My Seacraft
 

So I replaced the corroded battery cables and got it all cleaned up and ready to run. Motor ran good in yard and then I smelled fuel. I check under the deck hatch and I have fuel in the section where the tank is. So the question is two fold, one is it safe to keep running the boat? And 2 my aluminum tank is only like 5 years old is it likely that it has a pinhole in it already? The fuel hoses are getting older, but the one that runs to the motor is staying pressurized. The fuel fill hose and fuel vent hose are older than the hose that runs to the motor, but I didn't put any fuel in so I doubt its either of those hoses leaking.

I may even consider off loading this boat at this point.

Sigh

Find the leak(s), fix the leak(s) and run it. But not until then.

How full is the tank? I am helping my parents with a similar problem on their 18 SeaCraft. Their situation is a clogged vent hose and the majority of the fuel going in the bilge when the marina topped off the tank last weekend. I’m pretty sure Gfs had a fill hose that was leaking gas. Seems like I recall someone saying that when the tank is totally full, fuel can get back into the fill hose and the leak if the hose is compromised.

I dried the area so I will be checking it tomorrow to see if new fuel is there. The tank is currently about 3/4 full. I will take some photos of everything perhaps you guys will have some suggestions.

The fill and vent hose on mine were dry rotted and cracked severely. I would be surprised if a tank corroded that quickly.

I had fuel in the bottom again after drying it out yesterday the boat hasn’t moved so could a fill or vent hose that is bad cause fuel to leak out if the boat didn’t move

Besides pressure testing the tank, there is a real possibility that your hoses could be causing the problem. Unless the tank is defective after five years.

I checked the fill fuel lines and the vent hose line both are dry. As I said they are older and I will gladly replace them but I am worried that the leak is not from them. How do I go about getting the tank pressure tested? How do I get all the fuel out to be able to remove the tank. It looks like a 20 - 30 gallon aluminum tank. The previous owner said it was installed a year before I bought the boat. so around 2014 to 2015.

https://farm8.staticflickr.com/7841/...c8aa9a0f_h.jpgimage1 by TomParisOBC, on Flickr

https://farm8.staticflickr.com/7865/...dc1c8dba_h.jpgimage1 (1) by TomParisOBC, on Flickr

https://farm8.staticflickr.com/7819/...8f32feec_h.jpgimage1 (2) by TomParisOBC, on Flickr

been watching videos on youtube on how people don't install the tanks correctly and they use foam (which mine has) and how air cant get in and dry the water and the water slowly eats a hole in the tank and then you have a pinhole.

Worse if this is the case for me, then it sounds like you are replacing the fuel tank as it is unrepairable.

Sigh...

I spoke to GFS today, he said he would chime in about pressure testing the tank. Those hoses look old and suspect.

Appreciate the help though, just frustrated.

NO WAY that tank is 5 years old or less and leaking !!
It had to be a used tank...
The mold and tree debris & butt splices in your pics pretty much prove that ...
There is a tank company in Perry on Hwy 98 just south of you.

Pull that tank and have a new one made than replace all hoses to boot.

Not that big of a deal, and less than a $1000 for the whole deal if you
DIY....

Just Do-it !

so you think its the tank? Btw my fiberglass floor piece over the tank has always been unsecured, I have lifted it multiple times over the 3.5 years of owning the boat, so the pine needles and dirt on the tank are my fault. But I swear the tank looked pretty new 4 years ago. But Like I said, looked like a cheap job of installing the tank was done. RDS Aluminum is in Perry, FL they also make the gun boxes for the Agents trucks here in Tallahassee for FDLE. Maybe they will give me a discount on a new tank, ha. So at this point before replacing lines etc, you think I should drain the tank and pull it?

Those clamps are new.

RDS has the tank drawings.
Those hoses are old.
About 2 k all in diy.

I had RDS do my SF tank a few years ago. About $10/Ga then. Surprised your tank isn’t painted. Whichever way you go I would paint the tank with coal tar epoxy. Unprotected aluminum and foamed in tank a good incubator for corrosion. Ask me how I know. Good luck.

Drain and pull it.

I ordered a syphon pump, going to drain the tank and pull it. Thanks for everyone giving me input.

Been there done that. Get an old fuel pump and hook it up remotely to a battery.

Tom, does your MA have the 70 gallon option? Didn’t you have an 18 originally, or is this your first SeaCraft?

Michael.

