Homemade Silly String

Calculate the amount of Silly String needed. The compound uses 15 percent polyisobutyl methacrylate (acrylic resin) which is also found in Lucite and Plexiglas. This is combined with approximately 4 percent sorbitan trioleate (surfactant) and 70 percent dichlorodifluoromethane (propellant). The remaining 11 percent uses flame retardant and silicone liquid.

Add the acrylic resin to the aerosol can. The ratio needs to be correct, 15 percent, to guarantee the proper consistency. Too much resin will result in a thick substance about the consistency of caulking and too little will keep the compound from solidifying properly when sprayed.

Add the surfactant to the aerosol can and the acrylic resin. Keep the ratio to between 3 and 5 percent to guarantee results. Too much surfactant will make the resulting compound very sticky and may cause problems when trying to remove it from sprayed surfaces. Too little, and the Silly String will not adhere properly.

Mix in the propellant. At least 70 percent of the final compound is propellant. This forces the ingredients out of the aerosol can and gives the Silly String its patented delivery method.

Use the silicone liquid to further balance out the adhesiveness of the compound and the flame retardant to make the compound slightly safer. Mix in the plasticizer to make the strands stronger. The exact ratios will depend on the flame retardant used and the relative stickiness of the original compound. Use more silicone liquid to make the compound easier to remove from surfaces such as carpets. Avoid using too much plasticizer or the compound will solidify before being sprayed.

Seal the aerosol can and test the Silly String compound around the house. Spray the compound on various surfaces to measure the desired stickiness, strength, and other attributes.