I'd like to consider doing some cleaning/maintenance on my MkII (model year 2001) fuel tank, and would appreciate some guidance for those of you who have done this before. How do you access the tank? It seems like might be glassed in on top, with only a couple screw-off ports in the port locker. I know that one of the ports covers the on-off valve from the dip tube. Is there a way to remove the dip tube?
Does the tank have any inspection ports installed at the factory? Is there a way to get to them without cutting apart the locker? Is there a side panel in the aft berth that gives any better access? What is the tank made of?
It seems like the fuel fill port is not a straight drop into the tank, so you can't insert a dip stick or pump-out wand into the tank. How else do you empty the tank?
Breakin,
I pulled my tank and cleaned it in 2012 per Ron Hill's Tech Note instructions. Here's a link to a similar discussion. http://c34.org/bbs/index.php/topic,9355.msg69451.html#msg69451 (http://c34.org/bbs/index.php/topic,9355.msg69451.html#msg69451) I have a 1994 Mk 1.5 but I don't think the fuel tank configuration changed much for later builds.
The tank is not glassed in. It's screwed to the shelf accessible by removing the port wall in the aft cabin which comes out very easily (once you've cleared out "the garage").
The suction and return line tubes are threaded into the tank as shown in the picture. The level gauge is bolted in via a small plate.
There are no inspection ports on my tank nor do I think there are ports on any C34 OEM tanks. I seem to recall some owners have added them. A search should show this.
My tank is made of 0.090" thick 5052 Aluminium
The fuel fill is not a straight drop.
The tank can be emptied by pumping it out. Have an appropriate number of 20 litre diesel containers available and disconnect the fuel delivery line after the electric pump and place the hose in the container. For convenience, you will likely want to make up a longer hose.
Pics of my tank In Situ and removed attached.
Hope this helps. It's a fairly easy job.
I'm in hull 1494 (2000). I've never cleaned the fuel tank - not sure if the PO ever did. I'm careful about putting in clean fuel (I've got a funnel with a filter). My Racor does not indicate any sediment. I don't think I am having any issues...engine is running fine (980 hours). Nonetheless, is cleaning/inspection something that should be done periodically?
Geoff,
My tank was clean when I pulled it out. It was 18 years old and to my knowledge, had never been cleaned. Nevertheless, I went through the process because I had already gone to the effort of pulling the tank. I'm glad I did as I no longer lay awake worrying about nasty growth or sediment hiding in the tank waiting to clog my filter and kill my engine at the most inopportune time.
Thanks Dave! May pull it one of these years and do the same. Just wondering if anyone recommends regular inspection.
FWIW, I replace my Racor filter every year. I've never seen even a drop of water in my Racor bowl. But I do see a little bit of brown stuff there occasionally. I'd like everything to be pristine, so now that my tank is down to about 6 gallons in it I am considering draining it to inspect the fuel (or the tank, if there was an inspection port).
I usually fill the tank every winter to avoid "breathing" in the headspace and condensation that comes with it. That has apparently worked well because I don't ever have any water. But there is a little bit of stuff that I'd like to completely eradicate.
If you're way up north you may have a less hostile environment.
Geoffrey,
I think regular inspection would only be for the most anal sailor. However, I think Breakin has a point. I suspect those of us in the north would be at lower risk for growth inside the tank as opposed to those sailors in warm humid conditions for most of the year.
Interesting note. A dear friend with a 1988 C30 cleans his fuel tank on a schedule of every two years. This spring he drained the entire tank and then used a cloth wire tied to a stick to reach inside and actually wiped out the tank wherever he could reach to remove any residue. Pretty thorough eh?..... Well...just a few weeks later at the beginning of our annual cruise he was heading south on the Chesapeake when his motor died.....he sailed/was towed into the marina where three of us descended upon his vessel to help determine the problem (the first problem was there wasn't enough beer aboard...readily solved that one in record time)
As it turned out we found a clog of really gross stuff had worked its way into the pick up tube and had lodged right outside the secondary filter at a 90 degree elbow BEFORE the filter!!! The remedy was to pressurize the tank thru the vent hose with the other end disconnected at the filter. (easily accomplished with a paddle board inflation pump) A nice size glop of pretty ugly stuff plopped out into a paper towel and that and a new fuel pump was all that it took to get him going.
