Carbon tanks melting?

L

Ludi Boba

Hero member
When making motorcycle tanks, Carbon Fibre, Kevlar  and Glass fibre are materials used to reinforce resins.
So when a tank gets dissolved by modern fuels it is resin to blame not the reinforcing material.

Two most common resis in use are the Polyester Resin and the Epoxy Resin.

For some time now, I have been repairing and remaking some older aftermarket tanks that dissolved under the influence of modern fuels. These were mostly seventies products , Dunstal, Gus Kuhn, Bimota to name a few but these were all made in polyester and glassfibre.


Look inside your tank.
If the material  it is made of looks like randomly spread fibres, not woven, than your tank has good chance to be dissolved. This material is called chopped glass mat and is always used with polyester resin. Polyester resin is not resistant to ethanol.
Most of seventies tanks were done like this.


On the other hand the Epoxy Resin has high chemical resistance. It was not so commonly used because of the price.

For my work I only use Epoxy Resin.
When my first piece was made took some cutoffs to a lab. They held in concentrated ethanol for two months and tested the ethanol for traces of dissolved epoxy. The result was negative.

Questions?
 
You can always line the tank with Caswells to be sure to be sure.
 
Davo said:
You can always line the tank with Caswells to be sure to be sure.
Click to expand...

Davo,

Just Googled Caswells. This is also an epoxy resin.
And it states that it is used for repairing steel aluminium, fiberglass and plastic gas tanks. Guess by fiberglass, they mean fiberglass reinforced polyester. Do not know about others but epoxy and polyester resins do not bond well.
 
Epoxy is used commonly for repair of polyester resin boats as it will stick well to polyester but never the other way around ie polyester does not stick to epoxy which is why people in general think they are incompatible. The polyester has to be scrupuously clean though hence the cleaning processes and preferably rough sanded which is not possible inside a tank.
 
Boba,

I really like the workmanship that comes out in the pieces you are producing, and just hope that you are suiting up well when playing with CF and Vinylester epoxy.  I have a lot of friends in the yacht building game using it, and they are on 3 monthly blood tests, same as some spraypainters do.  I used to wear the old white 'sperm' suits, taped to shoes and gloves, with mask equipped with pre-filters, then particle, gas and another pre-filter.  Some of the younger blokes use to laugh, but not any more - you get used to being a bit hot in the gear and having a 'snout' on (or, even getter, the fully enclosed hood to fully protect earsd and eyes as well).  Remember to look at your skin as just another filter... things do pass through it and into your body.  The jury is still out on long term effects of exposure to epoxies and CF, but I know quite a few who are unable to work with them anymore due to the effects of being exposed.

That being said..... beautiful, beautiful work!

Yogi
 
Ludi Boba said:
When making motorcycle tanks, Carbon Fibre, Kevlar  and Glass fibre are materials used to reinforce resins.
So when a tank gets dissolved by modern fuels it is resin to blame not the reinforcing material.

Two most common resis in use are the Polyester Resin and the Epoxy Resin.

For some time now, I have been repairing and remaking some older aftermarket tanks that dissolved under the influence of modern fuels. These were mostly seventies products , Dunstal, Gus Kuhn, Bimota to name a few but these were all made in polyester and glassfibre.


Look inside your tank.
If the material  it is made of looks like randomly spread fibres, not woven, than your tank has good chance to be dissolved. This material is called chopped glass mat and is always used with polyester resin. Polyester resin is not resistant to ethanol.
Most of seventies tanks were done like this.


On the other hand the Epoxy Resin has high chemical resistance. It was not so commonly used because of the price.

For my work I only use Epoxy Resin.
When my first piece was made took some cutoffs to a lab. They held in concentrated ethanol for two months and tested the ethanol for traces of dissolved epoxy. The result was negative.

Questions?
Click to expand...

I think that this explanation was very useful as resistance to ethanol of your fuel tanks is surely the most common question. Thanks for that.
 
To prevent these dissolving problems, is using premium grade fuel a solution? My local gas stations (here in Saskatoon, Canada0 have assured me that there is no ethanol in their premiums.
Dennis
 
Dennis, don't forget the oil companies can change their formulations at any time. They don't have to ask for or wait to be granted permission by any governmental agency (maybe not in Canada, but that's sure the way it works in the US), they are free to go with what's most economical at the time. Ethanol is quite expensive to produce with the transportation and manufacturing technologies the oil companies use here, but there's been a HUGE federal government subsidy used to reduce US dependence on foreign oil by using ethanol for about 5 years now.
The White House has announced they're going to discontinue the subsidy. Petrol has got a little cheaper in the last month or so, but it's still more than twice what it was a bit over 2 years ago, and the oil companies have been making record profits during this time. A meeting between the president and a group of major oil company executives a bit over a month ago made it clear the oil companies were not going to show any restraint (despite the global recession) and were going to continue going after every last cent they could get.
How that translates to what you'll see in Canada is hard to predict, but it appears ethanol in petrol is probably here to stay. We don't get any say in where it shows up, and we're lucky if we even know when it appears.
I should buy ethanol-free petrol from an independent supplier (not too hard to find here), but it's too dangerous to store any significant quantities in the garage.

Ken
 
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