Monica: IDK about fiberglass. -- Some tubs are made of fiberglass+resin, or plastic. These can burn or melt. I would not want to breathe those fumes.
I don’t think you can. The fires heat will melt the fibreglass. Sorry!
Fiberglass doesn't seem like the best choice for a firepit.
Unfortunately a hot tub is not a good material to use for a fire pit. There are loads of other great ways to create one here on Hometalk.
Hi Monica, if you are looking to repurpose the hot tub I have found a few ideas for you, fiberglass is not a good choice for a fire pit, it will melt and create some really awful gases that are dangerous for anyone or anything to breath in. Here are some other ideas for you though. Hope they help you out
Don't use it around fire.
Fiberglass might be more conducive to a koi pond than a firepit that would have extreme temperatures.
Burning fiberglass gives off not only nauseous fumes but they are also toxic. This is, in part, because fiberglass contains formaldehyde.
Here's a bunch of reason to not burn fiberglass:
A firepit and fiberglass is not a good mix! Fiberglass will burn and disintegraste, not to mention the noxious gases you'll create. Best to create a firepit out of stones, concrete, metal.
Sorry to put a dampener on your idea, BUT Fibreglass is a HEALTH RISK TO BURN OR CUT UP! Please don't do it! You could end up with an uncontrolable FIRE!!!!!! and if the flames don't get you the SMOKE sure will!!!!!!!!! Be safe my friend......Don't do it!