Interesting side note I just remembered. This good friend carries spares...he even had a brand new spare factory fuel pump he'd had aboard for about two years "just in case". The problem was that not only had the original fuel pump failed...but the spare was dead too!!!! (yes...we tested it extensively to come to this determination) We ended up having to get a ride to a local auto parts store to get a temporary diesel fuel pump so they could at least continue on for the week.
Moral of the story, don't clean just the tank, pressurize your lines a bit too and get them cleaned out prior to the secondary filter. Secondly, TEST your spare parts before you stow them. Replacements may not be so readily available and that would have been an ugly end to a fun week!!!
Eric Wengstrom
1988 C34 "Ohana"
Guys : I got the idea of cleaning my fuel tank came from my experience in aircraft maintenance!! In Vietnam (especially) the UH-1 (Huey) on it's 10th PE (Parodic Enspection every 100 hour of flying) called for removing the fuel tanks (self sealing blatters) and turning them inside out and cleaning them. Can't tell you how many gallons of fuel is used in 1000hrs, but it's a bunch!! It didn't take that long in days to accumulate 1000hrs either.
Can't remember, but I think I first cleaned my tank at the about 10/12 years. I dutifully used Biobore and Waterzorb, but the tank still needed to be cleaned!!
A few thoughts
Quote from: Dave Spencer on October 01, 2019, 12:25:06 PM
Geoffrey,
I think regular inspection would only be for the most anal sailor. However, I think Breakin has a point. I suspect those of us in the north would be at lower risk for growth inside the tank as opposed to those sailors in warm humid conditions for most of the year.
Boats in the "North" can experience large, quick swings in temperature which cause condensation within fuel tanks. Our 34's have relatively small tanks which are easy to remove. So....Every ~5yrs. I sleep better at night knowing I don't owe anybody money.
There are lots of variables. Here's some food for thought from a well regarded authority and a frequent contributor to this site.
YBYC
https://www.pbase.com/mainecruising/fuel_tankt_condensation (https://www.pbase.com/mainecruising/fuel_tankt_condensation)
The folks here with clean tanks are fortunate. If you've owned your boat for the majority of its' life, and practiced a good fuel regimen you may be fortunate too.
My boat was 28 years old when I bought her, and my fuel tank experience has been quite different. With the baffle in the center, I didn't see a way to inspect the inside of the fuel tank without access plates. I cut holes in the top of mine and installed two 8" access plates. The photo below is what I pulled out of my 1987 fuel tank earlier this year. (after 4 years, I did not see any contaminates in the Racor). After cleaning the tank, it unforunately began to leak so I replaced the whole tank with a more robust design which included relocation of the fuel fill hose, thru bolting the forward end of the tank to the mounting platform, and adding an aft hold down screw. I also changed the gate valve to a diesel compatable ball valve, added a second shut-off valve at the head door opening so I can reach it, and replaced the hoses to the Racor. See second photo.
Wow, hard to believe that you had that much in your tank and didn't see anything come through the Racor.
I had seen MaineSail's blog on this topic before, but had forgotten how powerful it was. I might try draining my tank at layup this year and storing the fuel in jerry cans, then decanting/filtering back in next year. Previously I would run down my fuel through the season and top off before winter layup to avoid condensation. But that means my fuel is already 6 months old when I launch. So, just to try something different, I might leave the tank empty and top off with fresh fuel at the start of the season.
