what material is the best to make fuel tank ?

Back about the time we were making this boat The proffessional boat builder magazine had an artical on making fibreglass glass tanks !!
Some one must be able to find it !!.

 

I have posted this before here. Our tanks for diesel are made from vinylester inner layer and then
gelcoated once and topcoated once. Baffels are 8mm fiberglass panels and you can use plywood instead of airex foam.

"The "box type mold" I make out of 15mm
airex foam panels and I put 450 gr. strand mat on them before I fit them in. The thickness of the tank
is from 5 to 9 mm on the inside. The whole tank is glassed in 2 turns, with the flange. The tank on the photo is 900 liters.To bed down the top
panel I would not use thickened resin, I would use Scott badder 1152 or approved fiberglass bonding paste.
Here is a link to photos of my tank and I hope that you find them useful to look at."


Axel

 

Good Idea Everything is going plastic these days --------is'nt it.

Understanding the limitations of what was normally thought to be melting plastic. Amazing what engineers can come up with by fully understanding the material and make it work..

However it has to be said that getting off a flaming vessel with moulded plastic tanks would need to be immediate , where as fuel contained in alluminium would not need such immediate necessity.

 

Yes mate, i built them in place after the hull was built as i did not know i would be making my own FRP tanks at the time...

My boat is a foam sandwich constructed boat.... so where the tanks were to be built in the bottom of the hulls, i already had a foam sandwich hull as a forma... all i needed to do, was laminate over the existing inside skin with more glass using a fuel resistant resin to form the inside surface of the tank. Baffles were fabricated using kelgecell foam sandwich panels prior to the fact, again using vinyl ester as the matrix and tabbed into place with the extra tank lining laminate, all wet on wet with VE resin. Commercial boat construction standards, specify that FRP baffles must be made from solid glass, not cored panels like this - recreational standards do not specify this requirement.

After the baffles and inside skins were completed, FRP bonding angles were made and glued into position ready to accept the top panel of the tank - which has a bolted on access panel, through which all the fittings for fill, breather, pick-up and level sender etc will be mounted. The top panel is simply "splodged" onto a bed of structural bog and left to cure...

The tank internals, baffles and bonding angles glued in place around the top perimeter ready to accept the lid...




The foam core lid just showing access panel cutout before the internal skin was laminated....

 

My choices would be
1/ plastic, in fact i just installed 2 x 12 gal moeller tanks in my Gemini cat for gasoline.
2/ fiberglass with vinylester resin, if its good enough to store gas and diesel underground at thousands of gas stations across the US after digging up and removing the steel ones its good enough for me, yes its work building them which is why if i can buy plastic ones off the shelf i do as they are cheap, however sometimes you just cant find ones that fit.
I would never use aluminum again for any tank.

Steve.

 

I have done more then my share of gas tank repairs on Skaters with Epoxy tanks which takes a host of materials to do the job , because Ethanol is actually a solvent that eats away ........at epoxy . http://www.seriousoffshore.com/forums/painting-fiberglass/10408-old-don-q-rum.html

 

In , refrence to my last post other manfactures in the past have had great success with fiberglass tanks when used for diesel fuel with no problems .

 

In the shipyard there is a twin screw 50 ft plastic production motorboat with leaking integral diesel tanks. To get in and correctly repair the leaking tank both engines, engine room plumbing, cabling, and part of the saloon must be removed. Very expensive job with no guarantee that the repair will last.

If these were Plastic or metal tanks the repair would be much easier.

I pity the man paying the bills.

 

Michael,this is often the case with leaking tanks regardless of what they are built of, i once had to replace a leaking metal diesel tank in an old wood Grand Banks 42, to remove it from the top would have been impractical for the reasons you mentioned, i blocked the boat up and removed it from the bottom as i needed to replace the oil saturated planking anyway. The point is many builders make no provision at all for removing/replacing things.

Steve.

 

But...when the job was finished you could guarantee the results.

I have no faith in any diesel soaked composite repair.

How do you clean soiled fiberglass . Trichlorethylene ?

High class boats ensure that tank access , cleaning and repair are possible.




I'm in the tanks of a high class boat right now. Flanged manhole covers on 500 liter tanks.

Expensive detailing.

Very little damage to get in, inspect, clean and sign off for the next three years.

 

You have internet access in the tank? That is high class!
Size has something to do with it. For us peons who can't afford large boats, access to lots of things are the usual problem. A large percentage of boats are built with no concern for aftermarket problems, as it is not their (the builders) problem. Their problem is making sure if fits out the door and then that the check clears the bank. Even if consideration of access is accommodated, the logistics of size and assembly sequence can make it difficult, as everything is crammed in and then the deck is put in and fastened down because that's the only way to do it.

 

It dosnt have to be a megayacht to allow reasonable access to remove things like tanks and engines without expensive destruction, it just requires that the boat be well thought out. Ive built smaller sailboats with the engine under the cockpit with the tank behind it,so we installed the sole so it wasnt bonded down but rather caulked down and mechanically fastened with the fasteners plugged in the teak margin so removal was easy as long as you knew where the fasteners and this info was included in the ring binder with everything else. A lot of the problem comes from boats being developed by marketers and built by laminaters and boat carpenters and very little involvement of boatbuilders.

Steve.

 

Let's face it Steve 9 times out of 10 if it looks good on paper , and down the road appears to be having a problem it most likely has something to do with the design or how the boat was engineered ,but in this case ....................with Epoxy tanks or vinyl , there really has never been a problem until Ethanol came along which is something that is only going to get worse considering i only deal with tanks in High performance Boats repair or replace , going with Aluminum , Bladders ,or Rotor molded Fuel cells .

 

with the mega yacht i was a part of each and every tank had a man hole and on the long tanks one at each end of each tank . !

 

A few,ok maybe 10 -15 years ago they were replacing the underground tanks at a lot of the gas stations around here with fiberglass/vinylester tanks so im thinking they are ok for the amount of ethanol in our fuel, i havnt seen any being replaced lately, i would be more than happy to use them on my own boats but even building them myself its not as cost effective as just buying the polyethelene ones unless you dont value your time of course.