Glassfibre petrol tank

[Johnny]

Apologies if this has been raised before, but what's the best thing to do with an old glassfibre petrol tank that has not been used for many years? I've swilled the tank out with petrol to get rid of any loose debris on the M80 I am rebuilding and removed the tap ready for a new one. But the inside of the tank is very sticky with a yellowy brown film that sticks to your finger when you wipe inside the tank. Is this likey to be old 2 stroke oil or something worse like the effect of ethanol? I don't know how long ethanol has been added to petrol and I don't know how long the bike has been stood.

Should I fit a new tap and fill it up and hope for the best or is there something you can use to seal glassfibre tanks?

[pschrauber]

Gummed gas is a task to clean, as it is still liquid you can try carb- or enginecleaner, like Sea Foam in the US and UK?

or Fertan F1 (sold in D), follow the technical description.

If it got really dry (not sticky when touching), even this may not work anymore. Then the only method that works is to remove it mechanically using a tumbler and some stones for tumbling.

How to:

- close the petcock opening very well,

- fill in the stones inside the tank until the stones reaches the level where the gum ends,

- fill with carb cleaner too,

- close gas tap very,

- mount the complete gastank on the tumbler, very importend in the center of the weight!

- best way to attach is using a lot of massive duct tape

- turn on the tumbler, it depends on the thickness of the gummed layer and the sort of stones you took how long it will take, you can always control the process by lookig through the gas tap, (tumbler should be off then).

(I would guess it will take around 3 hours up to a half day.)

You can also use a concrete mixer, (completly cladded inside with foam material, the gastank wrapped with in foam sheets and then tied to the shovels of the concrete mixer, any cavities also filled with foam Material). Bad thing with the concrete mixer is that you can't control the process and every surface of the inner gas tank wil be treatend.

Through the abrasive process you have to paint the gas tank inside, using Kreem (in D) or whatever is recommended and able to deliver in the UK.

The standard glasfiber works, normally no problem with gas, diesel, ... even alcohol. It depends how the joints are closed when building the cave for the gas, thats one of the problem zones mostly. Also bad repaired places where the epoxy is cracked and the fiber is visible from the inside can be get you in trouble.

Edited November 27, 2011 by PSchrauber

[bultaco49]

Hi Johnny

Before you use 'kreem' products to seal or line your fibreglass tank check with the manufacturers that is is compatible. If you Google Kreem and fiberglass together many users have had problems with getting Kreem to adhere to fiberglass. In all the adverts I have seen, where they mention it, Kreem refers to steel tanks only and unless they have a new product out beware. Kreem is extremely difficult to remove from a fibregalss tank if it delaminates(I speak from experience)as Acetone is the recomended solvent. Acetone will also dissolve the fibreglass resin.

There are products, such as Caswell, that specify use for Fibreglass tanks and will protect against ethanol. Ethanol will attack the fibreglass of a Bultaco tank, again I speak from experience. You must line it, use ethanol free fuel or drain all the fuel between uses.

With all tank liners and sealers, if it does not say it is compatible with a fibreglass tank it probably is not.

The best cleaner for tanks (that I have used many times on fibreglass tanks) is 'Marine Clean' available from many places online. Many recommend acetone but this is difficult for the reasons mentioned but also it will take the paint finish straight off. Using pump fuel is no good as it will leave a residue of solvents and petrol that will make adhesion of the liner/sealer less effective.

Tim

[pschrauber]

I did not know that Kreem is available in the UK?

Anyway, if you will still use Kreem there are different products (types) for a gas tank sealant available, also three different products for the preparation, like cleaning, ...

I would ALWAYS call or e-mail the manufactor of the sealant which type of product for preparation and painting you need.

in your individual case.

Number for a call: +49 9721 41455, (they speak english).

E-Mail: herbert.ammon@ammon-technik.de

[woody]

As mentioned by Tim, Caswell's is probably your best bet and they have a UK office so you can speak and check with them first, particularly about the preparation.

Ethanol free fuel is very hard to get and I think it is only 4 star that you can guarantee has none. It's available if you can find a local supplier. I use Shell V Power as it has about the lowest ethanol content and never had a problem with the fibreglass tank on my Majesty, which was made before all this ethanol stuff surfaced. I never used to drain it either, it always had fuel in it.

I think with V power and if you drain the tank after use, you may find your tank won't suffer - but I obviously can't guarantee that, just based on my Majesty tank.

It would be interesting to know if or how they prepare the fibreglass tanks in Spain as many of them use the new reproduction fibreglass tanks, such as the Puma bikes, on the Bultacos and Montesas.

[smelling123]

As mentioned by Tim, Caswell's is probably your best bet and they have a UK office so you can speak and check with them first, particularly about the preparation.

Ethanol free fuel is very hard to get and I think it is only 4 star that you can guarantee has none. It's available if you can find a local supplier. I use Shell V Power as it has about the lowest ethanol content and never had a problem with the fibreglass tank on my Majesty, which was made before all this ethanol stuff surfaced. I never used to drain it either, it always had fuel in it.

I think with V power and if you drain the tank after use, you may find your tank won't suffer - but I obviously can't guarantee that, just based on my Majesty tank.

It would be interesting to know if or how they prepare the fibreglass tanks in Spain as many of them use the new reproduction fibreglass tanks, such as the Puma bikes, on the Bultacos and Montesas.

Texaco 'High Octane' is ethanol free (at least for now). Seems to be fine. Previously, using V-power, I drained the tank between events which also seemed to work (but is a bit of work).

