Introduction: Giant Cereal Box/Secret Shelf

About: I am an 18-year-old student in 12th grade, I enjoy baking, running, programming, 3-D design, photography, and nature!

This instructable will show you how to make a giant cereal box that has a hidden shelf inside. But why would anybody want this? Well, why wouldn't you want this, it's a super fun thing that will make any room look super cool. It looks like a large pop art installment, so nobody will touch it, thus you can keep things hidden inside of it.


To build a giant cereal box, you will need the following materials:

- one 4'x8' piece of sanded plywood, 1/2" thick

- one eight-foot 1"x2", you'll only need about 60 inches of it

- 20-30 very small nails, around one inch long

- 10 longer nails

- wood filler or wood caulking

- primer

- various colored acrylic paint

- masking tape

You will also need the following tools:

- table saw or circular saw with a guide

- miter saw (you could also just use a circular saw for this)

- hammer

- clamps

- tape measure

- straight edge

- precision and or speed square

- pencil

- paintbrush

- paint roller and tray

- projector(optional but helpful if art isn't your strong suit)

Step 1: Cut the Boards

To build the box, you will need to cut one sheet of 1/2inch plywood to the following sizes:

- one 30"x48"

- two 6"x48"

- five 6"x29"

You will also need ten 6" sections of 1"x2"

At any point, if you are confused about the build process, I have attached a 3D STL file and a SketchUp file.

Step 2: Assemble the Shelves

The first step to making the box is to attach the sections of 1"x2" to the 29" boards. To do this, set two of the 1"x2" sections on their narrow sides so they are parallel and they are as far apart as the length of one of the 29" boards. Place one of the 29" boards on top to like in the second picture. Attach the 1"x2" pieces to the ends using nails, make sure that the sides are flush. Once attached they should look like the third picture when you flip the board over. Attach the 1"x2" boards to the ends of all five of the 29" boards in the same manner.

Step 3: Assemble the Plywood Frame

Now you will need the two 6"x48" boards as well as two of the shelves from the last step. Now arrange them like picture two where the longboards are on the outside and the shorter ones are on the top and bottom. The corners should be flush and the 1"x2" boards should both be on the inside of the rectangle. Use clamps to hold the boards together, and use nails to attach the corners together. When you have done all the corners, it should look like the last picture, don't worry if it is a little warped, we'll fix that in the next step.

Step 4: Attach the Main Board

Now we are going to attach the main board, this will act as the front of the cereal box and it will hold the shelf together. Place the 30"x48" board on top of the rectangle from the last step. Start by lining up two of the corners and adding longer nails about 7/8 inch from either side. Once you have done two corners, line up the other ones, and add long nails to those. Next, you will add shorter nails all along the perimeter. Start at one corner and add one nail about every 5 inches, the nails should be inserted 1/4" from the edge. As you go around the perimeter, you will have to make sure that the sideboards stay flush with the mainboard. If the side boards are bowing out from the mainboard, then push them so they are flush. If they are bowing inward, prop the whole box up and reach under the sideboard to pull it out so that it is flush. Once you have nailed nails the whole way around, you would be able to stand the box up.

Step 5: Add the Shelves

First, you must measure out where the shelves will be. Start by measuring from the top of the box down one of the sides on the back of the box, make a mark at 10 inches, 20 inches and 30 inches. Repeat this on the other side. Set the box on its side and place the shelves in it so the surfaces line up with the marks on both sides. Nail in one nail on either side, through the side of the box into the 1"x2". Use a speed square to check that the shelf is perpendicular to the wall of the box. Then add one or two more nails to both of the sides. Do this for all three shelves so that one is at the 10-inch mark, one at the 20-inch mark, and one at the 30-inch mark.

Now flip the box over and add larger screws to the back, you want them to go into the 1"x2" shelf boards. To do this, measure down from the top to 11 inches, 21 inches and 31 inches on both sides of the box, make marks at those measurements. At those marks, nail in screws about 7/8 of an inch from the side of the board. After doing the first one it is a good idea to flip it over and check that the nail isn't showing if it is showing remove it and check you are measuring correctly from the top of the box.

