Monk 36 Fuel Tank Replacement

[jacsan]

I'm considering a Monk 36 that recently went on contract and during the survey rust was discovered on top of the fuel tank. According to the owner the surveyor was not concerned about the rust. The buyer backed out of the deal. We all know rust does not go away and only gets worse.
Has anyone replaced the fuel tanks and at what cost?

Thanks in advance.

 

[MVCalypso]

Hi,
For whatever it's worth, here is a thread about how I replaced the tanks in my Island Gypsy during 2022:

Island Gypsy fuel tanks project summary

Hi, I was asked in another thread for pics of the approach I utilized during 2022 to replace the fuel tanks in my 1984 Island Gypsy 36 Europa. Most seem to choose the "cut em out and put multiple smaller tanks in" approach. I choose to take the tanks out thru the sides of the hull. The...

www.trawlerforum.com

Whether you choose the "cut the old ones out then replace with multiple tank 'slices' " or the "take them out thru the hull and replace with new one piece tanks", there is a lot of labor involved and that makes it a significant project cost.

Frankly if a surveyor doesn't think that (anything more than trivial surface) rust on a tank is a NOT serious problem, well, go find a competent surveyor!

 

[Comodave]

If it is a steel, black iron, tank then as the song said”rust never sleeps”. Same thing here. The top rust is probably from a leaking fuel filler. But if it has rust on top it will likely have rust on the bottom. I replaced a steel tank in a previous boat. They custom made a mold and then fiberglassed the tank. We had to cut the back of the cabin out to get the new tank in. It was a big tank, about 560 gallons. It wasn’t cheap.

 

[Andy G]

As we are on the other side of the 'big pond' cost factors may be considerably different from what you could expect to pay. However, this may give you some idea.

Sarawana has twin 120 Lehman's with a 7 KVA generator. She had mild steel tanks that when we bought her some 17 years ago had mild rust issues on the top of the tank. We sorted that out by taking up the teak deck and re glassing. However the damage was done and the rust got worse.

This year we bit the bullet and replaced the tanks. The generator was taken out and the tanks cut up in situ. New poly tanks were made up and installed. Cost for that was AU $40K.

However, that was not the end of it. With the tanks out we inspected the engine room pretty carefully, this being the only time you can access some areas of the ER. We ended up replacing a lot of other items which pushed the costs up by another AU$10K. Plus we did a few other things that had nothing to do with the tanks.

I have no idea of US labour costs etc however over the years on TF it seems we pay more for like on like work, so you may find quotes cheaper than we did. Also, the yard we used was very highly rated, very experienced on working on Island Gypsy boats, and quite old fashioned in their approach to the work. However, I felt quite confident to follow their advice.

Our engine room now looks terrific.

That's our story.

Good luck with yours.

PS. This is not anything to do with the question posted by the OP but with the amount of sludge that came out of the old tanks it was amazing the engines could operate as they did. The old Lehman's may be dinosaurs but they are pretty robust and seem to be able to operate in less than ideal situations.