fuel tanks on marine trader 40'

[paulga]

This week I saw a marine trader 40' sundeck model from mid 1980s.
it has been maintained well despite some leaky stains that are commonly seen in this category.

my concerns are

1. water tank, holding tank and fuel tanks are not visible in the engine room. With the original water tank installed under the aft cabin floor (behind the aft wall of the ER), it is not possible to visually check its condition, and it surely is a heavy project if the water tank ever needs service or replacement.

2. the fuel tanks (original steel) are located on the two sides of ER, behind walls. I didn't find inspection windows to check the condition on the top of tanks if there is rust. Again it would be a big job to service or replace the fuel tanks - e.g. gunks deposits on tank bottom needs cleaning, or clogging issue - I guess it may involve cutting the salon floor open

Please let me know if my concerns are reasonable or if I have missed anything

 

[tiltrider1]

It is a 40 year old boat. This is a reduction in your odds of good tanks. Is the boat in need of TLC? This would further reduce your odds of good tanks.

Finally, if you won the leaky tank award of being required to pay $10,000 to replace a tank, could you write the check? If you can then proceed. If you can’t then you would be living above your means.

I personally won the award on a 40 year old Uniflite. I wrote the check and moved on. I have no regrets about owning that boat. I did make sure that my current boat had accessible tanks as I was unwilling to take a chance of ever winning the award again. Guess what, I won the award a second time but this time it was very easy to pull and repair the tank.

Tank failure is rare but non existent. I am apparently special for winning twice.

 

[paulga]

the quote to replace a pair of tanks on Grand Banks 42 is $35k, so $10k is probably not going to cut it unless the same job on this boat involves fewer hours.

It is a 40 year old boat. This is a reduction in your odds of good tanks. Is the boat in need of TLC? This would further reduce your odds of good tanks.

Finally, if you won the leaky tank award of being required to pay $10,000 to replace a tank, could you write the check? If you can then proceed. If you can’t then you would be living above your means.

I personally won the award on a 40 year old Uniflite. I wrote the check and moved on. I have no regrets about owning that boat. I did make sure that my current boat had accessible tanks as I was unwilling to take a chance of ever winning the award again. Guess what, I won the award a second time but this time it was very easy to pull and repair the tank.

Tank failure is rare but non existent. I am apparently special for winning twice.

 

[Comodave]

On our last boat, a 1987 President, I was going to replace the fuel tanks proactively. I pulled one engine and was getting ready to pull the tank when my back went out. So I gave up on replacing the tank and just cleaned up the engine room and painted, fixed all the electrical issues, rebuilt the shaft log and did misc work. Put the engine back in and hoped the tank wouldn’t ever leak. Covid hit and we decided we needed a faster boat so we sold the President. The new owner told me the fuel tank started leaking the next year.

So in 1980s boats if the tanks have not been replaced you are living on borrowed time. When you buy the boat set aside money to replace the fuel tanks, then don’t spend it on other things. The water tank isn’t as important as the fuel tank because if water starts leaking it is an inconvenience but not a violation of the law like leaking fuel can be if it gets pumped overboard when you aren’t there.

The new owner told me it was going to be around $12K to have the tanks replaced. I was going to spend about $2,200 for each tank and do the replacement myself.

 

[paulga]

I'd also max out the service life of the tanks before having to repair.

if you look at my photos, what approach do you see to pull out the tanks and put new ones in?

On our last boat, a 1987 President, I was going to replace the fuel tanks proactively. I pulled one engine and was getting ready to pull the tank when my back went out. So I gave up on replacing the tank and just cleaned up the engine room and painted, fixed all the electrical issues, rebuilt the shaft log and did misc work. Put the engine back in and hoped the tank wouldn’t ever leak. Covid hit and we decided we needed a faster boat so we sold the President. The new owner told me the fuel tank started leaking the next year.

So in 1980s boats if the tanks have not been replaced you are living on borrowed time. When you buy the boat set aside money to replace the fuel tanks, then don’t spend it on other things. The water tank isn’t as important as the fuel tank because if water starts leaking it is an inconvenience but not a violation of the law like leaking fuel can be if it gets pumped overboard when you aren’t there.

The new owner told me it was going to be around $12K to have the tanks replaced. I was going to spend about $2,200 for each tank and do the replacement myself.

