Kz1000 Carbon Fiber Fuel Tank

DISCLAIMER

THIS THREAD IS FOR INFORMATIONAL PURPOSES ONLY. ANY PARTS BUILT OR MODIFIED USING THE PROCESSES SHOW ARE FOR USE ON OFF HIGHWAY VEHICLES ONLY AND SHOULD NOT BE USED ON VEHICLES OPPERATED ON PUBLIC HIGHWAYS.


Fellow Kz riders, in this thread I propose to duplicate my stock 1978 Kz1000 A2A fuel tank in carbon fiber. I do not undertake this endeavor lightly. I believe I understand the downsides to having a carbon fiber tank and I am willing to accept them. I separated this thread from my sidecover/tail thread to make it easier to search and find, rather than readers having to wallow through the other thread. But if you are interested in reading it, you can find it here:
kzrider.com/index.php?option=com_kunena&...ew&catid=6&id=380084

I will be prepping the stock gas tank, then making a mold of it. Once the mold is completed and prepped I will laminate the parts. There will be two parts to the tank, a top and a bottom. The two parts will be joined by epoxy adhesive and the interior lined with a liquid sealer. After making the molds for my sidecovers, I had an idea on how I would do the tank. It involved making the top and bottom molds, with the top mold being a 2 piece mold. Then I ran across a thread on another forum found here www.bayarearidersforum.com/forums/showthread.php?t=145975
After reading through it, not only was I convinced my original idea for the mold and tank construction was sound, I was certain I could pull it off!

And with that, let's get started

Here is my stock green tank

It has some blemishes in the finish that is unaceptable to mold off of, besides I need to cut off the neck flush with the top of the tank.

I also needed to remove the painted stripes as well as feather out the chips/scratches in paint. We'll need the tank to be as straight as possible so that the mold is as perfect as we can make it. Otherwise, any defects in the surface or the lines of the tank will get transfered to the finished part. We strive for perfection

I sanded the tank with 220 grit and a DA sander, painted trim stripes removed, the filler cap mounting tabs removed and ready for the next step.

Using a die grinder with a cut off wheel, I removed the top of the fuel filler neck.

I finished it with an angle grinder flush with the top of the tank.

I discovered 4 dents while I was sanding, ground them down to bare metal and spread on filler

I was LAZY and I didn't feel like mixing up body filler, so I used straight spot putty. Spot putty isn't designed to fill large or deep areas, and as a consequence, where I spread it thick I got some shrinkage cracking

THATS what I get for being lazy :laugh:

you slothful lazy man

Tell me about it!!! Where it's cracked from shrinkage, I'll have to remove it back to the metal since it won't have cured properly underneath. Three of the four dents I'll get away with though, so maybe it was worth it after all :huh: Once the dents are filled, I'll flip the tank over and coat the underside with paint remover. The underside of the tank has ribs from stamping that will unessasarily complicate to layup, so our solution is to fill them in to make the underside smoother and therefore simpler to mold off of.

Maybe a heads up, if for street use you may want to check the laws for this. Even racing they may have rules that may be against a otherwise neat Idea. Bursting, then fire when hit?

Please, please, please check the laws where you are and in other states.

I know fiberglass tanks are illegal many places.

Thanks for the heads up motorhead. I considered the crash scenario before deciding to go forward with this. It what I mostly meant when I said I believe I understand the downsides to a carbon tank, and I am prepared to accept them. I am going to have several layers of Kevlar in the laminate, to help mitigate the more brittle nature of pure carbon fiber. The bottom line is yes, if I crash, I run the risk of bursting into flames and burning to death. I accept that possibility. As far as Johnny law is concerned, I'm sure it probably is illegal, but isn't everything that's lots of fun? If I am going to get a ticket for an illegal tank, I'll probably get written up for a bunch more than that. On a positive note, I have never had a deputy look at any bike I was riding. They write the ticket an run :X

I know it would kind of be cheating, but you could just cover your tank with kevlar like RoyNor...you could say it was the responsible thing to do.