Steel in Keel Fuel Tank Overhaul or Plastic Tanks

[On The Water]

Originally Posted by Rustic Charm

I appreciate your suggestion, but just a couple of problems with it,

A. I'm not in Melbourne
B. The inspection hatch in the forward compartment is 50mm at its widest and 20mm at the narrow end and;
C. Baffles in the tank mean I can't see the entire tank, yet alone blast it with a steam pressure system.

I actually have a friend with a high pressure steam cleaner. It would cost me nothing to use it. But, I can't get it in where it needs to go. In addition, there is some form of plastic sealer that's been dropped or dripped into the bottom of the tank. I suspect that is hiding some rust or gunk below it. If I cut the tank out then I'd dig that out and see what the steel is like below it.

Not you.
A professional outfit with professional equipment!
The 50 mm and 20 mm inspection plates are a bit small, maybe they can be enlarged with some nibblers & Shears and again not talking about home equipment. If its under 5 mm thick one can just get a pro outfit to punch a bigger hole in it with a hydraulic thingy and then make a bigger inspection plate might require a few punches going from the biggest that fits in to the next size, a decent whole saw will also cut 5 mm steel a few times with no sparks but definitely some heat if one is not careful.


Steam cleaning, suction out fit. The steam cleaning end definitely does not need to be solid, there are nice pressure hoses for that and im talking about basick steam washer staring at around 300 Kg dry wight, maybe 400 Kg, so not light weight stuff, just make sure your inspection plates are big enough so the whole tank docent blow, well let them figure it out that's what you paying for.

[Snowpetrel]

Originally Posted by Rustic Charm

They were 30's in the racor's. I think the engine one is a 10.

I'm am thinking carefully about cutting an access into the keel tank from the outside. Something the size of a 1m by 1m would do it nicely I think.

Sounds like the filters are about right then, if you had used 2 micron then it that would have explained some of the blocking.

Anybody know if a blocked filter is likely to damage or stress a injector pump. I would have thought the low presure would have sucked air and stopped the engine quickly before any real damage is done. But I guess running with negative pressure and air would be hard on the injector pump.

I have heard that there are sometimes tiny mesh filters inside the inlet of the injector pump. Prehaps this has blocked. If so its an easy fix, but I would have thought the mechanic would have considered and checked this, and your engine may not even have this filter.

I've seen plenty of steel boats where they have cut access holes in the hull. Often its the easiest way. Just make sure you dont set the tank on fire, and also you will need to carefully cut around any floors or frames. I wouldn't cut out a hole as big as 1mx1m I would go as small as I could get away with, with a nice corner radius.

[Rustic Charm]

Originally Posted by Snowpetrel

Sounds like the filters are about right then, if you had used 2 micron then it that would have explained some of the blocking.

Anybody know if a blocked filter is likely to damage or stress a injector pump. I would have thought the low presure would have sucked air and stopped the engine quickly before any real damage is done. But I guess running with negative pressure and air would be hard on the injector pump.

I have heard that there are sometimes tiny mesh filters inside the inlet of the injector pump. Prehaps this has blocked. If so its an easy fix, but I would have thought the mechanic would have considered and checked this, and your engine may not even have this filter.

I've seen plenty of steel boats where they have cut access holes in the hull. Often its the easiest way. Just make sure you dont set the tank on fire, and also you will need to carefully cut around any floors or frames. I wouldn't cut out a hole as big as 1mx1m I would go as small as I could get away with, with a nice corner radius.

I 'think' this is the right picture. You can see someone has in the past cut into it. I propose instead of a small hatch, I'd make a large one to which I can get into both sections of the tank. This small one would have been only into one part of it.

[Snowpetrel]

That looks ugly! Its pretty easy to cut holes out with a skinny disk on an angle grinder. The corners are harder. If you are going to reuse the old plating the way I did it was with a jigsaw. Very very slow, but a narrow kerf.

I have also just cut a square hole with an angle grinder, but its weaker than a nice say 50mm radius.

If you are going to put in new plate then you can use a hole saw for the corners and then cut between the holes with an angle grinder.

At least cutting out the sides will give you an opportunity to really check the condition of the steelwork inside the tank. Shame that you will need to recoppercoat the weld and maybe the new plate.

Do you have any more of the paint? If its going to be a while before you fit a new engine you could leave it a year or two and do some other welding at the same time. Engine beds might need some work...

[Rustic Charm]

Originally Posted by Snowpetrel

That looks ugly! Its pretty easy to cut holes out with a skinny disk on an angle grinder. The corners are harder. If you are going to reuse the old plating the way I did it was with a jigsaw. Very very slow, but a narrow kerf.

I have also just cut a square hole with an angle grinder, but its weaker than a nice say 50mm radius.

