How to cut thick steel?

[Razorfish]

Hi

just a thought but it sounds like an awful lot of work to fix what is, I assume, a relatively small leak and no doubt of it is as big/heavy as you think this may affect the the boats trim unless your going to replace like for like. So why can you not just plate it by either grinding or cutting back to good metal and welding in a new piece.

Make sure you wash out the tank prior and leave it to vent for a few days before letting in a new plate. Most competent welders would find this a simple task and provided the access is ok getting a welder to do the job for you should be easy.

Regards

+1

 

[grumpy_o_g]

Just a thought but, before you start cutting them up have you worked out what you're going to replace them with and how you'll get it in there?

 

[Pete7]

Might be worth watching this and the owner may be a member of the mobo forum.

http://youtu.be/xKWxFiKLzEE


[/QUOTE]


Pete

 

[electrosys]

Most competent welders would find this a simple task and provided the access is ok getting a welder to do the job for you should be easy.

Meanwhile, back in the real world ...

That's exactly the kind of comment I would have made, before I learned to weld. Access, of course, is a HUGE issue, not just to weld, but to grind back to good metal beforehand.
And as for it being easy to get a welder to do this job - well, just try it - there is a lot of much easier welding work available, so why would someone take on such an awkward job ? Unless it paid exceptionally well of course, but I doubt the OP would want to hear that.

 

[vyv_cox]

Meanwhile, back in the real world ...

That's exactly the kind of comment I would have made, before I learned to weld. Access, of course, is a HUGE issue, not just to weld, but to grind back to good metal beforehand.
And as for it being easy to get a welder to do this job - well, just try it - there is a lot of much easier welding work available, so why would someone take on such an awkward job ? Unless it paid exceptionally well of course, but I doubt the OP would want to hear that.

Very true. Even watching the Tek-tanks video above I thought how nice it would be to have that much space to work in. Couldn't even get an angle grinder to mine and no chance whatsoever of welding in situ. Fortunately, I think mine unbolts and will fit through the locker lid.

 

[ghostlymoron]

We have original 1977 steel diesel tanks and as part of the rewire I discovered a water leak has rusted the underneath of one of them. There is no way they can be lifted out whole, they were put in before the engine, so they have to be cut up and removed. I'm guessing that even though the residual diesel film has a very high flash point the only safe way is to use a saw - but what kind of saw and what sort of blade and is it a DIY job? It's a huge job whatever, the steel is very thick

You don't say whether the tank is actually leaking or just surface rust. If it's not actually leaking, it's not an urgent problem and can be left until next end of season left out. Removing the engine to get them out would be quite an undertaking but may be the easiest option compared with the difficult task of cutting up the fuel tanks in situ and would be my preferred solution. It will also make installing the replacement tanks easier.

 

[Rivers & creeks]

Thank you for all the replies, we're on board now. I've tried to check the steel thickness and it's impossible to say without dismantling the cover. It's less than the 11mm hatch but I can't say by how much. The rust is very bad on one corner, flakey pastry comes to mind as an image. The tanks are absolutely huge, at least 200 litres each, which is overkill for a 75hp engine that never runs over 70% revs. At half that capacity we'd have about 40 hours continuous motoring in the tanks and she is a sailing yacht!

Taking the engine out isn't an option, it's a closed wooden wheelhouse and it would mean - well just tooooo much. Tek Tanks standard 125L tank will fit fine and is the right size to go through the wheelhouse doors, all the flooring comes up to get at the engine room from above, but the tanks are off to the sides, they definitely went in first.

It's a pig of a job, but one possibility is to just cut the front face off the tank and put a Tek Tank inside. It would mean cleaning it with lots of soapy water to prevent a diesel smell and it feels like a bit of a bodge but it reduces the job to a sixth of the whole tank removal job.