[Johnny]

I use Shell V Power in my twinshock race bikes because its 99-100 octane, but they have alloy tanks. I knew that Tesco high octane was also about the same octane rating but I didn't know that it was ethanol free. Interesting- I might give it a go.

On a slightly different note what 2 stroke oil do people use and in what ratio?

[smelling123]

I use Shell V Power in my twinshock race bikes because its 99-100 octane, but they have alloy tanks. I knew that Tesco high octane was also about the same octane rating but I didn't know that it was ethanol free. Interesting- I might give it a go.

On a slightly different note what 2 stroke oil do people use and in what ratio?

Hi mate, Its Texaco not Tesco!

I use Putoline MX6 at 40:1, seems very good.

[Johnny]

Hi mate, Its Texaco not Tesco!

I use Putoline MX6 at 40:1, seems very good.

Been in the garage too long looking at that dial gauge! Cheers

[woody]

Is Texaco definitely ethanol free? Texaco sell ethanol free in the US but not sure they do here.

I thought it was another European directive from those twats in Brussels that all unleaded petrol has to contain a content of ethanol up to a maximum of 5%. It's added at the UK refinieries.

In 2013 that figure rises to 10%. Super unleaded will be allowed to remain at 5% in consideration of the harmful affects to older vehicles...

[pschrauber]

I use Swedish Aspen R (racing) as fuel for the bikes, its a fuel that was invented for forestry machinery like brush cutters and chainsaws. This alkyd based gasoline don't have any ethanol admixtures.

I use this gasoline already for many many years for the chainsaw and brush cutter, expecially because you can store it for years.

They have already a couple of years ago, - don't remember how long, at least five to six years -, developed alkyd gasoline with a higher octane rate. Aspen+ with 95 octane and AspenR (racing) with 102 octane. The racing gas is a very good or even better equivalent to any high octane pump gas you get at the gas stations. You normally don't even have to rejet the carburator, (which you have to to when using Aspen+ f. e., (normal Aspen has "nly 91 Octan which is OK for a chain saw, ..).

This gasoline is also approved for beeing used in indoor events by the FIM.

Benefits:

- can be stored in years,

- don't harm plastic,

- is not a poisen as gas, just unhealthy

- no smoke, very little residues, no soot deposit,

Information about AspenR: Aspen R (racing)

To Premix:

1:40 is very rich, even my KTM MX bike uses only 1:50, the trials get around 1:70,(IPONE or Motorex synthetic).

(Back in the 80's I used Bultaco oil (made by Optimol) in a 1:100 ratio!, sadly this oil is not destributed anymore).

[triple_x]

Hi

My Sherpa has an original Sammy Miller fibreglass tank.

I use any high octane unleaded fuel mixed 50-1 with PJ 1 Silverfire.

So far 30 months after a complete rebuild and used very regulary I have not had any problems.

And whats more no indication of any problems.

Is it urban myth, or, are some tank builders not doing the research and using resins that are not impervious to fuel?

Regards

Martin

[smelling123]

Is Texaco definitely ethanol free? Texaco sell ethanol free in the US but not sure they do here.

I thought it was another European directive from those twats in Brussels that all unleaded petrol has to contain a content of ethanol up to a maximum of 5%. It's added at the UK refinieries.

In 2013 that figure rises to 10%. Super unleaded will be allowed to remain at 5% in consideration of the harmful affects to older vehicles...

Hi Woody, I was told about Texaco (only the 'high octane') being ethanol free but of course wanted to check. My local garage called the head office in the UK for me and they confirmed this to be true - again only for the high octane stuff.

Whether this will be the case for the future...who knows...

Of course, if the tossers in Brussels think ethanol is necesary they must be right - they got everything else right...like the European economy....??!!

The other alternative is buying race fuel, or if you can get it, AvGas is still ethanol free. Some small airports will sell this - its not cheap but not as much as proper race fuel.

[bultaco49]

Hi

My Sherpa has an original Sammy Miller fibreglass tank.

I use any high octane unleaded fuel mixed 50-1 with PJ 1 Silverfire.

So far 30 months after a complete rebuild and used very regulary I have not had any problems.

And whats more no indication of any problems.

Is it urban myth, or, are some tank builders not doing the research and using resins that are not impervious to fuel?

Regards

Martin

Hi Martin

Look inside the tank through the filler cap. The inside of the tank should be a smooth finish with no glass fibre mesh on show. If you can see a whitish mesh then the resin has been etched away and you may not be experiencing problems because little resin is being dissoved now and carried to the carb and engine but ethanol will still be dissolving the resin. In the end the paint finish on the outside will begin to bubble especially at the seams and in extreme cases fuel will leak.

Ethanol problems with glass fiber tanks is a real issue - not an urban myth -. If you don't believe me Google the subject and look at the replies, for example, from the Marine industry and you will see similar forum threads to this and whole reports on the subject from reputable. Here is a link to a good one http://www.boatus.com/seaworthy/fueltest.asp .

It is such an easy task to line a tank. Clean it, dry it and line it then no worries about the issue 'urban myth' or not.

Tim

[woody]

There is ethanol resistant resin, so if new tanks are made using this, they should be fine. I know Shedworks use this type of resin and he has had one of his fibreglass tanks on his Honda for 2 or 3 years now with no problems.

Obviously I'm no authority on this but it is what I've been told and seen.

Interesting about Texaco High Octane. I wonder how they can keep ethanol out of the fuel when the government regulations state all pump fuel must contain it up to a maximum of 5%. Maybe they put a minimal amount in which is as good as ethanol free.