About 1/16" thick hard layer across the entire bottom of the tank. Soaked it for days with a 1 to 1 mixture of Simple Green and water. Then used plastic scraper to peel it off the bottom. Whole process was just under 2 weeks. Then it leaked. :shock:
Quote from: Jon W on October 01, 2019, 07:46:32 PM
About 1/16" thick hard layer across the entire bottom of the tank. Soaked it for days with a 1 to 1 mixture of Simple Green and water. Then used plastic scraper to peel it off the bottom. Whole process was just under 2 weeks. Then it leaked. :shock:
Reminds me of people who have old cars and switch from dino oil to synthetic. The synthetic oils dissolves all the gunk that was plugging the cracking seals, and ends up leaking.
If anyone is interested, here is what I do.
In the early spring when I'm eager to ready Shamrock but it's too cold to do much. I remove the fuel gage cover and take a fuel sample from the bottom of the tank into a clear mason jar. FWIW wish it was a straight shot from the fuel fill to tank. It's been sitting all winter so anything that's going to settle has. Has always been clean. If there were anything settled out then I'd take action.
That's good enough for me not to worry about a dirty fuel tank.
Jim
Jim : If you had the MK l fuel pump set up - you could just disconnect the inlet hose to the Racor and turn on the key switch and let the electric fuel pump pump a bit of that bottom fuel into a Mason jar and you could look for the any junk /water in the bottom of the jar! Very evident!!
The first preflight of the Day always drained fuel from the tanks to look for condensation!!
A thought :thumb:
Quoteyou could just disconnect the inlet hose to the Racor and turn on the key switch and let the electric fuel pump pump a bit of that bottom fuel into a Mason jar
I don't believe the fuel pick-up tube goes to the very bottom of the tank.
Jim : The pickup tube goes down to about 2 inches above the bottom of the tank. Then attached to the pickup tube is a piece of 3/8" flexible fuel line about 4" long. That flex line is what lays on the bottom of the fuel tank.
It's made like that just so it picks up fuel from the very bottom!!
A few thoughts :thumb:
Jim : With a MKII you can do the same!!
Just disconnect the inlet fuel hose to the Racor. Put that hose in to a mason jar and turn on the key switch (battery power ON) and go to the glow plug (spring loaded) position for 45+? seconds. Enough to get all of the fuel out of the line and let the "old bottom" fuel fill and pump into the mason jar!
A thought :clap
Quote from: Ron Hill on October 06, 2019, 04:39:40 PM
Jim : With a MKII you can do the same!!
Just disconnect the inlet fuel hose to the Racor. Put that hose in to a mason jar and turn on the key switch (battery power ON) and go to the glow plug (spring loaded) position for 45+? seconds. Enough to get all of the fuel out of the line and let the "old bottom" fuel fill and pump into the mason jar!
A thought :clap
I'm coming back to this topic after a couple of months of working on other stuff. My fuel tank is down to about 5 gallons (based on the fuel gauge calibration that I posted elsewhere), and I am preparing to drain it for the winter like Maine Sail recommends. But I am a bit confused by your recommendation here. Isn't the lift pump
downstream from the Racor filter? If so, disconnecting the fuel inlet to the Racor should allow the tank to gravity drain into the Mason jar without the pump running. A Mason jar would be fine for taking a sample (though I'm not sure why this sample would look any different from what's in the plastic water separation cup). In my case, I'll need something a little larger than a Mason jar to drain the whole tank.
It's been a little while since I looked over the boat, but I recall seeing something that indicated it would be difficult to for me to remove the tubing to the Racor filter, so I plan to attach a hose to the petcock under the water separation cup and drain the tank through there. I'm not going to try to drain the filter dry, because I don't like creating air pockets in the system. I plan to keep the end of the drain hose a few inches above the Racor filter so the fuel flow will stop before the Racor starts to empty.
QuoteI am preparing to drain it for the winter like Maine Sail recommends.
As I posted, I remove the fuel gage plate, 3 screws, then I use a siphon pump to take fuel out. This would be much faster and I believe much neater than pulling a fuel hose. Here is what I use.
https://www.northerntool.com/shop/tools/product_200407825_200407825
FWIW also use it to transfer gas from 5 gal jerry can to 1 gal dinghy gas can. The new gas cans with the lawyer designed spouts are a pain to use and difficult to pour from without spilling.
