Need help. Elemental damage greyed out on a weapon

[Algol]

Just finished the tutorial, aka Low Rank play, and now I really need to up my dual blades loadout for the big league. My garon hatchets which I want to upgrade to blood drinker chainblades have fire element damage in their stats, but it is greyed out and doesn't work. Now, I know you need to have either a skill for fire attack on your armor or a free elem skill [monsterhunterworld.wiki.fextralife.com] on armor or charms, and I don't have any (using garon armor set). But my madness pangas have water elemental damage and it does work without elem skills.
Am I understanding this correctly: some weapons have in-build elem damage and some weapons have it locked for you to unlock it? What should I do with my current build?

[Apothecaryᴿˣ]

Yes you’re right that some weapons have this attribute; it’s a hidden element. Fire attack won’t unlock it. If you’re using a weapon with a hidden element, u need to spec for free elem. Either run KT coil and Kirin pieces, awakening charm, or release jewels.

[Lord Regal]

Fire damage ^ skills/decos take a non-grayed out fire element and make it stronger.

Free element takes a grayed out fire element and makes it non-grayed out.

To use the element, you just need it not to be grayed out.

Edit: replace fire with whatever element you want. Just using fire since that’s the one in question here.