Gas Tank Repairs

[Brian Stevenson]

My RZ 350 tank split along the seam top to bottom on the left hand side. Its pissing gas out everywhere.

Will it pass tech if I just wrap all the seams in Carbon Fiber and bond it with a Phenol Novolac Epoxy (I'm hoping that Pat Cowan will chime in here). Not sure if its period correct though.

There is absolutely no way you can weld that unless you have a proper seam welder, I'm just wondering if anyone has access to one.

[Brian Stevenson]

Just another question. Is a plastic tank permissible?

I know some Ducati's have plastic tanks and I assume they are allowed to run with them. The TZR125 tank will bolt on but its plastic. Will it pass tech?

Having re read the rules it doesn't say you can't run a plastic tank. I don't suppose its any worse that Fiber Glass.

[pacomotorstuff]

Hey Brian,
Just saw your post. I assume you're talking about the RZ tank seam on the left hand side, towards the back of the tank, where they all seem to collect water and rust out.
As far as fixing the leaks, I'd suggest as a first step, follow the Caswell instructions as regards cleaning the inside of your tank and do a complete tank coating per the instructions except... don't pour out the excess resin. Because you're not trying to save the exterior paint job (right?), seal up the rusty seam on the outside with duct tape or aluminum tape and tilt the tank to let the excess resin sit in the problem area and gently rock the tank back and forth, so you're coating the seam and the resin will fill the area as it cures.
There is a certain amount of caution here; the Caswell coating has an extremely exothermic curing cycle and produces A LOT of heat and indeed can start a fire if you're not careful. Have a bunch of old towels / rags / whatever soaked in cold water and if you feel the repair area getting hot to the touch, lay the wet rags over the exterior of the tank.
If you think an external patch is required as well, don't use carbon fiber (for a bunch of reasons). Use fiberglass cloth (not mat), maybe 3 layers staggered size and make certain the repair area is operating room clean before you attempt the patch.
It's true that repair failures are almost 100% due to poor mixing of the resin components or poor cleaning of the repair area.
BTW, might be best to do this outside and have a fire extinguisher or a big bucket of water handy.
Pop me a PM if there's anything else.
Pat

[Brian Stevenson]

Thanks Pat. This is great information. I'll send you a PM but why not Carbon Fibre? I thought the twill would form around the seam better than the fibreglass cloth.

I may end up going with the 1st gen R6 tank. If you cut out the mounting hole for the gas cap and 2 inches out of the middle and weld it back together it will fit on top of the RZ frame rails. Its only about £100 so if I can find a solid tank in the UK and then have it shipped after its done it would probably be cheapest. I would have to weld a small bracket into the RZ frame for the front mount though.

I'm also on the lookout for a TZR tank that just bolts on and its plastic or a TZ250/350 G tank that is also close but just needs a few brackets changed.

Its not a restoration so any of these will work