I bought and fitted a second hand carbon fibre 916 fuel tank in the summer. Unfortunately it’s spring a leak from where the fuel pump base plate mounts. The workshop have reported today that the reason it is leaking is that the resin around the rim has been degraded by the fuel and is crumbling away. See pics (hands belong to Ray Petty). Thankfully it was only a dribble of petrol but looking at the pics it could easily have been a flood followed by an inferno. Any recommendations for repair or just chuck it in the bin and buy a new one? Thanks
www.tankcareproducts.co.uk tel.07834415921 Give these a shout. Let us know how you get on. I like a bit of carbon fibre tank action so I took note of these lot just in case
Looking at that picture, the flange that the pump ring bolts down on doesn’t have much meat, and looks very resin rich. potentially the vibrations and use its had together with successive tightening up cycles would have only stressed it further until it just gives up as theres no real carbon there to reinforce the matrix. you can get that repaired easily and reinforced rather than throw it away. after that use por15 or whatever their latest and greatest product is to seal it as best you can.
Andy, get some metal putty, (I’ll dig out the name tomorrow), fill and reshape the gaps. I had to do similar a while ago on mine. The putty stuff works perfect even submersed in petrol. I also had to make and fit a new fuel pump fixing for the fuel pump flange and metal putty worked a treat for that too. Ian
Thanks mate. I know the stuff you mean and have some in the shed. I’m having RP refit my steel tank for the moment and may have a go at doing the repair myself when I get it back from him.
Just text you the info mate. If you want, I’ll pop round next time I’m down. Shouldn’t take more then a couple of hours
That’s really kind - I’ll WhatsApp you. I’ve repaired stuff with chemical metal before but never anything which contains several gallons of petrol and is in close proximity to both my family jewels and a red hot exhaust manifold, so if I do end up doing it myself, a bit of supervision/assistance would probably be a good idea
Is this chemical metal certified ethanol proof? What is it called as I think I'd like to get some! POR 15 tank sealer says on their webpage that it is "NOT suitable for plastic or fibreglass tanks". https://www.frost.co.uk/por15-basic...FvC5agQ_IXCBgzqNTrQDp7uOrE2ERJTUaAnDqEALw_wcB
I’ve not checked what I have in the shed yet. In any case, if I don’t get a professional to do the job, I’d definitely be checking whether it’s petrol proof first and even if it is the right stuff it’s a good few years old now so I’d buy a fresh tube anyway. @bettes ? @cookster - I’ve heard back from Target. Unfortunately they said their insurance wouldn’t cover working on fuel tanks. @Mary Hinge - I’ve contacted Tank Care and am waiting for a reply.
If you do decide to replace, just get a beater aluminium tank, who are the daddys of the Suzuka 8hr and endurance fuel tank. The cost will be on par if not cheaper than a carbon one and you won't have the associated headaches and the world of hurt that is a carbon fuel tank bought by civvies. The problem you have with your tank is that it's a wet lay tank probably of nearly 20 years vintage and that fuel ring area is heavily resin rich. - And you don't know the resin system whether it's an epoxy or polyester based item. You're going to bodge paste one bit of it and down the line more will crack off. You'd be better off going to a composite manufacturer and getting them to take a mould of the area, and make a nice new pre-preg ring that they can graft on. The other option you might want to consider is to make a new ring entirely from alloy, drop in in there bonded in place and your filler cap bolts into this. In fairness it's probably the route I'd look to if I can't get a piece laminated to go in there. Yes your pump mounting plate might sit a bit higher by a mm or two but all said and done a rubber ring and some foam can hide that. You might want to talk to these people regarding the sealing matrix: https://www.masterbond.com/products/polysulfide-adhesives-sealants-and-coatings It's not at the point you have to consider dumping it, but new or used, it's a road bike it's going on and that opens up several other things you have to consider relating to the upkeep of it.
Thanks Sev. I really appreciate all that advice. I’m now in discussions with a couple of companies which specialise in CF repairs, they’ve seen pics and they both think it’s viable
I dealt with a Kawasaki ZX10 tank small leak a number of years ago.....it was seeping from a bottom seam, so I emptied the tank, filled it with boiling water/fairy liquid mix, gave it a good shake about and let it stand, until it had cooled down. Turned the tank upside down and silver soldered the leak using a small blowlamp. Touched up the paint with a brush. Mind you it was a metal tank, not carbon fibre. Which is why it is obvious I posted in the wrong thread
just emphasise that if possible you want to go back to the carbon. That milkyness you can see in your picture on the tank ring is a thick slug of resin, and it's that which is breaking off. It's brittle so any little stress on it will cause it to fracture over time, and repeated heat and vibration cycles won't help. Whoever you get to do it ideally should reconstruct the area and give you a solid seat onto which to bolt your filler down onto. Even if they cut a ring out of carbon and bond it in it will be better than what's there at the moment.
