Fiberglass is actually very flammable.
No. Once fiberglass is set, it cannot be altered.
I think it is arounf 9w/m2k
Sears Gamefisher 14' Tri Hull Fiberglass Boat
A sailboat whether it's single hull (one hull) or a multi-hull (more than one hull) can be made of different material. The majority of today's sailboats however are made from fiberglass. This is mainly because fiberglass is strong, can absorb shock (to a certain extent), is relatively cheap to make (compared with other materials such as wood) and is easy to make a mold out of.Some of the older sailboats are made from wood and some are also made from steel. There are both pros and cons to this as wood and steel are heavier than fiberglass and therefore take more energy (wind, fuel etc) to move the boat along.
Fiberglass.
You can learn how to repair hull holes in fiberglass boats here: http://www.boatus.com/boattech/casey/17.htm
The hull on a boat is the body of it. It is watertight so that no water leaks in and sinks the boat.
On the hull
Displacement: The weight of the water the boat displaces. Hull weight: The weight of the hull of the boat
the hull helps keep the boat stable, if there was no hull, the boat would go in different directions
A hull is the watertight body of a ship or boat. Above the hull is the superstructure and/or deckhouse, where present. The line where the hull meets the water surface is called the waterline.
The hull of a boat is the main body that rides in the water. Engines, Decks, masts and rudders are all installed in or on the hull.