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All the tools and techniques you need for clean-cut styrofoam
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Lightweight and easy to paint, styrofoam is a great material for any number of arts and crafts. Cutting styrofoam into any shape you want is easy, but you’ll need to choose the right tool for your needs. You can cut styrofoam manually with cookie cutters, knives, or box cutters. For a smoother, more finished look, use a wire cutter or an electric knife. Whether you’re making custom pieces for your cosplay outfit, unique decorations for your holiday tree, or prop elements for a theatre production, you’ll be cutting styrofoam into the shapes you need in no time!
Easy Ways to Cut Styrofoam
- Use a sharp blade like an X-acto knife to make straight cuts.
- Or, use an electric knife or foam cutting saw for more intricate lines.
- Use a sharp blade, a hot wire cutter, or an electric knife to cut styrofoam balls in half.
Steps
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Use a blade for straight cuts. Bladed implements like knives, box cutters, precision blades (like X-acto knives) or hacksaws are great for cutting through styrofoam, especially if you don’t need to make any curved cuts. For a smoother cut, run the blade along an old candle before cutting your styrofoam.
- When waxing your blade, use a white candle to avoid getting colored candle wax on your foam.
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Use dental floss for cutting through styrofoam sheets. Dental floss is great for cutting straight lines through sheets of styrofoam. Lay the styrofoam down with the floss underneath it. Line the floss up along the line you want to cut through the styrofoam, then place one hand on the styrofoam sheet to. To slice the styrofoam, pull the end of the floss furthest from you towards you.Advertisement
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Use cookie cutters to make unique shapes. If you have a relatively thin piece of styrofoam (no more than two inches or five centimeters thick), you could use a cookie cutter to cut through styrofoam. Just press the thin edge of the cookie cutter into the styrofoam until it punches through to the other side. The styrofoam piece that results will be in the shape of the cookie cutter.
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4Try cutting it underwater. If you don't want to make a mess, you could try cutting styrofoam underwater; that is, submerging a piece of it in a tub or bucket filled with water, and cutting the styrofoam underwater with a knife. This prevents the small crumbs that come off from flying all over the place, enabling you to make a faster, and hence smoother, cut. Remember to strain the water before pouring it out. The cut styrofoam block can easily be patted dry afterwards, as styrofoam does not absorb water.
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Use an electric knife to cut thicker pieces of styrofoam. If you’re cutting through several pieces of styrofoam at once, or through a single piece that is several inches (several centimeters) thick, an electric knife is your best bet. They’re best for making straight cuts, but they could also help you make a gently curving cut.
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Use a foam cutting saw to cut through larger pieces. Foam cutting saws are the best option for cutting through large bricks of styrofoam like those used to package televisions and other large appliances. However, they’re also the most expensive option, and tend to range from about $150 to $400 USD. [1] X Research source
- Generally, you can just turn the saw on and press the piece of styrofoam you wish to cut into the blade, keeping your hands clear of it. Consult manufacturer directions for the particular type of saw you’re using.
- When using a power saw to cut styrofoam, wear a dust mask and safety goggles. Power saws can create a "foam dust" that is similar to sawdust, but can irritate the lungs if inhaled.
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Utilize a hot wire cutter for smooth cuts. Hot wire cutters melt through the foam with a heated wire, creating a smooth edge. They are especially effective for creating rounded edges or shapes out of styrofoam. [2] X Research source
- Apply slow, consistent pressure with the hot wire cutter along the desired cutting line. Moving too fast through the foam will cause the wire to snap.
- Use extreme caution when operating a hot wire cutter because the wires are extremely hot and can cause severe burns.
- Hot wire cutters are great because they leave behind the fewest styrofoam crumbs and produce the smoothest cuts.
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Follow the directions for the craft you’re making. Sometimes you might make curved cuts first when cutting styrofoam, while other times you might make straight cuts. Either is acceptable as long as you’re following the directions for your project. [3] X Research source
- If you’re engaging in a project of your own design and not working with directions, you can make either curved or straight cuts first. Remember, it’s your project, so there are no rules!
