Fiberglass Fuel Tanks

Hi,
Were fiberglass Fuel Tanks fitted by the factory or are they aftermarket parts fitted later? What are the problems with them apart from them disolving with todays fuels, which I believe can be fixed with the correct resin liner?
I'm not wild about riding a bike with a fiberglass tank in case of an accident, but really how many times have you damaged the tank in any accident? I haven't.
I appreciate any input.
Thanks,
Ian

Ian,
welcome fiberglass factory till 1973.
My June of 72 had fiberglass as orig equiptment.
No sports a nice steeel 1973 set same color.
I ride it regularily.
Marshal

ianashdown said:

Hi,
Were fiberglass Fuel Tanks fitted by the factory or are they aftermarket parts fitted later? What are the problems with them apart from them disolving with todays fuels, which I believe can be fixed with the correct resin liner?
I'm not wild about riding a bike with a fiberglass tank in case of an accident, but really how many times have you damaged the tank in any accident? I haven't.
I appreciate any input.
Thanks,
Ian

Click to expand...

Hi Ian,

If you can find a sealer that works on fiber glass gas tanks against ethanol, you're a better man that most of us who have tried in vain.

Fiber tanks weight less than steel versions. My fiber IS tank weighs about same as steel Roadster tank ~6 lb, till filled up of course. I'm depending on Caswell epoxy thick coat to protect from new gas, so far so good about 4 year with gas in it before drained to repaint. My friend runs fiber HyRyder tanks so fills up at each station passed from rural area into city and back, but so far no yuk into carbs and engine.
His has gas in it for 5 year so far. Thick epoxy sure helps impact resistance too.

Hi,

I had heard Caswell was the way to go. So far good feedback, anyone want to add a comment?
Ian

hi there, im in the middle of rebuilding my interstate tank stil, have it all sanded and channels rebated on extrenal joins for re attaching the 2 parts, just gotts vinyl ester coat it all over and then il be using caswell on it to, ive got it all here just trying to find some more time, will post pics when done though for all to see.
The interstate tank has a hollow in the bottom, i was wanting to drain the fuel each time when it sits but if u look at an interstate tank side on from the inside as standard they cannot be fully drained as some will always sit in the bottom, i was thinking of filling this up so it all can be draining when needed.

Adam

Ian... do yourself and the world or drivers a favour and give your fiberglass tank to some genuine article collector type who needs the real thing for say a concours restoration. There was a very good reason they were made illegal for production back about "73" , fiberglass shatters upon impact sending atomized gasoline all over coils, h.t. leads and hot exhaust pipes ,whereas metal prefers to crumple and retain the explosive liquid in the tank. Spend the money and feel secure.

Caswell and all the various products have had mixed results as far as I can tell. This may depend on application techniques and prep but I'm sure nearly everyone who has used it thought they were doing the best job they could following directions. Check the archives.

I also went to a metal tank. My original tank is in the rafters waiting for better technology or maybe the dumpster. As mentioned in one of the recent threads on this, it is not the best idea to invest in a really expensive paint job on a fiberglass tank. I did -- like an idiot.

yeh batrider i agree after i finish repairing my fibreglass tank i wont be repainting for a while, although i cut from underneath so minimal repair is seen there is one spot i have to fix ontop, but il just be using it as it is too see how it all holds up before paint! Steel tanks are always gonna be superior though.

I invested in a high end paint job, I'm crazy like that. But I did line the tank with Caswell and had excellent results. Getting it right has more to do with the application process in my mind. My process worked like this - Fill tank parially with 100% gasoline and throw in a few new nuts/bolts...shake vigorously...drain...repeat. After letting it dry for a few days mix the caswell and pour in, swirling around constantly to get coverage all over the tank, let sit for a few minutes and check for pooling in the bottom of the tank, when it appears swirl it aournd again to re coat. After everthing was applied (and this is were it gets weird) I tape a garbage bag to 24" fan so that the bag inflates when I turn the fan on. Then cut a corner out of the bag and tape it to the fuel inlet creating a funnel that forces air through the tank venting out of the petcock holes. I let it sit like this for 36 hours or so, end result was a nice hard coating covering the entireity of the tank. This was probably 9 years ago and it's still in excellent shape....so far so good.

