Epoxy, Carbon, Gasoline ???

Aloha Swaylocks crew , I have built a carbon fiber gastank/seat for my GasGas 280 motorcycle ( Trail bike ) almost finished and was wondering if the gas in the tank will deteriate the carbon or epoxy ?? should I line the inner walls with anything or is the material makeup good-to-go ??? Any advice ??

Mahalo Nui Loa , Have a great surf !! Clyde Rodgers Kauai

Howzit Clyde, Making gas tanks now I see. I think if the inside of the tank’s resin is coated with a hot coat it will be ok since I’ve used Gas to remove wax and it didn’t affect the resin finish. If the inside of the tank is just lam resin the gas might affect the tacky resin surface. You should do a test I think. Any progress on that repair board. Just realized you use epoxy and my comments might not apply. Aloha,Kokua

Not sure if this is applicable to your use of epoxy resin as I’m sure they are talking about polyester resin, but the recent switch to using ethanol (E10)as an additive in fuel to help reduce emissions has turned out to be a nightmare for the owners of boats with fiberglass fuel tanks.

October 2006 Issue of National Fisherman has an article on this issue and contains the following quote;

''But if your outboard does pull its fuel from a fiberglass fuel tank, your in trouble and best get rid of the thing.

Alcohol in ethanol dissolves the resins in your fiberglass fuel tank. The tank will develop leaks, and by-products created from the mixture of ethanol and resin will foul the engine, if they don’t create catastrophic damage."

Maybe worth looking into,


Yup, shore 'nuff, gasoline will attack PE resin, and probably some epoxies. Best contact the supplier/manufacturer for chemical resistance information.

Also, you have to be sure the tank interior is well coated, so no little glass or carbon fibers work loose from the slosh, and get into your carb. This too has been a problem with boat owners.


A trial fanatic in Hawai ??? very interesting didn’t knew any people practising it on the islands… it should be amazing to practice it there!!!


Sorry, i didn’t remember the answer…

I teached my father-in-law to use resin and carbon, he used it to modify the official motorbike of his son. I don’t remember exactly he did, but as I remember they were fired from Sherco team because they changed the gas tank, I will ask him to tell me the story again and give you more details (materials, problems…)


OK so I have not been reading for a while… work has been very busy… but something I’ve noticed is that people seem to think that epoxy is epoxy is epoxy…

epoxies vary greatly, and some are suitable for certain applications and other are not. This is part of the reason epoxy surfboards got such a bad wrap for so long. Just grabbing an epoxy and using it may result in terrible results.

It seems like most people here are using epoxies specifically designed for surfboards, which is good for surfboards, but may or may not be OK for gasoline. The advice of contacting the manufacture is the right tip.

—< analogy >—

Saying you are using epoxy is kind of like saying you bought a shirt. It offers a little info but not much. What type of shirt, or in our case what type of epoxy?

—< end analogy >—

Oh and I think part of the confusion may come from the fact that all poly resin is pretty much equal, though not true for epoxy resin.

have fun

Hi, I’m Putxi’s wife. :slight_smile:

I used to practice Bike Trial with my father and brother. Then we started with the motorbikes. My brother just retired last year but he was official rider of Sherco, Gas Gas and Beta… My dad is very good at machanics and he solved the problem of the weight of the tank but the official mark engineers didn’t want a farmer to gave them engineering lessons…

We’ll go tomorrow to my hometown and maybe if he still has the tank he made and other things we can take a couple of pictures for you or at least some advice if you want your bike to be lighter.

You have to use a catalisator, doesn’t you? I remember that my brother had to modify his bike everytime he was at the World Championship in the States or Japan… the bike looses a lot of power…

So, we will see what for tipps we get for you.


I don’t know what kind of epoxy they used, but I put a carbon tank on my Triumph Daytona about 2 years ago, and I’ve had no problems at all.

I’ll email the mfr and ask them, if you want – I can’t promise they’ll divulge any secrets, but…

Wow , Thank you for your response !! Funny wrighting, I think the tank will work ! I’ll let you all know in a couple weeks… Any solid info would be great! We ride mountains, rivers , rocks etc, got old on our dirt bikes! but the trials bikes are the next step forward for us. would be nice to have extra gas and seat for our longer rides !!! thats the reason for the tank…

Aloha , Have a great day ! Clyde Rodgers

Hello Edgefins,

Have you seen Rieju Tango? www.riejumoto.com

It’s so funny, it’s a mixing between dirt and Trial, you can no do everything you can do with a trial but it’s easier to ride. The problem is you can find it only in 125cc and in my opinion it should be a little bit less high to enhance trial capacities.

Don’t have any legal problems in Hawaii? In spain is forbidden to drive offroad … $-P


I was involved with making composite UAV’s, and the ‘wet’ wings we made had the fuel tanks incorporated in the structure. Before final assembly we coated the tank areas in a special fuel resistant epoxy coating, paying special attention to the seams, and fuel and breather lines.

Sorry I can’t remember the name, but this stuff was recommended for solid fuel tank lining, and as far as I know is formulated specifically for fuel resistance compared to standard structural epoxy.

Surfboards? Dunno!! Not relevant I guess.

Thanks for your reply Wildy , There is a tank liner for old rusted worn out tanks, I will do a test with this and let you all know !! I do believe that I do need some sort of liner ??

Aloha , Have a great surf ! Clyde Rodgers

Howzit Clyde,The liner you are referring to is called a bladder.Aloha,Kokua