How To Create A Permanent Seal In A Plastic Bag

Permanently sealing a plastic bag is a good way to make your own treat bags, or to reseal a package once you've removed some of its contents. Although a vacuum sealer is an easy way to seal plastic, it's not the only method. A flat iron for hair or even a crafting torch and a knife provide enough heat to get the job done properly. Some plastics work better than others; the type of plastic used for food storage bags is a good place to start.

A flat iron, also known as a hair straightener, offers enough heat to seal plastic bags with ease. Start with a low to medium heat setting, as all flat irons heat differently, and it's a good idea to use as little heat as necessary to create a permanent seal in the plastic. Fold a piece of foil or thick paper over the top and bottom of the area you'd like to seal on the plastic bag, as this keeps the iron from actually touching the plastic. Although it's possible to seal the bag without covering the plates of the flat iron, this helps prevent melted plastic on the iron if the iron gets too hot.

Lift the plastic bag end up, complete with paper or foil, then run it between the plates of the flat iron to heat-seal the bag, moving the iron so it doesn't melt the plastic, much like you move a clothing iron while ironing to avoid burning fabric. The foil or paper should be touching the flat iron as the flat iron makes a straight pass over it. If it's awkward to hold everything at once, enlist a friend to hold the plastic bag while they keep the paper or foil in place and you manipulate the flat iron.

A butane torch designed for crafting emits a small, precise flame perfect for warming up a knife blade to serve as the bag sealer. A torch that stands on its own is ideal, as keeping the flame in one spot is a good idea for safety purposes. Any metal knife with a non-serrated blade will suffice; one with an insulated handle helps ensure the heat won't transfer through to your hands. The blade should be at least as long as the sealed edge you're trying to create in the plastic, as this ensures a clean, straight seal.

Light the torch as indicated by the manufacturer, as the method may vary depending upon the torch type. Carefully move the length of the knife blade through the flame so the entire blade travels through the flame in about five seconds. Touch the blade to the plastic where you'd like to create a seal, rocking the knife from tip to handle if the blade doesn't touch all at once. Lift the blade away and check for a seal on the plastic. If the plastic didn't seal, heat the blade for slightly longer and try again.

Only adults confident with using a butane torch safely should use the torch-and-knife method to seal plastic bags. Keep young children and pets away while using the torch.