 

[tiltrider1]

First, my $10,000 estimate was for one tank and probably based on an easier job than what you have there.

Most boats run saddle tanks and require the engines to be removed. Those of us who have done this job often gloss over the fact that things like water heaters, generators, batteries, and everything attached to the wall also needs to be removed. Then there is the disassembly of the saloon floor. It’s a big job.

A quote of $35,000 for both tanks dose not surprise me. Just remember, you are buying a 40 year old boat for less than $100,000. A similar new boat is $1,000,000.

Since the average ownership period of a boat is 5-7 years most people take the gamble and Winn but eventually there has to be a looser.

Just recently there was a post by a guy who had to cut out the sides of the boat to R&R his tanks. This can be done as well and might be the solution for the boat you are looking at.

In the end you have to ask yourself just one question “DO I FEEL LUCKY?”

 

[paulga]

Thanks for confirming.
so $10k is the price for only one tank. it aligns with one quote from a comment to this video

First, my $10,000 estimate was for one tank and probably based on an easier job than what you have there.

Most boats run saddle tanks and require the engines to be removed. Those of us who have done this job often gloss over the fact that things like water heaters, generators, batteries, and everything attached to the wall also needs to be removed. Then there is the disassembly of the saloon floor. It’s a big job.

A quote of $35,000 for both tanks dose not surprise me. Just remember, you are buying a 40 year old boat for less than $100,000. A similar new boat is $1,000,000.

Since the average ownership period of a boat is 5-7 years most people take the gamble and Winn but eventually there has to be a looser.

Just recently there was a post by a guy who had to cut out the sides of the boat to R&R his tanks. This can be done as well and might be the solution for the boat you are looking at.

In the end you have to ask yourself just one question “DO I FEEL LUCKY?”

 

[mvweebles]

I had my two steel saddle tanks replaced in fiberglass 3 years ago in Mexico. I don't know exactly what my capacity was before but I think it was 225-240 each side. I am pretty sure I lost no more than about 20g per side - one tank per side has become two tanks per side.

Tank fabrication was $6k in Mexico. Engine removal and reinstall was $800. But there was also a bunch of valves, hoses, etc. Plus I redesigned my fuel system at same time. Best guess I'm into the tanks $12k, but a much better setup than what I had. I used fiberglass fittings made for oil field fracking and there are no fastener penetrations, even for the clean out ports. The fittings, crossover valves, hoses, etc. alone were $1500. I also had some guards fabricated to protect the valves from accidental impact.

Even at US prices, $45k sounds high. For skilled workers, getting the engines out in a day is totally doable (or doing one side at a time by stacking the engines temporarily). Cutting the old tanks out in two days is doable too.

That said, replacing tanks can be a "scope creep" black hole. New fuel system, polishing system, might as well paint the engine room, new sound insulation, redo some electrics, new water heater, etc. Tanks are perhaps the greatest potential scope creep potential on boats like these. Unless you're totally in love and infatuated, I wouldn't go there. Just my opinion.

Peter

 

[fryedaze]

If you have the time and patience you may be able to do it yourself. I am a cheap sob and the only reason I let go of a dollar is to get a tighter grip on it. I replaced a 175 gal tank with two 77 gal tanks. I took a day to remove interference and a day to cut the tank up and remove it. That is after countless hours researching and planning. All in $2206.00 US. It's here on the forum. I am going to do the port side next month. I suspect the tank cost will double.

https://www.trawlerforum.com/forums/showthread.php?t=39628

Dave

 

[tiltrider1]

Scope creep! That’s an understatement. Engine is out, now it’s easy to work on. Generator is out let’s really inspect it. Oh, we had to cut two mahogany beams that were 2x5” and 12.5 feet long, were do you find that.

Look at all the room now available. Should I update the engine exhaust? What about adding a fuel manifold. Should I relocate the Raycor now that I have been forced to remove it? Good time to fix all that inaccessible wiring and plumbing. The list goes on.

Yes leaky fuel tanks is a sore subject.

 

[Comodave]

I built a crane in the salon and lifted the port engine and stacked it over the starboard engine after reinforcing the deck. It took 3 of us above 2 hours to lift the engine and get it set on some temporary stringers above the starboard engine. It took about 2 hours to reinstall the engine when I was ready. I had it out for about 6 weeks while I did a bunch of misc work. But with my back causing problems I couldn’t work for very long each day. If I had been able to do the tank it would have been less than $3K including the tank and misc hardware. I spent about $1,200 building the crane though.

