Bad Fuel Tanks

rasbury

I posed this question on another thread where someone was having the dreaded fuel tank problem of leaking. From what I have read on here, it's pretty much a kiss of death to your boat as the repair cost for most of our boats can be close to what they are worth. When I first got my boat I was having some issues at the ramp. I was looking at various bladders that I could put in the back up my truck, fill with water at the ramp to give me traction and then pull the plug on it and drain it back. Still think that is a good idea for when you need it but I resolved otherwise.  In my searching around, some of these bladders are rated for all sorts of chemicals including fuel. If we opened up the end of the tank, why could you not stuff one of these bladders up in the tank and then wala, no more leaking tank?

Michael T

Yeah, why not? Wonder what the USCG and insurance companies would say?

Black_Diamond

Fuel tanks in helicopters are bladders. Developed to withstand crashes and not leak. 

PartsMan

Is the fuel pump in the tank? What about the sending unit? Will the bladder suck in when it empties?

Most car are now being built with plastic fuel tanks. They will never have to be replaced unless damaged in an accident.

Handymans342

I agree about Plastic. Why cant tanks be plastic in boats?

Stodge

They were fiberglass at one time.  But ethanol eats fiberglass resin so they were switched.

rasbury

OK Guys, your losing focus on me! The issue is dealing with metal tanks that fail, not why they don't do them differently....

Handymans342

If it starts to leak, why cant you replace with a plastic tank? 

PartsMan

Here's some questions that need to be answered for a badder...

Is the fuel pump in the tank? What about the sending unit? Will the bladder suck in when it empties?

MarkB

You would need to find a way to reconnect the fuel pump and the vent. Good points partsman.

Michael T

IMO -  I'd see first if I could get a USCG and Insurance certified "bladder". If you can't the rest is a waste of time. If you can then I'm sure a fuel sending and volume calculating apparatus will be easy. If it's that or scrap the boat I bet you can get creative! First though find-out if it's even legal!

rasbury

Ok guys, your bumbing me out here, lets go back to royalties living on my big yacht! Nessecity is the mother of invention...imagine if we could put this together, get the cc approval the insurance CO's would fall in line...a repair cost could be less than a couple grand a tank tops vs scraping a boat...

Michael T

Hey Ras, I kid you not, I REALLY think you are on to something. Just imagine a guy is faced with LOSING his boat due to an insane repair bill and he is offered a way to fix it at a fraction of the cost. For God's sake most of you guys are Americans - you invent stuff and don't quit! There has to be an alternative to scrapping a boat because of a friggin' fuel tank fail! Go Ras!

F1100

I have been thinking about this issue as well, having used some ATL fuel cells in race cars. Since this is such a major issue for a boat owner.

Instead of ripping up the boat, why not use the lower rear birth area and add in two 75 gallon tanks or a large single tank, rebuild a separation wall, and just turn the lower birth area into a long seat instead of a table area?

These leaks are usually on older boats, where IMO it does not make sense to throw thousands in labour ripping the lower deck apart pulling engines out ect ect. You could just pull out the rear birth seats, and add two tanks/large single, then build a wall to separate them, and then just recarpet.

Michael T

@F1100 - great idea!

Schlub

If you want to use plastic fuel tanks they have to be roto molded (rotational molded) high density polyurethane. First you build the mold...let's say 5K...then a roto molder can kick out out about 10 tanks a day. Soooo...get a group together and invest in the mold and generate tanks. I can supply a design and fittings for vents and supplies from a tank we made back in the 80's for the import mini pickup trucks. We would want to get close to a 100 people to bring the cost down to "cheap".

rasbury

Schlub- the original idea was a repair not a new design. The last boat I had which was a bow rider type boat had a plastic tank that was below the upper deck. My idea was if you had a metal tank that was bad. On my boat, there is about 12" or so of exposed tank before the genny. If you had a 'custom" bladder that you would cut a hole in the tank, shove the bladder in there and then hit it with air. Then, it would fill the metal tank and provide a liner and thus solve the leak. I don't think there is anything really new about plastic tanks. I know my fuel pump is engine mounted so there is nothing in the tank that I'm aware of, at least on my boat. I think it would work. I'm not sure how many boats this happens to and how many varieties of tanks there are.

Schlub

sorry.  polyethele (crosslinked) not polyurethane...

Schlub

here is a 29 gallon off the shelf roto molded gas tank / northern tool / cost is about 80 bucks to manufacture
   http://www.northerntool.com/shop/tools/product_200445835_200445835?cm_mmc=Google-pla&utm_source=Google_PLA&utm_medium=Fuel Transfer + Lubrication > Auxiliary, Transfer + Skid Tanks&utm_campaign=Moeller Marine&utm_content=483742&ci_src=17588969&ci_sku=483742&gclid=CjwKEAiAwZO0BRDvxs_1w-qFnhkSJABo10ggJx7aMy-IvdGrp5DQjsB3hSxn97HVZaN1UusAXGVOcBoC1iLw_wcB

Schlub

the bladder idea is good but most bladders will not tolerate ethanol as they're use is for aircraft or diesel

robc

I was at c&d marine of Long Island today checking on progress of tank removal on my 1999 270. They had the drive off the engine out the floor cut out and the tank removed. Very professional outfit. Four obvious holes in tank. The cause is tank rests on molded fiberglass. Salt water after it gets under has no where to go. The drain holes on board separating tank to bilge are a couple of inches high on sides. When they put it back together a drain hole bottom dead center should be done. 
While motor is out will change fuel pump, impella and oil pan at a minimum. 

Handymans342

So the tank corroded from the outside in?

Handymans342

What will the new tank be made from??

Michael T

@robc, sorry you are having this expense -  smart of you to replace parts while the engine is out. 

rasbury

this is what I'm talking about....rather than tear the whole boat apart for what I would think about 10 grand to put it back together......

rasbury

almost sounds like a problem we will all have at some point!