Jim
I know what you mean, Jim, about the lawyer designed spouts. They think they are helping by making them safe, but people are more prone to be spilling gas. Wonder how many people blow themselves up by igniting spilled fuel!! I have pre-regulation gas cans with normal spouts. I hope they last forever.
Interesting about the website about the siphon pump. It shows siphoning out of a car. I remember during Hurricane Sandy, gas was just about impossible to get (no electricity, no way for stations to pump gas). I had to fill the tank on a generator for my house so I tried to siphon some gas out of my car. I couldn't. I later found out that cars have an anti-siphon design, so nobody can steal gas out of a car.
Roc: In that photo I thought they were putting gas into the car not syphoning it out.???
Breaking : If you only have 5 gals of fuel in your tank - I'd remove it this spring before launch, clean it, reinstall and then you know that you have a clean tank. Not that much work!!
I've known C34 owners that have had their flex hoses NOT attached and that could? have been JonW's problem which allowed all that sludge on the very bottom to accumulate!!
A few thoughts
Ha!! Noah, you're right :D
I finally made it to the boat today and planned to remove the wooden panel to expose the fuel tank. After getting all the stored junk out of the way and removing all the screws, I discovered that my A/C vent grill protrudes far enough from the front wall to prevent removing the panel. I unscrewed it briefly, but separating it from the vent hose required tools that I didn't have available, so I put it back in place so I wouldn't misplace the screws.
NOTHING on a boat is ever a easy as it seems.
Quote from: Breakin Away on December 22, 2019, 04:51:01 PM>>>>>>>>>>>>>>>
...so I put it back in place so I wouldn't misplace the screws.
NOTHING on a boat is ever a easy as it seems.
True that.
Did you put the vent back in place or the whole "wall?" I took my wall off many years ago, but put it back with only three or four of the twelve screws. Put the screws in a plastic bag clearly labeled as "Fuel Tank Wall Screws."
Good luck, I hear the second time around is a charm! :D
Quote from: Stu Jackson on December 23, 2019, 09:46:38 AM
Did you put the vent back in place or the whole "wall?" I took my wall off many years ago, but put it back with only three or four of the twelve screws...
My wall is held in place by only 3 or 4 screws along the bottom. There is a fiddle that is molded into the top ceiling liner that locks in the top edge. (Perhaps this is an "improvement" made in the MkII boats?) There is also some teak trim piece that locks in the aft edge. So the only way to get the panel out is to pull out at the front edge, where the 1/4" protrusion of the A/C vent prevents getting it out.
If the whole thing was held in by 12 screws, with no other molded things holding it in, then I could probably pull out from the aft side and work around the A/C vent. But right now it's constrained on three of four edges, so removing the bottom screws is not good enough to get it out.
QuoteI finally made it to the boat today and planned to remove the wooden panel to expose the fuel tank.
On Shamrock the aft panel needs to be removed before removing the port side panel, to remove the aft panel the steering cover needs to be removed. All are Philips screws of various sizes and length. When I do something like that I sketch what's getting dissembled, the panel in this case, on a piece of cardboard then stick the screws in the cardboard where they came from. They all may be the same for you, there's no reason for the assorted screws, think it was what the guy at the factory had at the time.
As long as you are doing all that work, check that your fuel vent hose goes as high as possible. When Shamrock has a very full tank and is healed well over sometimes get a little over flow from the vent. On my list to fix if I'm in there.
Like you said, nothing on a boat is ever as easy as it seems.
Jim
Guys : Jim is saying that on a MKII the aft cabin panels are interlocked just the opposite of the MKI (starbd first and then aft).
On the MKI there are two lengths of panel screws. Just make sure that you don't use the longer screws for the aft panel or you might screw a hole in the aft water tank!!
Just use a "heads-up" when taking things apart and note differences!! :thumb:
A few thoughts :santa
Quote from: Ron Hill on December 24, 2019, 02:49:02 PM
Guys : Jim is saying that on a MKII the aft cabin panels are interlocked just the opposite of the MKI (starbd first and then aft).
