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Discussion Starter · #44 ·
I agree, reason why this gas tank will only be a positive mold ( It's not from this bike anyway, so it doesn't have to be 100% the exact size) for a carbon fiber copy, well the fact that it's lighter and the carbon look, I'll just varnish it satin or matt.

First time ever last w.e on my car as a test:



Encouraging for a first time...

I'll do some other small parts before the fuel tank.
 

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Number one reason why Steel is the worst material to make a gas tank out of. Rust.
... number 2 reason is weight.
Gotta disagree with you on that one.

As any one who owns a bike with a painted plastic tank knows (Ducati and Aprilia I'm looking at you), PLASTIC is the worst fookin material to make a gas tank out of. It's not a question of IF it expands but WHEN it will expand.

I will not consider owning certain year/model Ducatis simply because they have plastic tanks. The tank on my RSV trackbike didn't fit the bike anymore because of how much it had swelled, so I replaced it with a steel tank from an earlier bike. Steel can be fixed. Plastic just sucks. And fiberglass/carbon fiber on a streetbike doesn't thrill me either, I don't trust the resins used to hold up to the various crap they put in gasoline these days. Drain the tank whenever you're done riding? Get the fook out of here.

The aluminum tank on my 851 has it's own issues but it's probably my favorite tank material. Steel is actually my second choice.

Full disclosure, my current Moto Guzzi also has a plastic tank, but it's hidden under cosmetic panels. That's a different situation (though I plan to sell the guzzi next spring anyway).
 

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I'll reference you to Geeto's trials and tribulations with his sportclassic
 

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lol wtf you bringing up painted plastic tanks for, Aluminum is the material of choice. They even make airplanes out of it. Titanium parts are nice too if you have really deep pockets.
 

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Hey, you started it with your "worst" rating! :p

I thought about titanium... it's been a lot of years since I worked with it and I never knew a ton anyway, but I'm guessing stamping titanium is a bitch, wears tools quickly, and is a pain to weld in production so not a great choice for tanks.

They made airplanes out of plywood too, doesn't mean it's a great material for a gas tank!
 

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Titanium makes for a very nice 2-stroke exhaust system, if it will hold exhaust gases it should hold gas.
Carbon fibre is great for a shield to protect your expensive light alloy parts. or a helmet.
 

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Gotta disagree with you on that one.

As any one who owns a bike with a painted plastic tank knows (Ducati and Aprilia I'm looking at you), PLASTIC is the worst fookin material to make a gas tank out of. It's not a question of IF it expands but WHEN it will expand.
Yep - the Aprilia Dorsoduro had/has a problem with the expanding plastic fuel tank. Haven't had any problems with the Shiver 750, however it is always covered and garaged and rarely has a full tank - don't know if that is a factor. Maybe it was/is a venting problem with the DDs.
 

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I work with carbon for a living and know the stuff inside out, I really wouldn't recommend it for a fuel tank, there are various issues with it, UV degradation being one, more to to with the resins involved.
The resins start to break down over time and turn green / yellow, obviously painting it can protect it to some extent.
And you may need a liner inside, carbon can be porous too as it tends to have tiny pin holes.
It can and has been done though, an autoclave would give the best results but that's mega money!
 

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It's a weave yes, but it's filling the weave with the resin that's the problem, I use various silicone bags made to suit the moulds and infuse the resin via a vacuum to pull the resin through the cloth.
This in theory should remove any air from the weave and fill it with resin, I still get some tiny pin holes on occasion, warming the resin with a heat gun as it travels through the mould helps as it thins the resin and expands the air bubbles to get them moving.
 

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It's a weave yes, but it's filling the weave with the resin that's the problem, I use various silicone bags made to suit the moulds and infuse the resin via a vacuum to pull the resin through the cloth.
This in theory should remove any air from the weave and fill it with resin, I still get some tiny pin holes on occasion, warming the resin with a heat gun as it travels through the mould helps as it thins the resin and expands the air bubbles to get them moving.
Thanks for the explanation. Appreciated.
 
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