Glass fuel tanks Myths and facts

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May 22, 2004
Hi blokes

Has anyone got thoughts on fibreglass tanks..

I have two issues here~ OK

I for one have been hunting a fast back combo , but ti has been suggested that the early / original f/glass tanks are extremely dangerous and or prone to deteriotion which cannot handle the fuels of today as it were ~

The question I ask . Do the tanks deteroiate ~
(Same question could apply to crash helmets here too !)

I know there were incidences of fuel tanks back in the 1970s ~ and bans .. but TODAY `how much of this is more Myth than fact !?

Can glass tanks or do they need to be treated to preserve them ~ and if so ~ with what ~ ..

I have never heard of tanks splitting or exploding in Australia ~??

I personally think the hysteria against fibreglass tanks has been blown out of proportion. Yes, they can and do develop cracks. I've been told the additives in our modern petrol dissolves the resin, gumming your carbs. So I guess getting it lined would be a good idea. But splitting or exploding? I'm skeptical about that. Has anyone ever actually had that happen? I suppose it's possible for the tank to rupture in a violent collision. But that may be the least of your problems in that situation.

I have two glass tanks. The one that came with the bike was cracked and leaking so I patched the leak with a fibreglass repair kit from the car parts store. Then I had the tank professionally lined. No further problems.

I bought the other tank off ebay to use while getting the first one fixed. It had never been lined, did not leak, but gummed up my carbs in a few weeks. However, I did not clean it out before use so the gumming may very well have been from old fuel varnish in the bottom. Live and learn. One of the guys in our NOC has a very nice original glass tank on his bike. It's unlined and he's been running it like that for years. He feels lining is unnecessary unless the tank is leaking. BTW we have oxygenated fuel with ten percent ethanol here. I don't know what to think about lining vs not lining now.

On the positive side, the glass tank will never rust or dent! And they don't have that ugly welding flange. And you can pick them up (relatively) cheap because everyone is so desperate to get steel tanks. So I'd say don't panic :)

I'm sure others will have strong opinions on this...

I think Debby was spot on in using the adjective “hysteria” to describe peoples perception of fiberglass gas tanks. I’ve used fiberglass gas tanks up into the late 90s and never experienced any problems.

Notably, fiberglass is often used to construct fuel cells for homebuilt aircraft. I have a friend with a homebuilt Corsar that he flies regularly. The fuel tank is fiberglass and he has never experienced any problems with it. What ’s more, fiberglass is often used to construct tanks that are designed to safely contain all sorts of caustic liquids.

However, as a cheap insurance policy, you may want to line your tank. I used Bill Hirsch liner on my spare tank. Reportedly, it’s designed to work with fiberglass; many tank liner products are for steel only.

fiberglass tank


I put a fastback setup on my roadster for this season. So far no problems. It was previously lined, but I can't tell you with what. It's nice to have 4 gallons of gas instead of 2.5 (I checked the capacity filling it from completely empty). This is on a '72 so the roadster tank is also fiberglass and was lined by Ken Armann.
Question for Jason

Jason, where do you buy or purchase the Bill Hirsch liner ??? Is it something that one can apply themselves?? Appreciate any info. semper fi devildog
"I put a fastback setup on my roadster for this season. So far no problems."

illf8ed ~ I used ~ USED to own a LR Steel tank ~ and all the fittings.. (break out the violins here! ) But I sold the lot for $500 aud at a swap meet ..part of a separation :cry: :cry: ~ for the sale that is . :cry:

( the guy ~ a MC journalist ~ nearly fell over himself to scrap up the 'dough' .. he was riding a avery tidy Norton Rotary on the day , also a apart of his 'stable" ~ )

Surely the new Norvil tanks for example would be a 'complete package " ?
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