 

[Comodave]

Here are some photos of the engine crane and being pulled. Some are from the port engine and some are from the starboard engine.

 

[PM]

This is a subject that gets discussed endlessly on T.F. The long and short of it is that the tanks will fail soon, no question.

If the tanks have not been replaced you can plan on it happening on your watch. The present owner knows this and better make a price accomodation on the sale price.

pete

 

[paulga]

the boat was already sold to someone who made a lightening offer.

the tanks being inaccessible was the reason I was reluctant to offer a bid. otherwise it's a well maintained example of a single diesel model.

This is a subject that gets discussed endlessly on T.F. The long and short of it is that the tanks will fail soon, no question.

If the tanks have not been replaced you can plan on it happening on your watch. The present owner knows this and better make a price accomodation on the sale price.

pete

 

[Jeff F]

... I did make sure that my current boat had accessible tanks as I was unwilling to take a chance of ever winning the award again. Guess what, I won the award a second time but this time it was very easy to pull and repair the tank.

Tank failure is rare but non existent. I am apparently special for winning twice.

I'd say you're just ahead of the curve. There is a huge cohort of boats built in the 1980s that are just now coming due for tank replacement.

Like you, accessibility to tanks and machinery was high on my list when I went looking for my current boat. Everything is going to break. Plan accordingly.

 

[Don L]

isn"t there way to NDT inspect tanks?

 

[paulga]

according to the youtube video, a good survey will assess the tank condition and give an estimate of its life expectancy. This is an add on item that adds ~$1k to the survey budget.

isn"t there way to NDT inspect tanks?

 

[Comodave]

according to the youtube video, a good survey will assess the tank condition and give an estimate of its life expectancy. This is an add on item that adds ~$1k to the survey budget.

In a video maybe, but in real life on some tanks there isn’t any way to inspect the tanks. And without inspection ports there isn’t any way to see inside.

 

[tiltrider1]

We are discussing 40 year old boats. At some point the engines and tanks will have reached end of life. We just don’t have any experience to say when exactly that will be. I don’t really know any pleasure boats that have found the end of life on eNgines. Commercial boats yes, 25,000 to 30,000 hours. Will pleasure boats make it that long? I doubt it but possible. What is end of life for fuel tanks? Don’t know but we are seeing failures around the 30 year mark but most might go 50 or more hard to know but time will tell.

We are seeing washers and dryers on boats giving up between 30 and 40 years so if you buy a 35 year old boat with a washer and dryer onboard that is original, expect it to die on your watch. Look through yacht world, half of the mid 80’s boats show new modern washers and half show original equipment. Very good indication that 30-40 years is all a W/D has in it even with light usage.

Boating is not cheap and if you enter on a shoe string budget you better be like Comodave and do everything your self.

 

[paulga]

I'm handy on entry level mechanics, e.g. I feel comfortable replacing a W/D, the cost is $1k and i'm familiar with the connections. I can also change oil and filters, like most ppl can. But things beyond the entry level, e.g. cleaning or replacing the fuel tanks, requires more resource and assistance, would have to be performed by contractors with a potential cost ~$40k+. this may solve the tanks good for 20 - 30 years, but it's as a big toll to most people as it held me back.

We are discussing 40 year old boats. At some point the engines and tanks will have reached end of life. We just don’t have any experience to say when exactly that will be. I don’t really know any pleasure boats that have found the end of life on eNgines. Commercial boats yes, 25,000 to 30,000 hours. Will pleasure boats make it that long? I doubt it but possible. What is end of life for fuel tanks? Don’t know but we are seeing failures around the 30 year mark but most might go 50 or more hard to know but time will tell.

We are seeing washers and dryers on boats giving up between 30 and 40 years so if you buy a 35 year old boat with a washer and dryer onboard that is original, expect it to die on your watch. Look through yacht world, half of the mid 80’s boats show new modern washers and half show original equipment. Very good indication that 30-40 years is all a W/D has in it even with light usage.

Boating is not cheap and if you enter on a shoe string budget you better be like Comodave and do everything your self.

