Any reputable auto parts store
You buy a new one
From a salvage yard.
buy the gas tank
In the gas tank In the gas tank In the gas tank In the gas tank In the gas tank
When searching for one to buy, I have found that this model has an 18 Gallon tank. And you have to fill it with Premium Gas so the engine perform properly.
Get a 2 litre valve tank with coatings on the in side look on eBay there as cheap as £4.00
Your local welding supply store should have nitrogen tanks, or know who your local compressed gas supplier is. You will most likely need to pay a significant tank deposit, and purchase a gas regulator for the tank.
To my knowledge, most gas grills do not come with the propane tank. Most tanks can be bought for about 40.00, and filling it each time will set you back about 25.00(depending on the price of propane).
Tank has water in it. Gas floats on water so when fuel level gets low enough it sucks up water. If you are having trouble at 1/2 tank then you are beyond using dry gas. At this point you must remove and drain tank. I also suggest changing where you buy gas!
You need to decide on capacity then buy tank and hangers and a selector valve ,fuel lines, sending unit.
Buy a new or used tank.
Depending on what you mean by repair. If there is hole in it then no you need to buy a new one.