Replacing the Diesel Tank in our 1988 Westerly Konsort by Otto Hollerwöger

The Problem

When we travelled to the East of England in January 2020 to look at the “Periplus” (now: “pepperbird”) for sale, we also engaged a local surveyor to help us make a decision. His report was positive enough that we finally decided to buy. However, there were a few points that the surveyor noted as “recommendations” in his report. One of them concerned the diesel tank: “It is Recommended that the corrosion at the starboard side aft lower corner of the fuel tank be cleaned of corrosion material and painted.”

Then came the first big lockdown, so it wasn’t until August that we were able to bring the boat to the Netherlands, where it was reasonably accessible from our living place in Vienna. I talked to friends and experts about the matter, and the assessments were very different: Matthias, certainly the most knowledgeable of all my friends, said that there was probably a lot of solid material left, so that repairing this one spot would probably still make sense. He also realised that the corner in question was resting on the wooden board due to the slight bend in the mounting plate and that the vibrations of the engine would probably have caused the paint on the tank to chip. We loosened the nearest fastening screw and placed a spacer board underneath, which then left the corner free, and the vibrations could not cause any further damage. What we couldn’t see, however (not even with an endoscope), was whether there might have been other places that had also started to corrode. And even if we had seen them, there was nothing we could have done without removing the tank. At about the same time, I read about a Fulmar whose tank had rusted through and leaked from the inside – the worst-case scenario! It was clear that after thirty years of operation, so much sludge would have accumulated at the bottom of the tank that it would not have been possible to examine it even with an endoscope. That was the point at which I began to look at the idea of a new tank.

Various Considerations

I saw two options for this, which involved more or less work and money. I could have a new stainless-steel tank made that would be an exact replica of the existing one and simply replace it. Or I could find a new prefabricated tank that would fit somewhere in the stern of the boat. The second option would be cheaper than the first, but all the diesel lines from the tank opening and to the engine would have to be redone, which would have cost more time and money. Initial enquiries with Viennese locksmiths were very discouraging. The cost estimates I received were between €1,500.00 and €1,800.00. I had not expected that much. On the other hand, I couldn’t find a finished tank, plastic or steel, that would have fit where the old tank was. Beginning with the tube from the tank tap on deck to the feed line to the motor and to the return line from the engine to the tank, all the lines would have to be redone. Even if I had been prepared to pay this expense, it was impossible to estimate how long the work on the tank would keep us busy on site. And I don’t live near our boat (yet)!

The Solution

The way out was found when I talked to Peter, my brother-in-law, who is a trained mechanic (even though he only does this job as a “hobby”), about the matter. He had an acquaintance in his area who does stainless steel work as also a “hobby”, and he wanted to talk to him about whether he could make such a tank. He said I shouldn’t worry about the price; the guy owed him and would do it for him cheaply. Although I didn’t want to order something I didn’t know the price of, this seemed to me to be the most sustainable and, all in all, the cheapest solution, even though I kept thinking that the easiest thing to do would be to sand off the rust thoroughly, treat the metal with rust converter and then paint it, in other words, to follow the expert’s recommendation exactly. But then I remembered the tank of the Fulmar, which had rusted through from the inside…

In the end, we thought it would be best to find a sustainable solution that would be as close as possible to the original condition of the boat – that means rebuilding and replacing the tank.

On the Wiki of the Westerly Owners Association, I found a sketch of the tank that pretty much matched the dimensions I had measured, and I read in one of the many forum-discussions on the subject that removing and installing it on a Konsort was very easy to do. So, at the end of our 2021 autumn cruise, the time had come: after craning, we emptied the remaining diesel as much as possible with a hose pump and then Matthias climbed into the cockpit locker. In no time at all he had loosened all the pipes from the tank and removed all three fastening bolts. Now we could push the container forward and with a little turning and pushing it was lifted out into the cockpit. When we tried to empty the diesel sump, we unfortunately broke off the seized valve. We then rinsed the whole thing out, disposed of all the contaminated liquids accordingly and then packed the tank in lots of plastic foil to make it odour-proof and transported it to in-law Peter’s in Upper Austria.

The Execution

Over the following winter, the old tank was measured in detail and a construction drawing true to the original was made. According to this, the sheet metal parts were cut out by laser and professionally welded. New valves and hose connections were fitted and at the end of March I received this photo on my mobile phone.

Then there was a discussion about whether the new – stainless-steel – tank should be powder-coated or not. I was against it, because no one would see anything of the device if they didn’t bother to climb into the locker. Peter and his locksmith friend, on the other hand, argued that the salty sea air would dull and stain the steel, which is why it was powder- coated in “anthracite”. As an extra, I was given a pipe and valve that would make it much easier to drain the sump with the help of a larger tap.

In the course of the 2022 spring cruise, the new tank was picked up in Upper Austria and installed before the craning. The installation of the new diesel tank was as problem-free as the removal. The threads were sealed with silicone tape, the tabs for the fastening fitted exactly over the slightly larger drilled holes in the mounting board. The tube for the sump valve was a little too long to fit behind the reinforcement of the P-bracket of the propeller shaft. We simply turned the tube a little to the side and attached a piece of hose to it. It should now be no problem to drain the diesel completely through this pipe, should someone ever find it necessary to clean the sump.

After assembly, we first filled in only about 10 litres of fuel to test whether all connections were tight. They are! There is, however, one difference to the original tank: we made it without the sight tube to indicate the fill level. The old one had become so cloudy anyway that you could only guess how high the diesel was in the tank and you can estimate the consumption of the engine quite well (about 1 litre per hour in normal operation) so there is hardly any danger of suddenly being without fuel. On longer journeys, you have to carry enough spare fuel anyway, because the 67 litres would hardly be enough for longer distances. If necessary, a stick could be inserted through the tank supply line so that at least the filling height above the inlet knee can be determined.

Moral? In the end, we paid €600.00 for the tank and had a few hours of interesting work for the removal and installation. It still works, the old Austrian way of doing business: If you know someone who knows someone, then you get things done without having to bother with such annoying issues as regulations and taxes.