On the MKI there are two lengths of panel screws. Just make sure that you don't use the longer screws for the aft panel or you might screw a hole in the aft water tank!!
Just use a "heads-up" when taking things apart and note differences!! :thumb:
On the subject of noting differences, the panel on my MkII are not like Jim's. The side panel overlaps the aft panel slightly. It's close enough that it looks like it could go either way depending on the order you put in the panels, and/or how precisely the panels are aligned. (i.e., if one panel is allowed to "sag" a bit before the screws are tightened, then it sticks out a little and may lock the other one in)
I have not actually removed my side panel yet, but that's what I saw when I went back there:
I finally made it down to the boat today and succeeded at removing the side panel (3 screws along the bottom), so it's time for an update to point out a significant difference in my boat vs. the others mentioned here:
I HAVE A PLASTIC FUEL TANK. I assume that Catalina switched over to this at some point, because I can't imagine why the tank would have been changed out. Does anyone else have this? If so, is it before or after my MkII #1535? Please let me know what you have.
Note the pictures. There is NO WAY I can get to the gauge cover to remove it from the aft berth - I'd have to remove the covering wood(?) in the cockpit locker to get to the top of the fuel tank. It's just too tight a fit (see picture). So I can't use the fuel pump that I purchased to drain the tank like Jim Hardesty suggested (but he's got #1570, so did Catalina switch back to the older design?). Instead of pumping, I pulled the hose off the Racor inlet port and gravity-drained it into a jerry can. I got about 5.5 gallon out of it, which is exactly what my fuel gauge said I should have based on the prior calibration that I posted last year. Since that calibration assumed the rated capacity of 25 gal, pretty much confirms that my actual capacity is 25 gal with this apparently different tank.
Also, comparing my picture to the ones posted by Dave Spencer and Jon W, it's clear that my tank is mounted higher above the floor (greater head pressure so boat can run without lift pump?), and the overall enclosure is shorter because it does not extend the entire length of the aft berth - the enclosure stops about a foot short of the forward wall of the berthing area. This tank is a much tighter fit both vertically and horizontally, which eliminates good access from the aft berth. I can't even see how I could remove it if I wanted to, because the mounting brackets are blocked by hoses and other stuff.
This Catalina Direct listing seems to explain the history:
QuoteIt is reported by Catalina that this aluminum fuel tank was installed at the factory beginning 2/5/2004. But it is also reported that it replaces earlier plastic fuel tank and even earlier aluminum fuel tanks if the tank was installed aft, to port of the aft berth.
https://www.catalinadirect.com/shop-by-boat/catalina-34/engine/fuel-tank-25-gallonc-34-c-36/
I'll have to measure the tank dimensions for comparison with my opening, but it seems my fuel tank nook has much less vertical clearance (floor much higher) than the one that Dave Spencer showed. Looking a Jon W's new tank, I doubt I could make that one fit because of the fill port on top. But it looks like CD has their tank with the fill port on the aft end, which might fit. I don't need to replace my tank, but nevertheless it's interesting to see these differences between the different boats.
Here are some pictures for comparison:
Mine(https://c34.org/bbs/index.php?action=dlattach;topic=10409.0;attach=10345;image)
Dave Spencer(https://c34.org/bbs/index.php?action=dlattach;topic=10409.0;attach=10206;image)
Jon W(https://c34.org/bbs/index.php?action=dlattach;topic=10409.0;attach=10216;image)
Catalina Direct's current tank offering(https://www.catalinadirect.com/images/products/2314/A8248_S01_md.jpg)
Breakin,
On Shamrock there are 2 deck plates accessed from cockpit locker, one for the fuel shutoff one for the fuel gage sender.
https://www.westmarine.com/deck-plates
If you don't have them, it may be good to install them.
Sorry that this project isn't going easy.
Jim
You can barely see the underside of the two deck plates Jim is talking about at the top of the photo of my tank you posted above.
Guys : In the late 1990s Catalina had 2 replacement fuel tanks for the C34 - aluminum and plastic.
