Leaking fuel tank

[ynot]

Just wanted to ask, when is enough, enough ?

Just when everything is sorted, and we have been spending quality time on the water, the fuel tank sprang a leak.

Lucky it was on the trailer under cover.

I have pulled the floor up and I found the boat was built around the tank.

What are my options?

My plan is to take up the couple of bits of timber you can see. They are only screwed on.

I was thinking of jumping on on the tank and trying to crush it in, so I can get it out.

Assuming I can get it out, that leaves me with question of what to do to replace it.

Is a bladder an option? A poly tank?

Getting a full sized tank in, will be impossible.

My poor wife just looks at me.

She loves the boat, but she is biting her lip at the moment.

Any advice would be appreciated.

[mmwjr]

Sorry to hear this happened but at least it’s towards the end of the season. A lot more work but if the engine is removed you can cut out the bulkhead and slide the tank back to get it out and install a new one. I’m not a fan of using a bladder tank as the full time primary tank but would go with either another aluminum or poly tank. One or two smaller tanks are an option but mat reduce you range. If you have to cut the tank first flush it then refill with water to minimize the risk of explosion.

[ynot]

Thanks for your encouraging words Mike.

Its spring here on the east coast of Australia.
We have been picking the eyes out of the days and spending some chilly, but cozy nights aboard.

Taking the motor out, is gold standard, but is out of my league without professional help.

Having slept on it again.

I am easy with taking out the bulkhead and getting the tank out by hook or by crook.

Thinking I will get a custom alloy L shaped tank to drop straight back in.

Take it for a run, check everything is ok.

Glass it back it. Put the floor back on . Glue carpet on.

Ready for summer.

Phew

[mmwjr]

Phew, good luck and keep us posted on the project.

[ynot]

Most of the fiberglass and rear bulkhead has been removed.
No sign of the tank moving yet.
But I had a thought!!!

I am going to get a piece of wood and place it across the gunwales.
I am going to get a car jack and wind it all the way out.
Attach the jack upside down on the piece of wood.
Place a rod inside the tank through the sender hole.
Attach with a rope to the rod and the jack and wind it back up.

Presto, one loose tank
Anyway that's the plan.

[mmwjr]

If that doesn’t work a pry bar from the engine compartment may allow you to get the end of the tank loose. Look for metal retainers near the corners, I’ve seen some tanks held that way. Pictures would be nice of you work.

[ynot]

A pry bar is an option.

The other plan on jumping on it and bashing it may not be as easy as it seems. The tank has two baffles in it, and the welded seems look pretty solid.
Must be pretty poor underneath.

Long weekend here, hopefully I get some time to have a crack at it.

Stay tuned.

[mmwjr]

The under side is exposed to bilge water which is the reason it fails.

[ynot]

Yes, the underside will \be interesting to look at that.
I have a plan for that as well.

The jack I planned on using is in my wife's car and she is at work.

So I had a go at my jack.

Who would of thought it work upside down.

Anyway you get an idea of Plan A.

[ynot]

Ok. I got a chance to grab my wife's jack.
First attempt didn't work. I put it down to the wood flexing.
Second attempt.
Changed the wood to sitting on it's side.
Still didn't work out. I put this down to the rope and wire stretching.
Third attempt.
I thought I put a chain on it.
I thought I was going to have a win.
Maximum pressure was being asserted about half way through the jack cycle.
I could see the tank starting to buckle where the chain was in the sender hole.
Then the jack gave away.
Scared the living daylight out of me.
I didn't think to get a photo of the broken jack.
I managed to get the jack back together.

The lesson I learned is:
Jacks are supposed to used upside down.

Back to the drawing board.
.

[mmwjr]

A come along would have been better but I still think the tank would flex where you’re grabbing it before coming free.

[ynot]

I am not sure what a "Come Along" is. If you mean a Pry Bar? I gave that a good shot as well.
I am convinced a block and tackle would of budged it.
Any way, I will keep plodding along.

[mmwjr]

Here’s a link.

https://www.harborfreight.com/4000-l...SABEgLCqfD_BwE

[mmwjr]

BTY did you verify that the tank isn’t foamed in? If so you can take a hacksaw blade to cut the foam along the sides of the tank, not doing so will make it nearly impossible to remove.

[ynot]

Ok, the latest update.

The tank is out. it was wedged in pretty tight.
I could lift it, but where it was sitting under the sink made it impossible to get it out.
So I cut it out.
Quite scary. I flushed it three times. Filled it again. Put on what PPE I had laying around.
And I left the hose running while I cut it.
Once cut in half, it came out easy.
I found it was sitting on two sheets of ply. One was glassed in and rotted away and the 2nd was floating under the first and had rotted away.
Now to dry it out. Replace the false floor it was sitting on and get a new tank made.
The leak ended up being right at the back, up against the rear bulkhead.

[mmwjr]

Pretty typical tank installation for most builders, crappy.

[ynot]

Ok I have arranged a custom Alloy tank.
I have pulled out all the rotten wood in the tank floor and bulkheads.
A lot of rotten wood smelt like petrol.
Currently cutting new timber to fit.
Will waterproof and then glass in.
Then drop the tank in.
Give it a run.
Put the floor and carpet back in.

Then you never know.
I might even get to enjoy it.

[mmwjr]

What size tank are you putting in?

[ynot]

Good question.

The tank is 200 liters or 52 gallons.

I think I will loose about 20 liters or 5 gallons.

It will be a L shape.

[mmwjr]

That will make it easier to install.