 

[Comodave]

Yes, fuel tanks are a crap shoot. You may get lucky or not. If you buy an older trawler then check the fuel tanks as best you can. Then plan on replacing them and if you don’t have to, you lucked out. Even with a really good inspection of the tanks that is no guarantee that they won’t leak. Ah, well…

 

[fryedaze]

I'm handy on entry level mechanics, e.g. I feel comfortable replacing a W/D, the cost is $1k and i'm familiar with the connections. I can also change oil and filters, like most ppl can. But things beyond the entry level, e.g. cleaning or replacing the fuel tanks, requires more resource and assistance, would have to be performed by contractors with a potential cost ~$40k+. this may solve the tanks good for 20 - 30 years, but it's as a big toll to most people as it held me back.

This is not a scary job. Spend some time thinking it through. Remove interferences and remember how to put them back. Get a bunch of Diablo carbide tipped sawsall blades. Cut the tank up in pieces you can get out of the boat. Measure the max tank size you can get into the boat. It may take two or three tanks tied together. Grand Banks take 3; stacked on top of each other. Mine was two side by side. Make a drawing of the shape and connections you want. Provide to a tank fabricator. Get them made . Put them back in. Save about $10k in inflated labor cost.
Here is the crap a yard will pull.
2 guys 8 hrs to remove interference $100/hr=$$1600. I did it alone in 8 hrs. 2 guys 16 hrs to remove the tank. $3200. I did it alone in 8 hrs. Install 2 guys 16 hrs $3200 hrs. I did it in 8 hrs. Cost of tanks $3500. In 2018 it cost $1800.
Fear of the unknown let's the yard drive the estimate way up.
It's not rocket science.

 

[Comodave]

This is not a scary job. Spend some time thinking it through. Remove interferences and remember how to put them back. Get a bunch of Diablo carbide tipped sawsall blades. Cut the tank up in pieces you can get out of the boat. Measure the max tank size you can get into the boat. It may take two or three tanks tied together. Grand Banks take 3; stacked on top of each other. Mine was two side by side. Make a drawing of the shape and connections you want. Provide to a tank fabricator. Get them made . Put them back in. Save about $10k in inflated labor cost.
Here is the crap a yard will pull.
2 guys 8 hrs to remove interference $100/hr=$$1600. I did it alone in 8 hrs. 2 guys 16 hrs to remove the tank. $3200. I did it alone in 8 hrs. Install 2 guys 16 hrs $3200 hrs. I did it in 8 hrs. Cost of tanks $3500. In 2018 it cost $1800.
Fear of the unknown let's the yard drive the estimate way up.
It's not rocket science.

Pretty much everything is scary the first time but when you get into it, it usually isn’t so bad. Agree on making a plan. One thing to do is make a full size mockup of the tank you think will fit out of luan or even cardboard and make sure it will fit through the doors and past any other obstacles.

 

[paulga]

these numbers are encouraging, but at the first step, you still have to lift the engine and generator out of the way even if it is a single engine conf. I have no time to reinvent Comodave's winch system. I'd also first recognize most of the parts and hoses then feel ready to work on anything.

when designing the new tanks, you also need design a framework that stacks and fixes the tanklets to the hull, as well as the plumbing system b/t the tanks, connections for some sensors, I'm lacking the engineering background to draw the schematics.

This is not a scary job. Spend some time thinking it through. Remove interferences and remember how to put them back. Get a bunch of Diablo carbide tipped sawsall blades. Cut the tank up in pieces you can get out of the boat. Measure the max tank size you can get into the boat. It may take two or three tanks tied together. Grand Banks take 3; stacked on top of each other. Mine was two side by side. Make a drawing of the shape and connections you want. Provide to a tank fabricator. Get them made . Put them back in. Save about $10k in inflated labor cost.
Here is the crap a yard will pull.
2 guys 8 hrs to remove interference $100/hr=$$1600. I did it alone in 8 hrs. 2 guys 16 hrs to remove the tank. $3200. I did it alone in 8 hrs. Install 2 guys 16 hrs $3200 hrs. I did it in 8 hrs. Cost of tanks $3500. In 2018 it cost $1800.
Fear of the unknown let's the yard drive the estimate way up.
It's not rocket science.

 

[paulga]

I was wrong. In a single engine conf, you may not need remove the engine to replace the fuel tanks. It may not help a lot with the $ quote though.

