Difference between revisions of "Fiberglass Form Making"

Latest revision as of 17:26, 20 November 2016

Fiberglass form making

Fiberglass can be formed over many different surfaces and materials. When Fiberglass resin cures, it puts off a substantial amount of heat, so the worm material must be resistant to the heat.

The most common form material used in many aircraft is foam. There are many types of foams and each foam has its own positive and negative attributes.

For the topic of homebuilders, we will discuss your common foams available at Home Depot or Lowes. Remember these are Forms and do not need to be aircraft grade pending your final part made of fiberglass is.

Closed Cell vs Open Cell Foam

Imagine if you filled a box with golfballs. CLOSED cell foam is where foam fills the place of the golf balls. OPEN cell foams are where foam would fill the voids between the golf balls. Each has a unique use. Note, most OPEN cell foams are toxic to melt, so you should not hotwire these, while Blue and Pink foam generally are safe to hotwire.

Blue, Pink, Yellow, or Green? Blue or Pink Foam - These are typically PolyStyrene foams. These are Extruded and available in 1/2" to 2" thicknesses locally. This foam is a CLOSED CELL foam and can be safely hotwired.

Yellow or Green Foam - These are typically Open cell foams that are toxic to hotwire. Green foam (Available in small quantity at craft stores) is easier to sand, but all hotwireing should be avoided. This foam gives off cyanide gases when melted.

So how do I make a form?

Blue and Pink foam can be hotwired, are redily available at all home improvement stores, and sands smooth. A hotwire can be made easily from an old 2x4, some steel tubing, safety wire, and a battery charger (All things most of us building an airplane have laying around in our hangers and workshops)