Do you lose gold and elixir in clan wars?

I think you're asking whether or not you should set up your war base to protect your storages and your collectors.

The answer to this question is no, there is no need to do so. If an enemy attacks your war base, your resources in your "normal" base are unaffected.

There is a small amount of resources in the war base storages, but these are not taken from your normal base. They are made up from thin air for each attack on your war base.

As far as the other question of "will you lose or gain resources for participating in a clan war" - it depends on whether your clan wins, what you attack, and how efficiently you attack it.

You will always profit gold from war win bonuses, because there's no gold cost for any army training.

You can often profit elixir and dark elixir if you're careful, but it is also very, very easy to train armies more costly than the war win bonus. The war win bonus isn't calculated based on the amount of resources it would/should take to destroy a base. It's simply a number made up by the game.

Yes and no. It depends on how much you spent on your army.

If you spent money on an army and:

• Win an attack on somebody too low level compared to than you,
• Lose battles completely (not even earn 1 star)
• Lose the clan war in its entirity (even though it still gives you some loot)

Then yes, you'll lose money.

However, if you created a cheap army and annihilate (win; 1 star or more) your enemy, then you'll be bound to earn more.

Your clan war win bonus is always more^ than enough to make 3 armies (presuming your clan wins the war) to take down the base you've won it from, and the lootable resources equate to about half the amount of Elixir required to make a suitable army to take down that base.

^Based on observation