bonded.*

For further information contact:

ABYC (410) 956-1050*jadey@abycinc.org
US Coast Guard at*Po.L.Chang@uscg.mil*202-372-1077
... "

My fuel assembly will be fully plastic.
I will largely go and fulfill the things I find, but, our boat is a homebuilt boat which has been built before a lot of the new restrictions came into play.
Furthermore homebuilders where not required to follow those regulations at the time, but for our own safety it's wise to follow those findings.

All work will be done by ourselves.

[Chotu]

All plastic is ABYC compliant (the barrel is not, because it hasn’t been leak pressure tested by the manufacturer for benzine/gas/petrol). Plastic from the deck fill all the way through with no metal at all is a good bet.

Out of an abundance of caution, I still touch the fuel nozzle to the boat before fueling to release any static at all. Even though my fuel system is 100% non metallic

[Franziska]

Thanks Chotu.

I just tried to find the relevant EU standart. I know which one is relevant (EN ISO 10088: Small craft – Permanently installed fuel systems and fuel tanks) , but once more I find the stupidity that the standarts are hidden behind pay walls.

Personally I like the European Union in general, but I really think that standarts should be available for the general public for free. Similar to how the US deals with nautical charts.

Anyway I'll find the info eventually.

Regarding pressure test, that might be a risk I am ready to take. The boat is a slow sailboat and the tank is not an integral part of the hull. Neither is the proposed pressure head high or the volume big. Further the free surface is fairly small.

[NorthCoastJoe]

In my Macgregor the gasoline needed to be lifted about a meter to the outboard, never had a problem with the Honda 7.5.

[Franziska]

Little update, we might use a 60l or 100l stainless steel drum instead of the plastic drum.
Usually they are used and certified for storage and transport of highly corrosive materials.

Fits the space intendet perfectly and can be very well secured there.
It has welded in connectors and little free surface when mounted upright, which it will be.

The filler as well as the drum will be bonded, possibly via connecting it to our external rudder shaft. Further research to be done on that.

The location where it is mounted has no electric cables in it except of the fuel gauge and is well ventilated.

[Franziska]

https://www.weser-verpackungen.de/49...spundfass_100l

[Brewgyver]

Originally Posted by Chotu

Yes, you may find some difficulty moving fuel from lower than the Outboards. My outboards are lower than or almost at the same height as the tanks, but they will not run forever after a hand priming with the squeeze bulb. Eventually they stop getting fuel. I think this is because the fuel goes up very hight through a watertight bulkhead, almost to hull deck level, then back down to the outboards in the wells.

A note about outboard fuel pump lift capacity: In the vast majority of small boats using outboards, the tank is ALWAYS below the level of the fuel connection on the engine. On both my RIB and old aluminum 14 foot fishing boat, the tank is roughly a foot (0.3 meters) below the engine connection. In both cases, I typically only have to use the squeeze bulb if the engine has been run completely dry, which I do if I don't expect to be using the engine again within a few days.

I took a quick look online at a current Honda user manual, and it suggests the tank be not more than 3 feet or 1 meter below the level of the connection.

Chotu, sounds like you need to re-route your fuel line!

[Chotu]

Originally Posted by Brewgyver

A note about outboard fuel pump lift capacity: In the vast majority of small boats using outboards, the tank is ALWAYS below the level of the fuel connection on the engine. On both my RIB and old aluminum 14 foot fishing boat, the tank is roughly a foot (0.3 meters) below the engine connection. In both cases, I typically only have to use the squeeze bulb if the engine has been run completely dry, which I do if I don't expect to be using the engine again within a few days.

I took a quick look online at a current Honda user manual, and it suggests the tank be not more than 3 feet or 1 meter below the level of the connection.

Chotu, sounds like you need to re-route your fuel line!

I wish!

I can’t change anything.

The tanks are low in the hull for weight distribution while the “hazardous materials “ box is at bridge deck level for safety.

The fuel has to come up from catamaran bilge level, to bridge deck level, then pass through a Racor filter up there. Only then can it go back downhill to the outboards.

It’s unfortunate, but I don’t see any other way to plumb this, keeping safety in mind.

[rslifkin]

Originally Posted by Chotu

I wish!

I can’t change anything.

The tanks are low in the hull for weight distribution while the “hazardous materials “ box is at bridge deck level for safety.

The fuel has to come up from catamaran bilge level, to bridge deck level, then pass through a Racor filter up there. Only then can it go back downhill to the outboards.

It’s unfortunate, but I don’t see any other way to plumb this, keeping safety in mind.

Could you build a small enclosure for the Racors in the sides of the outboard wells?

[Chotu]

Originally Posted by rslifkin

Could you build a small enclosure for the Racors in the sides of the outboard wells?

Well that’s not a bad idea!

But, the fuel is all on one side (balances out other stuff in the other hull).

So, there is a fuel line through the aft structural main box beam to bring fuel to the second outboard on the other hull.

That means the fuel still has to go to bridge deck level first.

What I need is a good 12v fuel pump that’s quiet and can pull fuel rather than push.

[rslifkin]

Originally Posted by Chotu

Well that’s not a bad idea!

But, the fuel is all on one side (balances out other stuff in the other hull).

So, there is a fuel line through the aft structural main box beam to bring fuel to the second outboard on the other hull.

That means the fuel still has to go to bridge deck level first.

What I need is a good 12v fuel pump that’s quiet and can pull fuel rather than push.

Look at pumps made for electric fuel pump conversions on carb-ed engines. Low pressure and should be fine with sucking a good distance from the tank.