Step 6: Sand and Fill Holes

Now that you are finished assembling the box, it is time to prepare it for painting. First, you must sand the entire thing to get rid of any splinters or rough spots on the wood. Start with low grit sandpaper, below 100, and remove any splinters. Next move to something a little higher, 100-200, and begin to smooth the surface and edges. Finally move to something high, at least 220, and make everything as smooth as you would like. If you are using high-quality plywood, you may want to just start with a high grit, or you may not want to sand at all.

Next, you will need to will any remaining holes or cracks. To do this, get some wood filler, or silicone wood caulk as well as a paint scraper or taping knife. Apply the wood filler to an area and smooth it out using a slightly damp scraper until it is smooth. Do this over the entire surface until no large cracks or holes remain. It is up to you how far you take this step, you can just fill the large holes, you can do the whole thing, or you can skip this altogether if you are ok with the texture of the wood showing. If you are using high-quality plywood you may not need to do anything to get it smooth. Once you have completed, allow it to dry as directed by the filler or caulk that you used.

Step 7: Prime

Next, you will want to apply a coat or two of primer. I'm just using an all-purpose interior/exterior primer, but what primer you should use is dependant on where you want to keep your box. If you plan on having the box outside at all, you should use an exterior primer. Use a paint roller to apply the primer to the surface and sides of the box. Allow it to dry and then apply another coat if you can still seed the wood color. Continue to add coats until the wood is no longer visible. Next, if you desire, prime the shelves until the wood no longer shows through. Allow the primer to dry thoroughly before moving to the next step.

Step 8: Sketch Guide Lines

Now that the box has been primer, it is time to add the foundation for the design. If you are using the design I used, you will want to follow this step exactly, otherwise, for this step, you will just want to sketch out where the different background colors will go.

To create my design you will need a precision square, a pencil, and a tape measure. Start by making the title box, use the guide images to measure out the position and size of the rectangle. This box should be 3 inches down and 4.5 inches from the sidewalls, it should be 21 inches wide and 19 inches tall. Next, make the small partially rounded rectangle. This one should be 24 inches from the top and it should protrude 9 inches out from the side and it should be 6 inches tall. Finally, make a box for where the Maxi Wheats will go, this box is just a general guideline of where the wheat will go so it's ok if it's not perfect. It should be 4.5 inches from the bottom, 18 inches tall and it will span 28 inches from the left side.

Once the boxes are complete, use a round object about 5 inches in diameter to create round on the corners of the top rectangle and the small one on the side. As you can see I forgot to do this until after I painted my first coat, but I recommend doing it now. Your sketch is complete when your box matches the last two images.

Step 9: Paint Base Color

Now you will create the main background color. When I did this, I created a gradient going from red to orange, however, if that is confusing, just pick one color and make in all that color. Start at the top with orange, paint everywhere but inside the boxes, those will be filled in later. As you move down, if you would like a gradient, slowly add small amounts of red to the orange paint, at about halfway, you should be using 50% orange and 50% red and by the bottom, you should be using just red. Pay attention to what amount of each color you used, as you will need to add more red and orange paint later. When you are done you should have three boxes of white and the rest red. Now paint the sides following the same gradient(if you used one) as before, don't forget to leave the nutrition box blank. If at any point you cross over the lines, don't panic, we will be adding borders to the boxes so the paint seems will be covered up.

In this step, I've also included the JPEGs for the front and side. You should download these and refer back to them during the entire painting process.

Step 10: Add More Colors

Now you will want to fill in the top boxes. The first one is the large rounded rectangle where the title will go. For this, I mixed yellow white and a tiny bit of orange, but you could just use a standard yellow or peach color if you don't want to worry about mixing paint. Fill in the entire box up to the edge, fo worry if you go over the lines a little bit, there will be a one-inch border here. Next fill in the smaller rounded box, paint this in using a light green color. After doing these your box should match the final picture, you may need to add multiple coats if you can see white underneath.

