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Discussion Starter · #1 · (Edited)
Note: This is a repost of an old tutorial whose links to pictures were broken with the software update at HF.

Steel I-beams are critical set pieces for an industrial/factory room in your haunt. Luckily, they are simple to make using foam. Plus, they are just fun to have around the house. Heh

Here's a video of them scattered around the basement:

Items Needed: (to make 6)
One sheet of 2" pink or blue styrofoam
Partial sheet of 1/2" pink or blue styrofoam
Scrap section of 3/4" pink or blue styrofoam
3/4" diameter wood dolly
3 or more tubes of foamboard adhesive
Gray latex Drylok
Monster mud colors (see griming tutorial)

Tools Needed:
Band saw (or table saw)
Jig for band saw (used a furring strip)
2 clamps (to hold jig on workbench)
Caulk gun
Ruler with metric readings
2" paint brush
Small paint roller

Cut Beams (not pictured): Divide your sheet of 2" styrofoam into six planks lengthwise. You should end up with six 8' long 8" wide planks. A table saw would be the easiest tool to cut them apart but I used a band saw (all I had).

Cut Flanges: You will be cutting the 1/2" thick foam into 1/2" strips 8' long to make the small edges of the I-beams. A table saw would, again, be the best tool. If you don't have a table saw then you'll have to make a jig for your band saw to cut the small edges of the steel I-beams. If you have neither tool then perhaps you can cut the strips using some other foam cutter. Just bear in mind that the strips look and glue on better when they are cut in nice straight lines. A jig or table saw makes it easy to stay on target and make the strips fast.

Set-up your jig so the band saw (or table saw) will cut 1/2" wide pieces. You will cut the whole length of the foamboard (8'). For six I-beams you will need 24. If you only had a 4' long piece of foamboard left like I did, then you'd need 48.

Note: In the picture you will see that the pieces cut is smaller than 1/2" wide. This was for another project but was the only picture of the jig I had. Your pieces will be wider.

Glue Flanges: Using a thin bead of foamboard adhesive, glue the cut side of the flanges to each edge and on both sides of the I-beam. If the glue squishes out the sides, wipe it up with a paper towel.

I like the opposite cut side showing because it has a rougher surface than the smooth side. Seems more like metal to me but it's your preference.
Note: I only had 4' long flanges available, so I had to join them up.

Make Hex Nuts and Bolts: Above is an animation to show you how to mark your scrap piece of 3/4" foam to give you the shape of hex nuts. This, by the way, took hours to figure out. Math is hard!

Note: To make the needed 144 hex nuts you will need a slightly bigger scrap of foam then shown here. This scrap only made 110 hex nuts.

Step one: Draw horizontal lines 1 1/2" apart from each other on the scrap 3/4" thick foam.

Step two: Use the metric markings on the ruler to mark dots every 2.2cm. So it would be marked at the 2.2, 4.4, 6.6, 8.8, 11, 13.2, 15.4, 17.6, 19.8, 22, 24.2, 26.4, 28.6 and so forth.

Step three: Draw a diagonal line to its corresponding mark. Skip a dot and draw the next diagonal line. You will start to see the hex design on the nut.

Step four: Draw opposite diagonal lines to complete the markings.

Final picture: I blacked-out the parts that you will cut off so you can see the hex pattern more clearly. You don't need to do this step. I just did it as a better visual for this tutorial.

Cut-out Hex Nuts: Finally, the band saw is the best tool for this. Cut-out all hex nuts.

To finish, cut the hex nuts in half to double the number of hex nuts you have. You will need 144 of them total. They will be about 3/8" thick. I used a clamp-like jig to keep my fingers safe while doing this.

Cut Bolts: Band saw the 3/4" wood dolly to make 144 'coins' (about the thickness of a nickel). These will be the bolts in the center of the hex nut.

Another way: Dave Lowe has a neat way to make these hex nuts and bolts. You may want to consider this as an alternative: http://davelowe.blogspot.com/2009/08/halloween-09-molding-and-casting-cheap.html

Glue nuts and bolts: Use foamboard adhesive to glue on hex nuts then the bolts. Glue a grouping of four at the top, bottom and center. Repeat for the other side.

Drylok: Paint all I-beams with two coats of gray Drylok.

Grime: Grime up the I-Beams using the 'Grime up Props' tutorial found here but use rust as the base color:

That's it! Now, get your kids and show them how strong you are by lifting one up with your pinkie

Another shot of them in the haunt. You can use these as barriers or walkways.

Thanks for checking out another one of my tutorials

14,440 Posts
The Hex nuts and bolts look great.

I bought some plastic rivets to use for some of my foamboard projects and hope to paint them in place. Not the same but frequently seen on girders and iron work.

8,388 Posts
Discussion Starter · #3 ·
The Hex nuts and bolts look great.

I bought some plastic rivets to use for some of my foamboard projects and hope to paint them in place. Not the same but frequently seen on girders and iron work.
Great idea to use the rivets. The hex bolts are cool and all but took some work and time. It's always preferable to buy than make. Time is precious - especially at this time of year.
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