Here is an example the couple got it done on a Monk 36. The man did all the physical work, the wife worked on documentation. She documented how they built the proto tanks from cardboards

https://pacificsailors.com/2019/05/diesel-tank-replacement.html

With the long list of the "now that we re here" projects, it is a reasonable DIY job.

these numbers are encouraging, but at the first step, you still have to lift the engine and generator out of the way even if it is a single engine conf. I have no time to reinvent Comodave's winch system. I'd also first recognize most of the parts and hoses then feel ready to work on anything.

when designing the new tanks, you also need design a framework that stacks and fixes the tanklets to the hull, as well as the plumbing system b/t the tanks, connections for some sensors, I'm lacking the engineering background to draw the schematics.

 

[Comodave]

I think everyone was thinking that the boat had twin engines, I know that I was. Single engine would probably be a piece of cake.

 

[mvweebles]

I think everyone was thinking that the boat had twin engines, I know that I was. Single engine would probably be a piece of cake.

On my single engine boat, engine had to be removed unless I wanted to significantly reduce tankage.

As to "piece of cake," I'll repost the picture from OP showing one side of what's attached to the tank bulkhead. Can of worms.

If kept dry - inside and out, a steel tank will last indefinitely. Unfortunately, that's very tough to do, especially with teak decks. One thing I wish I had done differently on my refit was to move the side-deck diesel fills to a vertical sidewall to avoid common water washing over the full neck. It's a lot of faith to put in a small o-ring. Fortunately my tanks are now fiberglass.

Peter

 

[paulga]

In the Monk 36 example, apparently both the door and engine room with engine in place allow for a half size tank to come through.

The boat had original fiberglass deck which may have kept the tank dry. It is however not a guarantee so I would still like to check for rust. Then I found both fuel tanks are off limit to my view or touch.

Probably with single engine setup, tank replacement would require less money by contractors like American Tank?

On my single engine boat, engine had to be removed unless I wanted to significantly reduce tankage.

As to "piece of cake," I'll repost the picture from OP showing one side of what's attached to the tank bulkhead. Can of worms.

If kept dry - inside and out, a steel tank will last indefinitely. Unfortunately, that's very tough to do, especially with teak decks. One thing I wish I had done differently on my refit was to move the side-deck diesel fills to a vertical sidewall to avoid common water washing over the full neck. It's a lot of faith to put in a small o-ring. Fortunately my tanks are now fiberglass.

Peter
View attachment 140001

 

[mvweebles]

In the Monk 36 example, apparently both the door and engine room with engine in place allow for a half size tank to come through.

The boat had original fiberglass deck which may have kept the tank dry. It is however not a guarantee so I would still like to check for rust. Then I found both fuel tanks are off limit to my view or touch.

Probably with single engine setup, tank replacement would require less money by contractors like American Tank?

First, the engine room looks nicely organized. However, there is a LOT of stuff that needs to be un-installed before the tanks are even attempted. And then it has to be re-assembled. Could be easy, maybe not.

There's a decent chance the tanks are fine. Forums like these get a lot of "OMG - leaking fuel tank!!!!" stories, but I suspect its because no one writes in with "OMG - my fuel tank doesn't leak!!!" But there is no way to know. Could leak tomorrow. Could outlive us all. But I sure wouldn't do a prophylactic swap.

Folks on this forum are really scared to pull an engine. I wouldnt do it myself, but having watched people who do it all the time, engine is out in under a day with two guys working it. It's pretty straightforward if you've done it before and you have the equipment. Likely cheaper than making heroic measures to squeeze reduced-size tanks past the engine.

You budget has probably pushed you towards a 40+ year old Taiwan Trawler. Given the engine room looks orderly, I assume the boat in general is in decent shape. If there are no signs of tank leakage, and you really want a survey credit just-in-case, well, you should re-think your purchase strategy. Older trawlers are not for you unless you find one with fiberglass tanks; or one that had the tanks recently replaced.

Good luck with whatever you decide.

Peter

 

[Cigatoo]

I watched them open up the hull of a vintage 1980’s trawler (Marine Trader?) and replace diesel tanks last summer. I really wish I had taken pictures and documented the process. They made it look easy. Very little disruption of the interior and engine room. They cut out a panel on each side of the hull, removed the tanks, install new tanks, and re glassed in the panels. The tank work is easily a DIY project if you have a good glass guy to open and close the “wound” on each side.