GRP Fuel Tanks

[Nos4r2]

Originally Posted by jwalker

I agree with codders, I can't speak for aluminium alloys but stainless can certainly be a problem. Given that many aluminium alloys age harden and work harden then.....

He's right-certain grades of ally do work harden.
Aluminium alloys are a big can of worms though. It'd take an essay and data sheets to show what can happen to them after welding.

[pathalla]

Originally Posted by codprawn

GRP tanks have certain advantages - stainless and ali tanks can fracture quite easily with the constant pounding.

Oh don't tell me that Cod... like I need another thing to worry about...

[codprawn]

Originally Posted by pathalla

Oh don't tell me that Cod... like I need another thing to worry about...

It all depends how they are made - how they are mounted - and what sort of alloys they are made from.

Also the bigger the RIB the less of a hammering they get. My hull gives such a soft ride I could probably have glass tanks.................

[Cookee]

Most race boats in the classes I have raced in have Ally tanks - stainless ones have a habit of splitting at unfortunate times - ask Richard Strawford about having an above deck tank made in Egypt to replace his built in for life Stainless tank in a race Pascoe Rib. We have done diesel tanks built in and part of the hull as per CE regs, but Scott Bader will not commit themselves as to the suitability of their resins with the new additives in petrol (insert Codders comments here), and if they won't commit then they won't get past the CE or worse still the coroner when it blows up.

[nik]

The resin for fuel tanks is Neo Pentyl Glycol.
more information below.

Neo Pentyl Glycol

Nick.

[Searider]

My Scorpion has a GRP tank.

Comments about ethanol are interesting to note - Tesco 99 octane has bio ethanol in it. Probably best stick to the regular petrol!

[jwalker]

Scott Bader NPG resin data sheet. Resin recommended for use up to 25% alcohol.

Maybe there's something else about petrol which worries them.

[Limey Linda]

Originally Posted by Searider

My Scorpion has a GRP tank.

Comments about ethanol are interesting to note - Tesco 99 octane has bio ethanol in it. Probably best stick to the regular petrol!

In the US the % ethanol must be declared by a sticker on the pump. Have not heard of anywhere selling more than 10%. Generaly the higher the octane the lower the ethanol. It still makes me very nervous of damage caused to engines, which is the big risk not leaking tanks.

[Dirk Diggler]

Originally Posted by Cookee

built in for life Stainless tank in a race Pascoe Rib.

Pascoe's tanks were ally!

[Pete7]

Topical news item on MBM

http://www.ybw.com/auto/newsdesk/200...17mbmnews.html

Originally Posted by Dirk Diggler

Pascoe's tanks were ally!

and it leaked oh dear, Mark should have listened and used titanium then , we used to have a real expert on here called JF who had the ideal solution and wouldn't have added much to the overall cost of a Pascoe Rib.

http://rib.net/forum/showthread.php?...tanium&page=14



Pete

[Searider]

Perfect timing:

http://ipc.chtah.com/a/hBH-jh3BwD7M8...B5PNBNBj/ibi13

[jyasaki]

Originally Posted by Limey Linda

In the US the % ethanol must be declared by a sticker on the pump. Have not heard of anywhere selling more than 10%. Generaly the higher the octane the lower the ethanol. It still makes me very nervous of damage caused to engines, which is the big risk not leaking tanks.

The disintegrating glas fuel tanks were from a specific era (generally, I believe, the 60's and early 70's.) Prettty common on Bertram and Hatteras boats. As someone stated earlier, it's believed that the vinyl and polyester resins break down with exposure to the alcohol.

Modern fiberglass resins should not be a problem.

I believe the alcohol sticker thing is only mandated if 10% or over. Not sure about that though.

The alcohol is added as an oxygenator (not, as many surmise, to reduce the amount of gasoline per gallon as a fuel saving ploy); it is a replacement for MTBE which has been proven to remain in the environment for a lot longer than is healthy. Alcohol burns less readily than gasoline, so it should raise the octane rating of fuel (octane rating being the "explosivity" of the fuel mixture.)

There are several problems with ethanol, besides the disintegrating fuel tanks: fuel line composition must be alcohol tolerant or they fall apart; the alcohol may dissolve accumulated sludge and such that is not affected by gasoline - this then clogs filters and fuel systems; the water absorbed by alcohol may affect aluminum fuel tanks, especially if it separates out (which is not necessarily attributable to ethanol exclusively; you can get water in a straight gasoline as well); reports of phase separation causing excessively lean, low octane fuel mixtures or complete water blockage; etc.

The article referenced was pretty vague about just who was included in the class-action suit; I'd be surprised if they simply lumped everyone in, as it would be tough to prove the damage was caused by ethanol on most newer boats.

jky