The key is called "Weapon store key" you can buy one from the Grand Exchange or going upstairs the Black Arm Gang and killing the smith (or whatever it is up there).
Presuming you're doing the quest "Shield of Arrav".
it should be right next to the actual hideout.
it is in the southern area of varrak (spelt right?) if you need more help add me i am called ledgabomb and always happy to help!
in the drain in varrock place us water in the drainage pipe and then go to the swears to wear the pipe ends
Godswords.
advice: get a weapon
A Weapon
There is no weapon stash in Runescape. If you need a sword or armor, you can either buy it at the Grand Exchange located at Varrok, or you can make your own.
There's weapon stores in almost every town around Runescape, look for a Sword, Bow, or battleaxe icon on your mini-map.
nothing
If you have a weapon in your inventory, click on it to wield it. This will un-wield any other weapon you have in your weapon slot.
Any weapon that has a great crush bonus:BattleaxesMacesMaulsWarhammers
all you need to do to get poison off of a weapon is use a cleaning cloth.
Dragon claws
Gravite shortbow.