Removal old steel fuel tank

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blan321

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Hi
My Southerly 100 1989, has mild steel fuel tank behind engine, only way to remove intact is prior removal of engine. Could remove sliced parts thro 1/4 berth side access.

Tank has corrosion and I suspect pinholes, P.O. fitted plastic tank below main companionway below raised floors, not well strapped down and limits access.
Option 1 is to slice top off old leaving lip and get new shallow plastic tank made that would slide thro from 1/4 berth access into this formed tray.
Option 2 is new shaped tank below large stbd cockpit locker false floor, where I believe located on S105. I would rather remove old tank completely in this case, without lifting out engine.
A previous southerly owners assoc post reported too thick steel for air shears, they used angle grinder to chop up.
Rather not do that, mess, they has fire, and some report even diesel vapour explosive.....
So any clever ideas before settle on engine removal next winter please?
Thank you!
 
I would probably use thin (1mm) discs in an angle grinder. Yes, it is messy and noisy, but it is quite difficult to ignite old fumes, esp if you take a bit of time to purge them. Big plus, it is quick.. I cut up a tank that was 1.5mtr diam by 3mtr tall in about 2hrs ( not in a boat) with a plasma cutter. Far more likely to cause problems with vapour, but took the usual précautions.
 
I had leaking tank on my 1986 S115 and a right pain.
The temporary answer was to fit a plastic Vetus tank above it and carry on.
THe permanent answer was to get it out and fit a new stainless tank. This could only be removed by cutting open the wall of the cockpit below the cockpit locker. By cutting the cockpit wall you massively increase the space available to get the thing out.
When the job was done I got onboard and didn't even notice/forgot the wall had been cut - so good was the repair to the GRP. Job done a long time ago at Eversons, Woodbridge.(in which I have an interest, hereby declared).

Not sure if the S100 layout is the same as the early S115 but, in any event, do not discount chopping away large parts of your cockpit and then putting it back again - it is not only wooden boats that can do this !
 
A reciprocating saw aka sawzall is one weapon. Or eve a jigsaw.

The fumes, such as they are, can be got rid of with a wallpaper type steamer.
I'd probably use an angel grinder, steam the tank first, then use plenty of old dust sheets or similar to catch the dust and sparks.
The fallout will be fairly hideous, sparks will get into the surface of anything they hit and the dust will cause rust stains if not removed immediately.
Dust mask and ear defenders for sure!
 
Had to remove a galvanised water tank from just about the most awkward and difficult spot you could possibly hide anything in on my Princess 33.
The only way was with an angle grinder and the only access was lying on your side in narrow tunnel under the side deck.A pig of a job.
Replaced it with a slighty smaller plastic tank which had enough flex to force it back past stuff that was in the way.

Next time would cut the boat in half to get the tank out.:( simpler and easier. Never ever agin.
 
I would not worry about chopping bits out of a GRP boat, it is so easy to repair: consider the cost/benefit in terms of time, hassle, danger and filth. IMO lifting the engine is the easiest, 6 coupling bolts, 4 engine bolts, 2 starter cables, one wiring multiplug and two pipes. And a crane/hi-ab. Or would be on my boat, maybe not the case with yours.
 
Hi all, many thanks for helpful comments and advice. Seeing the spread of comments especially about chopping the steel in situ I am moving towards fisherman's advice, engine removal maybe not so bad after all. I just need to check fuel tank will then pass!
Added advantage it gets a good "going over" at home! The access for steel cutting is horrible, i will photo at weekend and post to illustrate.
 
