How to clean a gas tank?

How does one go about cleaning their gas tank? I picked mine up today and shook it (it's bone dry) and it sounds like theres about 1/2 cup of dirt rattling around in there!

Here is what worked for me.

I took off the fuel petcock and covered the underneath opening with a few, good solid strips of duct tape. I then put in around 3 pounds of roofing nails in the tank and rolled and shook the tank around for about 20 minutes. The weight and abrasiveness of the nails will scrub off almost all of the surface rust without damaging the good, solid metal. There is always one of two nails that are a pain to get out but an extended magent will grab the last few stubborn ones.

I then flushed out the tank several times with gasoline, rotating it so the gas is getting all around the bottom and top of the tank.

If this doesn't solve your problem you can put in a 3 to 1 mixture of hot water and muriatic acid. Don't fill the tank more than half full with this solution.

The petcock opening and gas cap opening will have to be covered in duct tape to seal. You might want to leave a small opening in the cap opening for offgassing of the solution. You will notice the bubbling action which signals the acid is doing its thing.

Let the tank sit level for about half an hour then rotate the tank very slowly as not to splash any of the water/acid on your paint job. After draining the water/acid, flush with gasoline several times. Most of the crap is in the bottom half of most gas tanks but the slow rotation will remove any rust on the upper sides.

Wear rubber gloves, safety glasses and keep a damp rag handy in case you spill any of the water/acid on your paint.

I just did this last month and the tank is perfect inside. Just to be certain the tank would stay clean I put a thin coat of "Red Coat" fuel tank protection inside the tank. It is like a urethane syrup that never fully hardens. I have been told by an industrial fuel tank/rad shop the Red Coat is better than the Cream.

Cheers-Colin Firth=Ontario Canada

'77 Kz 650 Custom - (Miss July on 2006 Kzr Calendar-with last year’s restoration and engine project, a Wiseco 700) Newest rebuild includes Wiseco 810 kit, Kz750 cams, Kz750 intake valves, 750 GPz springs, Ported head, WG Mikuni 28's, Velocity Stacks, Dyna Ignition and coils, MAC pipe, 14 tooth front sprocket. Returning to original '77 Moon Dust Silver. Goal is to have a stock-looking, ultra-sleeper bike that will tighten up any loose dental fillings off the light and surprise other, bigger bikes.

Check out our filebase, there are a couple ideas on how to do this. Here is a link to the one I wrote up

kzrider.com/component/option,com_docman/.../gid,248/Itemid,231/