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Use long, sawing motions when cutting with a blade. Keep steady, even pressure on the knife throughout the cutting process to reduce the chances of breaking or crushing the foam. Long, sawing motions will also minimize the amount of foam crumbs you produce.
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Cut out indentations from the center of the styrofoam. If you want to cut a depression in styrofoam, start in the center. Draw a line around the area you want to remove, then select a tool that will allow you to remove it while achieving a depth and a degree of curvature that pleases you. [4] X Research source
- A depression with vertical sides is best removed using a knife. Just select an appropriately long knife, then cut along the line you’ve marked.
- In some cases, indentations are best achieved using a rounded sanding tool rather than a knife.
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Cut channels in the styrofoam using a bladed tool. A long, serrated knife or an electric knife is probably best for cutting channels through your styrofoam. Mark the length and depth of the channel on your styrofoam, then punch your blade through the styrofoam to the depth you marked. When the piece is loose, remove it. [5] X Research source
- You can use this technique to cut channels that run through a piece of styrofoam or along the surface of a piece of styrofoam.
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Divide round styrofoam balls by cutting them down the middle. You can cut a round styrofoam ball in half by tracing a line along its equator with a sharp pencil. Many styrofoam balls already have this line marked by the manufacturer. Use a sharp blade, a hot wire cutter, or an electric knife to bisect the ball.
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Community Q&A
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QuestionWhy do I need to wax the knife?Community AnswerThink of the wax as a lubricant, it allows the knife to go through the product faster.
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QuestionCan I smooth the surface with a fine grit sand paper?Community AnswerNot a good idea. Even a fine grit will tear the foam: think rough sand against a very smooth surface. Instead, use a spare piece of foam get rid of the burs. Just rub the foam piece gently against the cut edge.
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QuestionCan I use a kitchen knife to cut Styrofoam?Community AnswerYes, and the ones that work best are the ones with a serrated blade.
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Tips
- To protect the work surface, use a cutting board or cutting mat when cutting Styrofoam.Thanks
Tips from our Readers
The advice in this section is based on the lived experiences of wikiHow readers like you. If you have a helpful tip you’d like to share on wikiHow, please submit it in the field below.
- Cut the styrofoam outside if you can to avoid making a mess indoors! Try to work in an area shielded from wind so the pieces don't fly around all over your yard.
- If you use a hot knife, you will not get any of the styrofoam shavings everywhere.
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Things You'll Need
- Counter top or table
- Serrated kitchen knife
- White candle
- Precision knife
- Electric kitchen knife
- Craft knife
- Hot wire cutter
- Hand saw
- Power saw
- Safety goggles
- Dust mask
- Floss
- Cutting mat or cutting board
References
- ↑ https://www.core77.com/posts/17816/how-to-cut-foam-the-dumb-way-the-expensive-way-and-the-brilliantinexpensive-diy-way-17816#
- ↑ https://books.google.com/books?id=iq_cqiFdFR4C&lpg=PA24&pg=PA24#v=onepage&q&f=false
- ↑ https://www.dltk-kids.com/crafts/transportation/mstyrofoam_airplane.htm
- ↑ https://davidneat.wordpress.com/styrofoam/
- ↑ https://davidneat.wordpress.com/styrofoam/
About This Article
Article Summary
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If you want to cut styrofoam, use a knife or hacksaw to make straight cuts. As you work, make long, slow cutting motions to reduce the risk of damaging the foam. When working with thicker pieces of styrofoam, use an electric knife or purchase a foam cutting saw. To cut a sheet, place it on top of a piece of dental floss, hold the sheet down, and pull the end of the floss furthest away from you towards you. If you'd rather cut unusual shapes out of your sheet, cut the foam with a cookie cutter. For advice on how to cut depressions or channels into your styrofoam, keep reading!
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Reader Success Stories
- "I had a school project where I had to drop an egg off of the roof of the cafeteria (about 20 feet). I needed to cut a hole in a Styrofoam ball to put the egg in. It really helped, and I got a good grade." ..." more
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"I had a school project where I had to drop an egg off of the roof of the cafeteria (about 20 feet). I needed to cut a hole in a Styrofoam ball to put the egg in. It really helped, and I got a good grade."
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