what material is the best to make fuel tank ?

[hyboats]

aluminum ? stainless steel ? or fiberglass ?

 

[michael pierzga]

Molded plastic.

http://www.moellermarine.com/oem/fuel_tanks/

 

[tunnels]

aluminum ? stainless steel ? or fiberglass ?

It depends of a few things but mainly size and how they are mounted and where they mounted !! . Aluminium is possibly best !!but outside corrodes so needs a treatment and most all need good ventilation around them !!
Glass tanks can be built into the hullss in big boats , a bit of a pain but anything is possible .
Will be making a glass center tank for my own boat!, but the tank top will be part of the floor inside to get as much capacity as possible and have a uncoated rear end to see the fuel level !! no baffles are required if filled with exsplosafe instead !!. they can be filled with foam like race cars !!.wont exsplode and acts as a baffle !!

 

[tunnels]

Molded plastic.

http://www.moellermarine.com/oem/fuel_tanks/

wow that the best sight i ever seen !!

 

[groper]

Novolac vinyl ester resin is the best, most chemically resistant resin to make fibreglass fuel tanks from if your interested in going that way...

 

[tunnels]

glass fuel tanks i feel are a waste of time in smaller boats and aluminium would be the better material to use !!,STAINLESS is water tanks !
Ethanol is the new fuel to contend with so resins and coatings for the inside skins have all changed in recent years .so built in tanks for small boats are pointless . Big boats are a whole differant senario.

 

[michael pierzga]

Aluminium and ethanol is bad news. Fibergalss is suspect

www.nmma.org/assets/cabinets/Cabinet103/E20_Position_Paper.doc

 

[groper]

Instead of regurgitating here say stuff, do some thorough research into the subject... if you use a highly chemical resistant resin such as a "novolac vinyl ester" you can happily store 100% ethanol in it if you wanted to, E20 is a peice of cake... old polyester and epoxy matrix tanks are a different story...

And tunnels, why are glass tanks in small boats "pointless"??? not a very well thought out statement there mate...

 

[michael pierzga]

Bugger off slaphead. Read the paper then come and look at this aluminium tank I have

Regurgitate. Poof ta

 

[tunnels]

Instead of regurgitating here say stuff, do some thorough research into the subject... if you use a highly chemical resistant resin such as a "novolac vinyl ester" you can happily store 100% ethanol in it if you wanted to, E20 is a peice of cake... old polyester and epoxy matrix tanks are a different story...

And tunnels, why are glass tanks in small boats "pointless"??? not a very well thought out statement there mate...

Ok enlighten me yet again !!
where i come from ethanol is hardly used but i been away a year so guess ill find out when i get home again !! .
Theres one hell of a lot of work making tanks that should pass the test of time ,big or small

 

[Frosty]

Hyboats --what fuel are we talking of.

 

[Ilan Voyager]

Molded plastic.

http://www.moellermarine.com/oem/fuel_tanks/

I do heartily agree...high density plastic. Almost unbreakable, no corrosion and rather cheap. Aluminium is a pain to get truly leak free and corrodes like sugar in hot coffee because of galvanic problems, glass fiber doesn't last (becomes "fragile") and can be dissolved by the methanol mixed gasolines, stainless steel is very expensive and not so strong.

"Theres one hell of a lot of work making tanks that should pass the test of time ,big or small" Yes a lot of time... Truly on a small boat I do not see the need to waste time making the tanks when you have excellent plastic ones for less than the price of the needed raw vinyl resin. I call small boat any floating thing under 60 feet.

 

[groper]

Ilan - i beg to differ...

I needed 2X300litre fuel tanks for storing gasoline (in future the gubment could well mandate compulsory ethanol) so it needed to be resistant to this possibility. The application was for my 35ft powercat.

I had 2 quotes for them to be fabricated in aluminium, the cheapest quote was $1000 per tank = $2000 total. Stainless was even more expensive... I looked into getting them fabricated by a local plastics welder from polyethylene sheet - but he said no, and wouldnt last, i dont know if he was correct or not, but he just refused to do it knowing i was putting gasoline into it... Fuel bladders are also expensive...

So i looked into building my own in fibreglass...

The CURRENT australian standards for fibreglass constructed boats AS 4132, which is based on the equivalent ISO standard, permits fibreglass fuel tanks to be built ONLY from vinyl ester resin due to the chemical resistance and low porosity nature of the resin. They specify a minimum glass weight of 1200gsm in addition to the inside hull laminate. These are FACTS read directly from the standards, not something i heard from someone who heard it from someone else etc...

3.11 TANKS Tanks shall be located in accordance with the structural fire protection
requirements applicable to the vessel.
Integral fuel tanks are permitted only if the skin thickness is increased by 1200 g/m2 of
chopped-strand mat fabricated with fuel-resistant resin on the internal faces of the tank.
All tanks other than those required for fresh or salt water or fuel oil shall comply with the
requirements of AS 2634.
The equations given in Clauses 3.3, 3.4 and 3.7 shall be used to determine the scantlings using
the design pressure values given in AS 4132.1.
Completed tanks shall be designed and pressure tested to withstand the design pressure.

So with this information and the other data sheets available from the resin manufacturers, i built my own... 30 litres of novolac vinyl ester resin was $300 and the offcuts of glass i had laying around and both my tanks were finished in about 8 hours labour. If i had the information earlier, i would have included the additional laminate when i made the hull, for virtually no labour penalty at all.

Other advantages are, less weight, zero wasted space, difficult complex shapes are not prohibitively expensive to fabricate like metal tanks are, no additional fastening of the tank to the hull with associated load shirking reinforcements required...

Back to you...

 

[rasorinc]

Hi groper, did you build the tanks in place for your boat? Did ypu use wood for the sides and bottom then glass inside? How did you do the top? I believe we only have to pressure test to 5 psi here but all the inlets and outlets have to be top mounted. What did you do for baffels? I'm very interested in doing this on my build 9' x 30' V hull and want to form the outside of the tank with wood.

 

[tunnels]

This was the last big boat i worked on back in 2001 making fuel tanks !! carried 16 tons of diesel the whole of the bottom was fuel tanks was a enormous job and took months to complete was all made to DNV specs and because the fillers were at deck level so had to be pressure tested for 24 hours with twice the head of diesel , tank ends sides and tops were 4 layers of combination of biaxle and double bias and csm glass each side of 50 mm thick H 80 core . when assembles had 3 layers of 450 csm and 2 layers of Continuous strand tissue then 2 coats of a special formulated coloured gelcoat suppled by the vinylester resin manufacture , this whole boat was made using 100%vinylester resins . These are the only pictures i have with me at this time !.