Oz -

I think cutting the bottom out like you and jeandr did would be the way to go to have any chance of it working. I have 2 fiberglass tanks - my original yellow gelcoat tank (untreated) and an orange one I had coated (2 treatments with Redkote) by the expensive painter. I didn't have the dissolving problem with residue in the carbs on either tank but the painted one has developed a bit of orange peel look from underneath the clear which wasn't there when I got it. I just don't want to take the chance and ruin it further. I have not detected any softening. So maybe OK maybe not.

I drain my tanks every winter and even take the petcocks out and leave the cap open so whatever might be in there will evaporate. I have a local airport which will sell Avgas (no Ethanol) to bikers. This is fine if you stay close to home but I don't always do that.

68 - 9 years is pretty darn good!

Russ

Russ - I guess ur lucky as yours havnt bubble right through yet it would appear, although being uncertain if there ok is maybe more worrying. Yeh I like ur idea of draining it that's what il be doing everyride I think, well maybe not in summer, if I can find a cheap steel tank though I'd grab it in the blink of an eye but I'm curious to see the results of the vinyl ester and caswell job I do

I love-hate the picture of shrapnel fiber glass tank enveloping a rider in a blaze like 911 fuel explosions. I see that in the movies a lot so its entirely possible.
But I've fractured off stem stop so to smash fork into front of IS tank and landed on rocks into fiber tank and also bent headsteady sideways on a friends HyRyder tank so a bolt punctured from inside. Both tanks had thick Caswell epoxy inside and did not shatter but through gel coat and few layers of splintered glass only my friends leaked later but JBWeld stopped that. So thick epoxy coating seems to stifle the dramatic fire balls and strengthens a good bit to boot. Seriously you could make a whole tank out of just the epoxy coating, if done in layers like ya should anyway. Tricky vital area is cap rim inside and out.


Acetone is what I use to clear insides in prep to coat as it dissolves old resin surface and what ever else might be adhering to prevent full bind of epoxy. I set hair drier on low in filler hole with pep cocks removed for a day and night. Or till I can't smell it no more. I run greased wood dowel into taps and beyond.
I turn tank for at least 30 min each coat or just short of getting excess to drain out then flip it around for another hour or so intermittently till about set up.

I'd like another fibre IS tank for my steel tank Roadster, I ain't least bit afraid of them but sure do appreciate them for gripping with knees and big tank bag.

I had a Dunstall F/Glass tank on a Meriden Triumph twin in my youth and it split like an egg cracking, dropped a tank of fuel on a hot engine when I was doing 110mph. The fuel evapourated in an instant leaving a cloud behind me and my jeans (no protective clothing in those days) were wet with fuel. BUT IT DIDN'T IGNITE SO I AM STILL HERE.

This was before they were banned because they went 'big time' without warning whereas a metal tank would get metal fatigue and hairline cracks and start to dribble first, plenty of warning.

Nowadays, many manufacturers use Plastic tanks, Triumph included, but they must have past strict safety regulations and I think they are layered with polythene layers embedded within the plastic like rubber bags that contain the petrol even if you took a hammer to the tank and smashed the plastic.

The early tanks were banned for good reason so you want to line it with something that contains the petrol if the tank cracks or or the tank takes a blow in an accident.

