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Fuel tank leaking
Posted: April 1st, 2021, 11:32 pm
by brianshahan
Just bought a Carver Santa Cruz 25 foot with a remain 351.
Starts great but the guy that I bought it from took me for a serious ride. I am working on it at a friend's and the fuel tank is leaking. I scooped out 5 gallons and there is still standing gas. Tomorrow going to siphon out the rest. What can I do to repair/ replace the tank?

Re: Fuel tank leaking
Posted: April 2nd, 2021, 7:33 am
by Midnightsun
I would probably replace the tank but more importantly use extreme caution, this is gasoline, one little spark, wrench slip, unintentional metal to metal contact, static electricity and bye bye.
True story, about 20 years ago when I was leaving for a 2 week vacation with my 28 express, we stopped to fuel up at a marina however it would not take gas, kept burping. The attendant went into the bilge and removed a tank access plug on the tank top and he proceeded to fill. He did not monitor this and about 5 gallons of fuel emptied into the bilge. Only reason anyone noticed was i had a fume detector and automatic bilge blower activation which went off. Talk about a freak out situation, 5 gallons in the bilge and a full tank!!. He put a garden hose into the bilge and just let it run while using the pump out hose to empty my bilge. Talk about breaking every rule in the book. I still squirm when I think about this today, could have been the last day my family and I were on this planet.
Welcome aboard.
Re: Fuel tank leaking
Posted: April 2nd, 2021, 10:13 am
by SplashyLady
Be careful removing that gas!

You will probably need a new tank once you get the gas removed, as repairlng a leaky tank is usually just delaying the replacement for a short while. The best deal you will likely find will be from Alloy Metal Works. Take measurements and some pictures and call Phil. They can usually fab you a new USCG approved tank and ship it to you in less than 2 weeks. Great folks to work with. Check the hoses carefully - it may be time to change them as well.
Alloy Metal Works
https://www.alloymetalworks.com tel: 631-694-8163
Re: Fuel tank leaking
Posted: April 2nd, 2021, 10:39 am
by km1125
Do you know where it's leaking?? How full was it when it was leaking? Is it still leaking? Is it possible the leak was really at the fill hose and just ran down the tank? Did you fill it and it leaked at the sender?
If it's definitely the tank, then I agree with the previous replies... don't repair but replace it, and be careful doing so.
What is the tank made of? Back then some were galvanized steel.
Re: Fuel tank leaking
Posted: April 2nd, 2021, 11:18 am
by VicB
So just as an opinion, what is the best way to get the gas out? You can find plenty of different style pumps, but most say they are for oils or diesel. I always thought one of those 12 volt transfer pumps that looks similar to a fuel filter would be best. Issue there is its DC. Easy to get a spark when connecting, disconnecting and turning on. If you have gas in the bilge and 30, 40 or 90 gallons in the tank, what do you guys think would be the best method for removal? All of us with aluminum tanks may eventually be faced with this, so this may be a great learning opportunity for us all.
Re: Fuel tank leaking
Posted: April 2nd, 2021, 12:35 pm
by Viper
km1125 wrote:Source of the post Do you know where it's leaking?? How full was it when it was leaking? Is it still leaking? Is it possible the leak was really at the fill hose and just ran down the tank? Did you fill it and it leaked at the sender?
If it's definitely the tank, then I agree with the previous replies... don't repair but replace it, and be careful doing so.
What is the tank made of? Back then some were galvanized steel.
I agree km, I'd take a really close look before assuming it's the tank and going through what could potentially be a huge expense.
If it is the tank, the best thing to do of course is replace it but I wouldn't rule out a repair, it really depends on the condition of the tank, and to determine that, it needs to be inspected in and out. It will then be your call whether you want to put a repaired old tank back in now that you went through the work of pulling it out. A new tank will certainly give you decades more trouble free worries with respect to the tank itself. While it's out, replace the fill and vent hoses, and the line to the engine if it's warranted or is the older hose that no longer meets code.
