Is bio diesel disolving my fuel tank!?

[Handmade Matt2]

We've been using virtually 100% bio diesel in our 1.9D for over a year now.
It's made professionally from waste veg oil.
Recently I've been able to smell it around the vehicle.
I investigated and the fuel tank is oily damp on it's base. There are tiny little droplets of the stuff, it looks like condensation.
The fuel tank is otherwise dry and dusty so oil is easily visible on the dusty surface and there is no apparent oil stain from any of the connections into the tank... No damp oily marks other than a ring in the centre of the bottom of the tank.
(I'm going to get a second opinion on this in case I'm going mad.)

My supplier's a nice chap and he says although he's never heard of it might be possible as it does dissolve some rubber and plastic.

Any thoughts? Any idea what plastic is used on the Berlingo fuel tank?]
Thanks.

[Bernard]

I used to use 100% bio diesel in my Citroen ZX 1.9TD, did about 10,000 miles on it. It can dissolve natural rubber (well, make it swell and crack) which happened to one of the seals in the fuel pump which sprung a leak. Got the car to the garage by keeping revs over 3000 at all time otherwise it cut out (which was an interesting drive!). This was the only bio diesel related problem I had.
The car continued for several years on conventional diesel after the last local bio D. supplier went Tango Uniform. I was impressed with how well the 1.9TD handled the bio diesel, it behaved just like it did before. I had to revert to fossil diesel, I used four different companies to buy my bio fuel, all of which went bust quite soon after I started using them (maybe I was the kiss of death!)

[Ricbob123]

Iv done about 12,000 miles on B100 with no adverse affects, I should think it wont damage the tank as bio only has a problem with natural rubber. most synthetic rubbers and plastics are fine. I'll ask over at http://www.vegetableoildiesel.co.uk
and see what the gurus say.

[Handmade Matt2]

So. Outside the shops today the car started to pump fuel all over the floor. The lads in the local garage opposite put it up on a lift for me and said it was coming out all around the fuel pump. they didn't have time to fix the problem though and my Dad came to the rescue to tow me home.

The car is home now and I just need to resolve this leak. It might well be down to a degraded seal from the bio like you've experienced Bernard.
I'll have a look and try and do it myself. Any advice is welcome.
Failing that I'll call a local mobile mechanic.

The grease on the fuel tank must be just muck and I think is totally unrelated now.

[stuartinlancashire]

It sounds like you found the answer to your smell Handmade Matt2, the bio has probably been seeping out from the fuel pump and the smell has been coming in through the vents.

[Ricbob123]

Just to wrap the plastic tank and bio issues up, most cars now have plastic tanks particularly the French brands and land rover line as well amongst others. No issues have ever been mentioned so i think its safe to say bio in plastic tanks is all good.

This comes from the guys that know over on http://www.vegetableoildiesel.co.uk