It is my understanding that they discontinued the plastic tank. Owners complained that their plastic tanks had become permeated with diesel and the smell of diesel was overpowering.
A thought
Breakin,
As others have stated, I too have an access plate in the port side locker to get to the fuel shut-off valve. But just one, not 2 like Jim Hardesty has on Shamrock.
Looking closely at the pictures you posted comparing my tank, Jon W's and yours, it's clear that Catalina made some change to the design of the port side wall sometime between my boat (#1279, 1994, Mk 1.5) and your boat (#1535, Mk II). You can see the tank is much higher. The lip supporting the "teak" sidewall looks to be in the same place but the tank floor looks to be at least 150mm (6") higher and the forward wall in your fuel tank compartment looks to be 200-300mm farther aft than the lip on my tank and Jon W's making your fuel compartment much smaller although the tank is reported to be more or less the same capacity. Also, the tank appears to be 100mm or so farther aft than mine and Jon W's.
Do you know what is under your fuel tank? Surely the effort to redesign the area and create a cavity under the tank had to be for some good purpose. I doubt that it was to allow fuel to flow without a lift pump... mine does that without difficulty. (There are lots of discussions about the purpose of the lift pump and its interconnection with the oil pressure switch in previous posts.) Also, it looks like you have a solid wall along the forward side of your fuel compartment. Do you know what is forward of that wall? I don't have a wall and my fuel tank is open to the plumbing, and water muffler accessible through the cabinet under the sink in the head. If my arm was long enough, I could reach the fuel shut-off valve from the head. That area always struck me as wasted space so perhaps some good use was found for it in the Mk II boats.
Sorry I'm not much help but it's interesting to see some of the differences in the C34 across the production run. Many of us are aware of key differences between Mk1, Mk 1.25, Mk 1.5 and Mk II boats but I haven't seen anyone point out this difference before.
Good luck with your project... it sounds like it will be a challenge. Maybe a phone call to Gerry Douglas or another long term employee at Catalina is in order.
Breakin—Don't take Jon W.'s tank as "standard", especially for your MkII. He has a 1987 MkI (different than MkII) and he had his tank custom made with size adjusted, the fill hose fitting moved to the top of tank and two tank inspection ports added.
FWIW - in addition to adding 2 access plates and relocating the fill port, material thickness was increased and I added a flange to the aft end of the tank for a screw to secure that end of the tank to the wood support.
Hi all, sorry about the delay responding. For some reason, I didn't get email notification of the responses.
The "project" is pretty much complete. My only reason for trying to get into the top of the tank was to pump out the ~5 gallons of leftover fuel for inspection and storage over the winter in a verified clean jerry can. Given the difficulty getting access, I drained it through the hose by gravity/siphon. The fuel looks real clean, so I don't feel any need to remove or open up the tank.
A few responses to your comments:
Fortunately, I have no diesel odor (even after pulling out the wood panel) or other sign of permeation of the tank. No need to replace it. The panel will go back on after I bring a vacuum down to suck way any dust around the tank.
I am also curious what is under and forward of the smaller "cabinet" for my tank. There must have been some reason they made this design change, but until I can dig around again back there, I don't know what's behind the fiberglass.
I do have two deck plates in the port cockpit locker, both located at the forward end of the locker. I've used the fuel shut off valve several times (though more recently I use a pinch tool to shut off the fuel closer to my Racor pump when changing the filter). The second inspection port probably covers the fuel gauge sender, though as I recall it is not well centered on the opening. If I ever wanted to get it out, I would probably have to unscrew the tank and shim it a bit to get the sender centered. I do not recall seeing a third port further aft, like Jon W shows in his picture.
In the springtime, I am probably going to pump some fuel though the rubber hose into the tank through the dip tube. Doing this at a high rate of speed may loosen any stuff that may have coated the hose. Then I'll pump it back out again and inspect to see what's there. Rinse and repeat. But so far, everything looks pretty clean except for a little solid residue in my Racor filter (which is why I'm inspecting my fuel so carefully).