I have only had this boat, and the tank is undersized, the owner I bought it from 3.5 years ago told me he had it replaced and that he chose not to go with a big tank. I suspect the tank is under 30 gallons size. When I pull it I will take some more photos. I am going to reach out to RDS and see how much it will cost to just get another one same size as this one. As I dont go offshore, literally stay with a mile or two of shore. If its too expensive, I may just Redneck it for now and run a 10 gallon above deck tank. Either way I will remove the fuel and pull the old tank myself.

I’m curious if RDS comes back close to $10/gallon. Remember you will have to choose between 0.90, or upgrade to 1.25 thickness aluminum. And then coal tar epoxy.

Vezo

Some thoughts to consider as you address the fuel leak:
That is a pretty good pile of unsecured wires sitting/bouncing on a grounded aluminum tank.
At least one appears to be a large bat (+) cable; likely capable of carrying >>100A in a surge. Maybe 1/16" insulation?
Most small boats do not have a large circuit breaker/fuse on the bat cables.
Others wires appear to have open ends – not sure what they are.
Ever see what happens to metal when a hot jumper cable hits a grounded piece of aluminum?
Be safe.

Smaller vs Larger Fuel Tank
 

About 15 years ago I replaced the 47 gallon tank in my Seafari with an RDS tank of the same dimensions. Seemed like a good idea at the time. Now with only lake use and with an ETEC which is not as thirsty as my Merc V6 150, almost wish I had gone with a smaller tank and gained storage area, as I never have the fuel hatch screwed done anyway. Just a thought.

On my 20 Sceptre, the tank would leak if I filled it to the top. It was leaking at the seal between the sender and the tank. How much fuel is in the tank? Before getting too crazy, I'd be tempted to drain it just below any of the outlets and let it sit again to see if it might be leaking from a hose or sender. If the tank is that new, I'd say those are more likely to be leaking than the tank itself.

Sage advice.

You have an original failed tank.
RDS is thick wall.
CG plate still on the tank?

I think I will have to run off a tank sitting on the deck for awhile. So the question for you guys is, how much runtime would a 6 gallon tank last? Obviously its a guesstimate.

20 Seacraft MA with a 1999 Evinrude 115

Thanks for your input!

get 2 and dont get overly throttle happy
This will give you a rough idea of consumption rates at various RPMs if properly propped:
http://www.boat-fuel-economy.com/evi...ion-us-gallons

how come nobody is running plastic tanks under the deck?

Wouldn't that make it hard to fill up with gas?

In my 20cc rebuild I did a 25 gallon Moeller plastic tank. I plan to run a 115 4 stroke. It wont be an offshore boat and hoping that the 4 stroke is efficient enough to not have to fill up too much. I wanted to keep weight low and prevent having 50 gallons of gas that goes bad before it gets used.

I was noticing you could buy those under the deck Moeller tanks, they cost similar to the Aluminum. I was wondering what are the pros and cons of each. I reached out to RDS Aluminum and they said once I pull the tank to give them accurate measurements and pictures and they will give me a quote.

I got tank out, here are some more photos

https://live.staticflickr.com/7913/3...19747807_h.jpgimage1 (3) by TomParisOBC, on Flickr

https://live.staticflickr.com/7834/4...a7567003_b.jpgimage1 (4) by TomParisOBC, on Flickr

https://live.staticflickr.com/7893/4...27dcecf7_b.jpgimage2 (1) by TomParisOBC, on Flickr

https://live.staticflickr.com/7852/3...d51ba0e0_b.jpgimage2 by TomParisOBC, on Flickr

What are the measurements on the tank vs. the size of fiberglassed hold/“coffin box”? In other words, does the 40 gallon tank sit inside the hold of the optional 70 gallon? And someone was not able to snake all other cable/wiring through the riggging tube, as intended. Definately something to try and correct. Just my thoughts.

This is a pic with the forward fuel hatch secured, awaiting rear. Jus wondering how large your hold is in comparison.

Michael.

Tom, this is the empty and cleaned up hold of my MA, 70 gallon.

so on my '77 all the rigging goes on the outside of the gas tank tub. I think you are going to want to do the same thing when you put it back together.

I dont understand. In my case, the cables, and steering all go through a chase into the compartment on the opposite side from the baitwell and out to the motor. They come through the compartment that has the fuel tank and come up to the helm from there.

How else would you run them?

I do not understand how that tank could only be 5 years old. Looks like 30 to me.

tom: there should be some rigging tubes running outside the stringers. I'd definitely run them in the tube. Did you find the source of your leak? Check this article out for installing the tank, good info: http://www.marinesurvey.com/yacht/fueltank.htm. Good luck.