Thread: Differences Between Bondo and Fiberglass?

im not going to explain in great detail but i will explain the basics.
fiberglass is a type of fabric made from woven glass fibers and plastic reinforced by glass fibers. it is the material that defines a shape and makes it hard.
body filler or bondo is a polyester material used to smooth out bodywork or used to repair dents or dings in metal.

you first lay out fiberglass to make a general shape of what you want. fiberglass makes it sturdy and hard. then you put bondo over the fiberglass to smooth everything out.

it just depends on what you are doing (project wise) but i prefer to work with body filler more because its the layer that makes everything looks smooth and perfect and is pretty easy to use, after you get used to it. fiberglass is sorta hard to work with since its stringy and sticky.

hope that helps

I think he means the fibreglass stuff like bondo in a tube.

I was avoiding it cos i couldnt be arsed and it doesnt take much research but i hate it when threads are left with incomplete/incorrect answers.....

The fibreglass that comes in a tube with separate hardener like bondo is an epoxy style resin (like you use for fibreglass layup as Projectwidow describes) with whiskers of fibreglass in to reinforce the epoxy which would otherwise be very brittle. The idea is exactly the same as for the lay up fibrelgass mat and resin but this is good for making shapes and blocks that you can file down.

The fibreglass stuff is considered structural unlike bondo which should only be used in thin layers to impove the surface finish and will crack if used too thick or for structual purposes.

fiberglass is a reinforcement, bondo is a filler.