You can get some good re-manufactured steel copies nowadays. When I was young I thought I was immortal but now I know that I am not. :roll:

Those horror stories must be brand specific in construction short cuts as I've crashed hard a number of times on sides and top of IS fiber tank w/o any bad effects, even upside down with tank only held on by the two front studs. I expect the mass leverage on those 2 studs to be the weakess spot but they even fork smashing front in just fine. Fiber tanks were pretty standard in slam bam boat and aircraft. Then the new fuel did em in, just like us, until epoxy coated well. Ping me on unwanted Interstate obsolete fire ball gas tank. I seek 2, one for my steel Roadster and another [unrecoverable-repairable] to put my ashes in.

BTW you can not ignite gasoline vapors/fumes by any thing but almost white hot temps from open flame or electric arc or stone/metal spark. Exhaust flame jets can of course, but no way can a cigarette or glowing bright red ember blown on to in white cloud of gas as I've tried to get a fire flame going again, then stepped back a ways to toss a match out for KaWHPOOFF in the air/fuel explosion.

Fiberglass tanks blow up real good. Myself I plan to kick the bucket riding a Royal enfield 500 Bullet in India this wintertime, south to north, no kids,you can all have my Norteroonies should this occur . Pleeese do not drive with a glass tank , lost a pal in Ottawa before the legal changeover, (also Cliff on his H2 on Merivale Rd. stunting race). Steel , aluminum. Pleese.

My heart relates to lost friends on motorcycle. I know it could be me or anyone.
i came rather close to burning on deer strike that trapped my boot under still runing Combat with gas draining out on point ignition and I couldn't reach key or hold kill long enough to kill it.

I would like to know how the fiber tank was involved in the death.

Mythbusters did the thing with the cigarette on gas and it did not light. Gasoline does not explode, it burns, gas without air will not burn... The fiberglass tanks were outlawed because there were accidents, some cases involving a gas spill and a fire ignited most likely by steel parts giving off sparks as they screeched across pavement. I am sure there were instances of the same thing happening with steel tanks, but what can they do about it?

There are a lot of dangerous things one can do in a day, starting with getting out of bed, so I will coat my glass tanks, use non ethanol fuels if possible and stop worrying about it.

Jean

Amen Jean, first risk is leaving bedroom then goes way up just getting on a bike then exponential risk rise once actually riding it. Its twists my mind to the heart roots on warning attitudes for safe sound riding practices and equipment vs kicking up one heels with what ya got where practical to get away with it repeatedly.

I just can't imagine how an exploding fiber glass or steel tank has much to do with riding injury, as too well can remember and see images of such crashes over whelming rider's life weather burning or not. I mean really do we expect a cycle to smash into a car so hard it traps people inside with a fire ball? I mean really do we expect to survive an impact so bad to explode tank that leaves riders any where near the bike when it lights off?

I my best friend & cub scout mate with too much ego fell off playing on highway and did fine till his head run got over at age 14, though took some hours to expire. Lost a couple less close friends I'd met on the road - almost daily emailing for a few years, often putting me down for being such a risk taker, then their family notifies his list that they got wiped on on motorcycles no fault of their own.

So I'll take the exploding gas tank if I ever plant my face deep into a truck grill thank you or get squashed under wheels. Should make for great front page photo. Hope I don't uspset list but I'm pissed that life is so short and frail and painful at times, so out to have fmy un to share with others while we can and maybe leave something others can enjoy after me.

Great photo Hobot ,I have one of my 73 850 burnt to a crispo with firemen standing about the smouldering cacass. Photo in slide collection must learn how to post it. ? As for demise of riders heard of event on Hull side of Chaudier bridge , Ottawa,way back say 1972 ish ,collision with car , glass tank norton lost , not a pal just talk amongst our small group of concerns etc. A year or so later Cliff put his H2 Kwackersaki into a car , Merivale Rd. right near M. high school , stunting with 2- stroke powerband wheelie. H2s and H3s disliked front wheels on pavement. As for glass tank thread ,drove my 70 S for years there , no probs ,learned they actually take a small hit better than steel which will bend in using same force. Take note early tank gascaps flip out towards rider, later ones away in case of collision and cap popping open to not spray rider with atomized fuel !