You can use a 12 volt pump to remove the contents as long as the pump and hook up aren't in the engine compartment. I use a pneumatic pump for fuel transfer. Having everything overboard is best/safer if you can get a line through the deck fitting. A battery or booster pack should suffice depending on the amount you have. Pretty sure you have aft deck access to the engine compartment and tank so this would be safer as you'd be vented. Close the salon door and windows. Use a long suction line to get you to the tank if you're going through the sender opening for getting the rest of the fuel that you can't get through the deck fitting or the engine feed line. Most guys will then pour in soapy water and pump that out too before doing anything with the tank. You'll never get all the liquid out but the water will make what little fuel is left float to the top in hopes of getting most of it out.
Re: Fuel tank leaking
Posted: April 2nd, 2021, 12:42 pm
by g36
I have and have used one of these to pump gasoline from a bad tank I had on my trojan. Or there's a ton of similar items..
https://www.summitracing.com/parts/mrg-12s
Re: Fuel tank leaking
Posted: April 2nd, 2021, 1:30 pm
by bud37
VicB wrote:Source of the post So just as an opinion, what is the best way to get the gas out? You can find plenty of different style pumps, but most say they are for oils or diesel. I always thought one of those 12 volt transfer pumps that looks similar to a fuel filter would be best. Issue there is its DC. Easy to get a spark when connecting, disconnecting and turning on. If you have gas in the bilge and 30, 40 or 90 gallons in the tank, what do you guys think would be the best method for removal? All of us with aluminum tanks may eventually be faced with this, so this may be a great learning opportunity for us all.
My best advice for anyone confronted with this that has no working safety experience with gasoline tanks .....leave the removal to the pros....they have the proper equipment,like rated vac trucks that can safely suck all the fuel dry and dispose. There are way too many things that can go wrong very quickly. The cost of hiring may be pricey but very much worth it in this case. Just my considered opinion.
Be aware it may be possible that even a cleaned tank can regenerate explosive fumes if left a while.
I do agree about doing some investigation to see if the tank is actually leaking first, but be careful, even battery operated devices can create a spark.
Re: Fuel tank leaking
Posted: April 3rd, 2021, 5:00 pm
by g36
bud37 wrote:Source of the post VicB wrote:Source of the post So just as an opinion, what is the best way to get the gas out? You can find plenty of different style pumps, but most say they are for oils or diesel. I always thought one of those 12 volt transfer pumps that looks similar to a fuel filter would be best. Issue there is its DC. Easy to get a spark when connecting, disconnecting and turning on. If you have gas in the bilge and 30, 40 or 90 gallons in the tank, what do you guys think would be the best method for removal? All of us with aluminum tanks may eventually be faced with this, so this may be a great learning opportunity for us all.
My best advice for anyone confronted with this that has no working safety experience with gasoline tanks .....leave the removal to the pros....they have the proper equipment,like rated vac trucks that can safely suck all the fuel dry and dispose. There are way too many things that can go wrong very quickly. The cost of hiring may be pricey but very much worth it in this case. Just my considered opinion.
Be aware it may be possible that even a cleaned tank can regenerate explosive fumes if left a while.
I do agree about doing some investigation to see if the tank is actually leaking first, but be careful, even battery operated devices can create a spark.
Not everywhere is there "pro's" that come and do this type of thing. It may be available wherever the op is but not everywhere . So yes extreme caution but with the correct items and common sense I believe as I'm still alive it can be done safely without the "pro"
Re: Fuel tank leaking
Posted: April 4th, 2021, 3:32 pm
by VicB
I agree that this could be very dangerous. It has also been my experience that just because you pay someone doesn't mean they are professional and nobody will take the care of your boat like you will. I'm in North West Alabama. Lots of beautiful water. Lots of Marinas. Problem is there are not very many reputable mechanics. Our marina is at a State Park, so no facilities on site to do boat repair. All that said, a smart man will know his limitations before he exceeds them.