If you are going to put in new plate then you can use a hole saw for the corners and then cut between the holes with an angle grinder.

At least cutting out the sides will give you an opportunity to really check the condition of the steelwork inside the tank. Shame that you will need to recoppercoat the weld and maybe the new plate.

Do you have any more of the paint? If its going to be a while before you fit a new engine you could leave it a year or two and do some other welding at the same time. Engine beds might need some work...

I have a litre, which is enough to redo the Copper Coat.

I'm thinking, that I can plan on removing the engine and get it ready for removal on my mooring. Then I'll pull it up on to the club slip. For a limited time, perhaps two weeks, where I'll pull the motor and at the same time, do the work on the keel. As soon as it's done I'll put it back on the mooring where I can prepare the engine bay and do everything else I need to do, such as repsinting it and setting up the filters and fuel polisher again. To re-engine, I'd like it in Launceston. So, I'd have to get it towed up for that and then out on the slip in my usual slip yard.

[zeehag]

intrinsic fiberglass. built into my fg hull, low n heavy. i will be converting all tanks to fg, built into hull.
i do have good inspection ports, which makes a huge difference.
if you go in via side of tank, make sure you have a good method of sealing so as to prevent cat ass trophic fail.

life is an adventure meant to be LIVED!!!

[grjfield]

Looks like a good opportunity to switch to electric and say goodbye to diesel fuel woes! Flush the tank and then refill with lead pellets to compensate for the weight reduction by turfing the diesel engine! Problem solved! :-)

[reed1v]

If its an intact black iron tank, leave it alone and add a polishing unit to the tank. Dirty fuel is everywhere and polishing is the best, and cheapest way to go. If you go cutting up your tank, you will find it will not help much. Don't need to clean the scum off side of tank(s). Agitation and polishing will clean that up. Add a biocide to kill off the scum and let the polishing take the stuff out of solution.

[unclemack]

Not sure which of your threads to post this in, sorry for your problems.

Apparently there's a Dick Vosbury posts on Boatdiesel.com forum who's expert on VP's. I'm not a member, he was recommended somewhere else.

I didn't see whether you had checked the condition of the spin-on filter or not?

If you haven't thrown your engine overboard yet there might still be a couple of things you could try cheaply - but I get the feeling you're sick of it and that's fair enough.

[Terra Nova]

Because of the tank's poor accessibility, I think cutting into the side is the right approach. But I would avoid adding any internal coatings. Adding a new day tank is a very good idea. This one should have a convenient sump and drain at the bottom, and sufficient clean-outs at the top (preferably). Fuel from the main tank can be filtered at transfer.

[reed1v]

If the block is good, most diesels can be "easily" rebuilt, assuming you have the tools. Still would advise against cutting into good tanks.

[oceanbug]

I'm an old steel builder in NSW. Few easy fix come to mind as long as it is suitable. What is suitable can only be determined after a chat. sea3deep@yahoo.com if you want to chat.

[Rustic Charm]

Originally Posted by grjfield

Looks like a good opportunity to switch to electric and say goodbye to diesel fuel woes! Flush the tank and then refill with lead pellets to compensate for the weight reduction by turfing the diesel engine! Problem solved! :-)

Can't afford the $27000 I was advised last year for electric, nor the sense in it when the generator would be on way too much of the time.

Most people who need to do the miles conclude electric is simply no where near an option yet.

[Rustic Charm]

Originally Posted by reed1v

If its an intact black iron tank, leave it alone and add a polishing unit to the tank. Dirty fuel is everywhere and polishing is the best, and cheapest way to go. If you go cutting up your tank, you will find it will not help much. Don't need to clean the scum off side of tank(s). Agitation and polishing will clean that up. Add a biocide to kill off the scum and let the polishing take the stuff out of solution.

I added a fuel polisher and was using Fuel Right from last year. The fuel Right did a marverlous job. But, I think the inside of the tank was simply way too far gone to make a huge difference.

The problem with my fuel polisher is that I wrongly designed it so that it can only operate when the engine is off. Which means I didn't use it anywhere near enough.

However, on this trip, with CF advice, I don't think a fuel polisher would have saved me anyway as it sounds like oil in my fuel added to my woes. Not sure why the mechanic didn't recognise the blackness as being oil though.

[Ironman162]

What a nasty problem!
I had similar issues but was able to replace the two petrol tanks with stainless tanks. Not cheap!
I found the baffles were plum in the way and the job just got out of hand. Mind you replacement has its challenges too but in the end we got two new tanks in and haven't looked back since.
My boat runs off petrol of course so cutting and welding was not an option. It had only a tiny cleaning hatch that bolts down.

So my vote is for decent new tank if at all possible. I find enough other things needs a hand....