How hard to pull 25 fuel tank.

breausaw · Posted: Tue Apr 19, 2016 2:07 am Post subject: How hard to pull 25 fuel tank.

So thinking I may have a slow fuel tank leek. If I leave the lazarette hatches closed I smell a slight gasoline odor when I open one, when the hatches are left open I can't smell anything.
So now I would like to pull the entire fuel tank and inspect it along with replacing all the lines.
On my next trip I plan to run the tank down as much as possible then pull the sending unit and siphon the rest.
Based on fuel consumption calculations I figure I lost about 15 Gallons last winter, but maybe I didn't fill my tank all the way before putting it up for the winter. Either way I don't like the idea of gas fumes cumulating in that space .
Time to bite the bullet and open the wallet again.

thataway · Posted: Tue Apr 19, 2016 10:35 am Post subject:

There were many changes on the 25's thru the years. It is possible that you have a floor which can be removed in one piece. If so, not a huge job. I would first try and check all of the hoses, house clamps, sending unit for the gauge etc, before pulling the tank.

Not sure how you calculate the 15 gallon loss. But how much fuel you put in depends on many factors, if by filling up--if the boat is level or lists to one side, the attitude fore and aft, what your criteria is for a "full" tank, as you fill the tank. Maybe even which fuel fill you use, if there is obstruction to the vents, or vent hoses, etc.

If it is leaking 15 gallons, there will be noticeable fuel in the bilge.

If you cannot remove the deck in one piece, then it has to be cut out, that gets to be a real job.

You can often inspect parts of the tank thru current access ports using a "bore scope" There are many used in the car industry that are not very expensive...

journey on · Posted: Tue Apr 19, 2016 1:02 pm Post subject:

First thing is to make sure the tank is leaking. You do not want to pull the tank unless you know it's leaking. Trust me.

Your boat should have to same tank installation as Journey On, since they are both made 2005 and later. Two fills/vents and a removable floor. Here's some pics of Journey On's tank installation.

You can get some smell from the vents. Try putting some making tape over the vents and see if there's still a smell.

If you have to pull the tank, it's a bear. Once you remove the caulking from around the floor, there's only the small number of screws. Again make sure the tank is leaking and where. If you find a leak, then remove the boxes in the corner, remove the vent and fill hoses (boy, am I reliving this as I type.) If you have to pull the tank, and I didn't, cut out the aft retaining blocks and slide the tank up and out. Installation is the reverse. I used at least 3 tubes of 3M 4000 to reseal the floor. 3M 4000 stays white.

Again, make sure the tank leaks before you pull it.

Boris

breausaw · Posted: Tue Apr 19, 2016 6:04 pm Post subject:

Yes, fortunately my 25 has the one piece floor access cover over the tank.
When I fuel it's always at the same gas station on the way home and I always try to park in the same direction because there is a slight grade next to the pumps, so I usually fuel the boat facing uphill. If however I fuiled in the opposite direction there could be as much is a 10 gallon difference. I also park the boat at home with the bow up Stern down, because if it's level or down a bit in the bow gas will start to perculate out of the vents. And the boat is always Stern down while afloat probably more so then when I fuel it would be my guess.
The Mercury smartgauge fuel management calculates fuel usage but is usually about 5 gallons shy at 50 and twice that at 100 gallons usage ( on extended trips I take 35 gallons extra fuel with me in 5-gallon cans) but last year towards the end of the season it was almost 10 gallons off around 50 or 60 gallons at the pump so either the fuel is leaking from the tank or going somewhere else or the fuel management system is not functioning properly. I always just calculate 2 miles per gallon planning a trip even though it averages about 2.5 miles per gallon.
Agree that inspecting the hoses first and all other connections before pulling the tank is probably the best choice, and unless things get worse or obvious I may put it off till the end of the season. If the aluminum tank is starting to pit on the underside these areas can be etched and repaired with epoxy.
So perhaps for now the best approach is to monitor the situation and see if it gets worse. I know that my fuel tank is full at this point and planning a trip next weekend or the weekend after so this will give me some idea if indeed I do have a problem.

Boris, Bob, as always good advice.

thataway · Posted: Tue Apr 19, 2016 7:43 pm Post subject:

Yes, the tank can be cleaned on the outside, and filled with epoxy. BUT, if it is leaking thru these pinholes, then there will be some corrosion on the inside. (Experience). I did wrap a steel tank, which was in a more open bilge, with glass cloth and epoxy, and it lasted many years--basically I had a fiberglass tank, with steel fills, when I got thru. But it was only a 22 gallon tank...

Considering the problem getting the tank out--I would have a new tank built. Have that new tank coated with coal tar epoxy. Too bad that C Dory does not do that to start with!

localboy · Posted: Tue Apr 19, 2016 8:28 pm Post subject:

Someone here had their tank pulled & replaced and posted about it. I think it was David McKibbin (sp?).

In his boat, the tank was laid in then the top cap was put over it. IIRC, he had to literally cut the tank up to get it out. I'm sure a search would yield the thread or PM Pat (Daydream) they are friends. There was some small pitting (holes) caused by corrosion and improper bedding of the alum tank. What a nightmare. I hope I never have to deal with....

Jack in Alaska · Posted: Wed Apr 20, 2016 2:52 am Post subject: leaky tank

Jay,

A leaking fuel tank is my worst nightmare as my CD is also a 2005. The deck is not removable w/o a saw job on it.
So far so good.
Good luck with your project. Let us know how you are getting along with it.
My Deep Creek neighbor has a 1996 CD ProAngler with two 90 gal tanks. One started leaking last year. He cut the entire deck out, removed both tanks and had two 50 gal tanks made. He installed them and replaced the deck. He did an excellent job and he is 83 yrs. old.

Jack

rogerbum · Posted: Wed Apr 20, 2016 9:09 am Post subject: Re: leaky tank

breausaw · Posted: Tue May 10, 2016 12:35 am Post subject:

Okay it doesn't look like I have a fuel leak, what a relief .
The boat sat in my driveway for 3 weeks, I was only able to add about one and a half gallons of gas before the tank was topped off; which is about right because it was sitting lower in the stern then when I filled it at the gas station.
And on returning from our weekend trip shrimping the Mercury smartcraft Gage estimated about 60 gallons and it took about 63.5 gallons the top of the tank, that's an acceptable variance.
So that's a big relief, maybe someone siphoned off a few gallons last winter.
Now I just need to address my temperature gauge issues, but that's for another thread.