diesel Fuel Tank Sealer

[andy]

Hi I have removed my diesel tank ot clean it from 20 years of crap in the bottom and have found 2 pin holes is there any way of fixing it .As buying a new one is out of my reach at the moment. Thanks Andy

[MBA Marine]

If its a steel tank then weld it, alloy tank weld it, if its a plastic tank then see if it can be welded (there is a theme here). now you have removed the sludge it will weap from those holes, you might wish you had left it in!!

[Mowjo]

Mark or one of the other could advise you better maybe, but personally I'd hang on and get a new tank, if you have pinholes it means it's on its last legs anyway, and having a repair done could end up making it worse if there isn't a good thickness of metal to weald to, so you may end up paying for the repair and a new tank, plus there's a risk you could have it repaired only for it to dump all the Diesel in your bilge if it goes again,

 

Frank,,,

[C.Ricko]

you can't save money here, if you want the boat not to smell of diesel and you want to keep it then you had best get a new tank...

perhaps if you are lucky you could find a 2nd hand jobbie which may not matter if it were  on the small side or a standard plastic tank may be an option...

 

I should think that by the time you find someone to weld it you could have done something else, normally if a tank has a hole in it it will soon have a few more, also due to the tank being thin you will probably be chasing the hole trying to fix it.

[andy]

Thanks clive . Don't suppose you have a good 2nd hand one for one of your x higher boat ( norfolk gem 2 ) thanks Andy

[Oddfellow]

Wise words from most there (Mark, what are you thinking?).

 

Normally, I am all for trying to fix something rather than replace, but if a steel diesel tank starts to leak, it's had it. Sure, you can patch it up, but it will go again, and they are rarely in accessible places and just what do you do with 80 litres of diesel when it springs a new leak and the tank's half full?

 

Having it leach into your bilges will cause long lasting odours, if the tank sits onor above floorboards, it will permeate the wood too. There are just too many negatatives to skimp on this. PLUS, imagine the next BSS examiner findiing a leak and failing it?

 

We can have Stainless Steel tanks made at very competitive prices or, as suggested, there are a number of off-the-shelf plastic alternatives.

[JawsOrca]

Hi Andy,

 

You can get a rubber tank sealer which is used in classic cars (and aviation I think):

 

http://www.frost.co.uk/por15-fuel-tank-sealers.html

 

This one states petrol tanks so I assume diesel will be ok (although you may want to check).

 

But as above, it maybe wiser and easier to replace the tank. We brought our new tank yesterday for just shy of £100 for an 80 litres plastic tank so they aren't overly expensive. I do have a little collection of tanks in the garage which need to go I think theres a brand new 100litre and you can grab for like £60.  (I've got a stainless (120l i think) which you can have but it could so with the seams welding up as whoever made it couldn't weld). Message me if interested.

 

[Mowjo]

Andy! if your not interested in Alans, it might be worth having a word with Jon at Wayford, he's a member here 650xs, knowing Jon if he dosn't have one he will know someone that has or won't charge you an arm and a leg to make you one,,

 

Frank,,,,

[C.Ricko]

I doubt we would have one now, we have a big clean up a couple of years ago.. I will have a dig about if I get the chance,..

 

We get our tanks from Marine weld, let me know if you want us to look at it for you.

[clive]

Some years back I repaired a petrol tank by obtaining a couple of litres of fibreglass resin with hardener and after thoughrly cleaning the tank by taking of all covers vents etc and leaving for a day or two to allow any vapours to go I then mixed the resin with the hardener poured it into the tank and turned the tank round and round until every where inside was well covered then laid it to one side for a week or two and also bitumen the outside when re fitted it worked perfect for the three years that I owned the car up to selling hope it helps.

 

Clive.

[Mowjo]

Clive! I've seen that done in the past, but I'm sure I read somewhere that the new fuels contain Ethanol  and they can affect the fibreglass/resin

 

Frank,,,

[Mowjo]

Just found this bit and the last bit just reminded me that it was the addition of Ethanol in the new fuel that killed the fuel pump seals on my old 1.5 BMC,,,

 

•  Ethanol can break down resins and fillers in fiberglass gas tanks, causing them to leak.
•  Resins leached from fiberglass tanks can go through the fuel system, sticking to valves and other internal engine parts. These deposits have caused bent pushrods and have clogged intake valves.
•  The alcohol attracts water, leading to increased corrosion in metal gas tanks.
•  Water in the fuel affects the octane and leads to knocking and decreased performance.
•  Ethanol acts as an efficient solvent, gradually cleaning out the accumulated gunk in fuel tanks and lines, and clogging carburetors.
•  Certain rubber gaskets and fuel lines are weakened by ethanol.

[Oddfellow]

I thought you had your own stainless fabrication, Clive. 

 

Marine Weld, incidentally, is up for sale.

 

I feel sure I can beat any Marine Weld price. 

[C.Ricko]

nope, cheaper to outsource, we have a good relationship with Phil, 

 

I don't think putting that kind of info in public is too smart, it is probably a rumour but doubt the staff would like to find out like this.. 

Phil is away for 3 weeks so would not even be able to deal with this put out here.. 

[andy]

Hi thanks for all your help. I am going to try what JawsOrca found just for this year and get a nice new one next winter . It should be okay for this season . Thanks again Andy

[Oddfellow]

nope, cheaper to outsource, we have a good relationship with Phil, 

 

I don't think putting that kind of info in public is too smart, it is probably a rumour but doubt the staff would like to find out like this.. 

Phil is away for 3 weeks so would not even be able to deal with this put out here.. 

 

Sorry, I found it whilst looking on businesses for sale web sites so reasonably assumed it was public knowledge. 

[LondonRascal]

This thread has made me curious. 

 

I assume that Stainless Steel tanks cost more because Stainless Steel as a material to buy costs more  than hot dipped galvanised steel and is harder to weld?

 

I know why people in the marine industry prefer quality Stainless Steel - it's longevity, but one has to wonder IF other forms of tank material cost less to fabricate does it really matter in the long run?

 

If you have a boat from the 1970's/1980's and its tank is now failing its lasted a good while. A replacement that might last 30 odd years before it too begins to fail (if cheaper to have made at the outset) because it is not Stainless Steel does not seem such a bad idea.

 

In other words I personally would not be too bothered about what the state of the tank in the boat might be in 2045 because I would be 65 years old and the boat by then at least that old too and be a host of other issues to contend with than a rusty fuel tank.

[MBA Marine]

Robin,

Although a mild steel tank will last a long time it does corrode on the inside and more crud builds up on the inside that one hopes gets caught in the fuel filters, S/S is far more resistant.

Also weight is a factor, S/S tanks made from 1.5mm maybe 2mm steel and Mild steel tank 3-4mm, is mild steel cheaper when you are using twice as much?

Further to that there is the extra process of galvanizing.

[Oddfellow]

The actual cost difference between mild and stainless isn't huge anyway these days. 

 

But you also need to consider that modern diesel with its additives is more prone to attracting moisture than before. 

 

Many old tanks (and far fewer modern ones I have seen) have an old sump collection point in the bottom with a drain off, but I'll bet you that 90% of boat owners with such a tank don't drain off excess water from it regularly. 

[andy]

Thanks for all your information . I have welded it, new bottom and 6" up the sides and I also haven't put POR15 Fuel Car Tank Repair Sealer in it . No leaks in and working happy days