So I thought an update would be interesting, and I have one question too on sensible fuel tank size at end of post.
At end of season after liftout I took out engine yanmar 2GM20 using boom, halyards and block and tackle. After clearing out pipes, filters etc then cut out GRP covering feet of fuel tank with sharp wood chisel and fuel tank out too.
Incidental discoveries:
1 first section of exhaust hose lining had detached and collapsed, ready to block exhaust at any time. I suspect was too small diameter for pipes (see 3!)and also 28 yrs old.
2 inside propshaft coupling fretting on shaft, roll pin worn away, Allen bolts not all tight. Ready to lose grip at any time soon......it was a devil to get roll pin out, hardened steel, would have been almost impossible with engine there. No drive problems noticed during season, only removed to replace stuffing box rubber hose.
3 small water leak inlet pipe of water muffler because GRP inlet pipe had been slit to allow some compression to allow tight exhaust hose on......CO monitor hadn't sounded but presumably small risk of gases leaking too.
So, those faults now tackled.
P.O. has fitted 60 litre Vetus tank under floors instead of original 120 litre steel one behind engine.
The vetus is sound, I can easily make up timber shelf where steel tank sat.
My question please, is 60 litres enough? Southerly 100, 9.6m long, fuel consumption approx 2 litres per hour, so say 26 hours motoring. Channel, Solent, Brittany and channel islands cruising at most, some single handed so engine quite important.
Thanks again for all the advice previously, removal of engine was right on more than one count!

PS lots of engine maintenance done too, easy on work bench at home. I think it took less than 2 hrs to swing it into boot of car from boat. Boatyard quite surprised!
 
Well done and thanks for the update, always interesting to read how things turn out.

60 litres sounds enough for most occasions, a couple of plastic jerry cans gives you 100 litres total.
 
We have Bene 361 with an MD2030 - similar size boat and fuel consumption.

The tank is 75 l which everyone says is on the small size, but we have never come near to running out, even when we had to motor about 200 Nm. We do carry two spare 10 l cans but have never had to use them in anger.
 
Having a spare 20 l can works for me. Just have a think about how to get it into the main tank under possibly difficult conditions. I have a length of pipe with a hand primer (as for outboard motors)
 
Interesting reading this post as I had to do a similar job on my Moody 33 which had a leaking 40 gallon fuel tank. I got the old tank out but had to cut into 3 pieces with a reciprocating saw - excellent tool, much better than an angle grinder, very quick, but had to rotate the tank to be able to cut all round and lift out each piece. Well worth it, a previous owner had tried to repair it with epoxy? or something. Replaced with 91 litre Plastimo plastic tank which gives me about 30 hrs motoring.
 
blan321 said:
So I thought an update would be interesting, and I have one question too on sensible fuel tank size at end of post.
At end of season after liftout I took out engine yanmar 2GM20 using boom, halyards and block and tackle. After clearing out pipes, filters etc then cut out GRP covering feet of fuel tank with sharp wood chisel and fuel tank out too.
Incidental discoveries:
1 first section of exhaust hose lining had detached and collapsed, ready to block exhaust at any time. I suspect was too small diameter for pipes (see 3!)and also 28 yrs old.
2 inside propshaft coupling fretting on shaft, roll pin worn away, Allen bolts not all tight. Ready to lose grip at any time soon......it was a devil to get roll pin out, hardened steel, would have been almost impossible with engine there. No drive problems noticed during season, only removed to replace stuffing box rubber hose.
3 small water leak inlet pipe of water muffler because GRP inlet pipe had been slit to allow some compression to allow tight exhaust hose on......CO monitor hadn't sounded but presumably small risk of gases leaking too.
So, those faults now tackled.
P.O. has fitted 60 litre Vetus tank under floors instead of original 120 litre steel one behind engine.
The vetus is sound, I can easily make up timber shelf where steel tank sat.
My question please, is 60 litres enough? Southerly 100, 9.6m long, fuel consumption approx 2 litres per hour, so say 26 hours motoring. Channel, Solent, Brittany and channel islands cruising at most, some single handed so engine quite important.
Thanks again for all the advice previously, removal of engine was right on more than one count!

PS lots of engine maintenance done too, easy on work bench at home. I think it took less than 2 hrs to swing it into boot of car from boat. Boatyard quite surprised!
Click to expand...

I think now you have come this far it would be a shame to compromise on tank size. One day on a long passage you will regret it. Sell the old plastic tank on ebay and buy a new plastic one closer in capacity to the old steel one.

Www.solocoastalsailing.co.uk
 
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