Step 11: Paint the Title

Now we get into the more difficult painting! Unless you are a very very skilled artist, you will want to use a projector for this step. Set up a projector with a laptop connected to it in a somewhat dark room. Adjust the high so it is pointing right at the yellow box. Open the included JPEG called "Frosted Maxi Wheats Box Design" in a photo viewer. Scale the image so it projects into the box will at least 1/2 inch of space all around. Once the projection looks good, use a pencil to trace the outlines of the different colors, you should have an outline for the light blue, dark blue and for the letters.

Once you have traced the entire thing, turn the projector off and make sure you aren't missing anything form the design. Now use a light blue to fill in the area that is light blue in the JPEG, for this, it is very important that the outside stays within the line, however, you can cross over the inner line as the dark blue will cover it. Once it appears like the fourth picture, allow it to dry and you can begin the next color. Now you will use dark blue to paint between the light blue and the text, none of this will get covered so paint inside the lines to the best of your ability. Once all the dark blue area has been filled in and has dried, you can fill in the text with white. Be very careful to not cross over the lines. The white may take multiple coats, you are finished when it looks like the last picture and you can't see any yellow underneath.

Step 12: Add Borders

Now we are going to add borders around the yellow and green boxes, the borders will cover the seams and make the box much more polished. To make the border, you must first make marks for where you should put the tape. First, go along the border and make marks 1/2 inch from the line along the inside and all along the outside. Make sure to sketch in the curves. Add pieces of masking tape parallel to the lines alongside the marks, stop at the covers, those you will have to freehand. Paint int between the tape all the way around, at the curves, freehand a curved line 1 inch in thickness.

Step 13: Paint the Maxi Wheats and the Side Label

For this step, I highly recommend using a projector. First, you want to set up the projector so that the Maxi Wheats are centered in the blank box and so that the text in the green box is inside the green box. Once you have your projection in the right place, trace the Maxi Wheats and the text label. Use the orange and red paint to paint around the Maxi Wheat tracing, make sure to match the surrounding colors and blend the paint to hide the seems. Once that paint has dried, it is a good time to erase the outermost pencil lines.

Next, cover or turn off the projector(try not to move it at all) and paint in the text for the label with white paint; allow it to dry.

To paint the Maxi Wheats you will need the following colors: dark brown, light brown, peach, light grey, and white. To paint them, you can either project them again or paint them completely free hand. Whatever way you chose, I found the best luck by starting with the dark brown first, filling it in anywhere where you see dark brown in your reference image or projection. Allow those to dry, next layer on light brown, and after that finish with streaks of peach. Once you have finished with the browns, you can begin to add the frost. Although your white primer may still be showing through, by adding more white and light gray, you can create the frosted texture. Anywhere where you see shadows in the white frosting and in the milk, add light grey to mimic those shadows.

Step 14: More Borders

Now we are going to add two more borders. The first one is going to be for the green label. To make this label, you are going to tape it off just like how we taped the yellow one. First, tape strips of masking tape 1/2 inch from the three lines, starting at the curves and ending at the end of the box. For the inside strips, they must end before the curve. In the middle of the curve, make a mark 1/2 inch on either side of the line. Sketch a curve in pencil that lines up with the pieces of masking tape as it appears in the first picture. Use a brush to fill in the lines, allow the paint to dry, and add more coats if you can still see the colors underneath. Once you have completed the first three lines, we're going to add a line on the corner. Add masking tape 1/2 inch on both sides of the corner from the top to the bottom of the green label border. Paint in the strip.

Next, we're going to make the nutrition label a perfect rectangle. To do this, tape pieces of masking tape around the edges of the rectangle. Paint in the rectangle with white paint. Allow it to dry and then remove the tape.

Step 15: Add the Weight Label and Nutritional Info

The last step is just adding text to the bottom of the box and the nutrition label. If you would like, you can make these fake writing which will save time but still give the box a cool look. Otherwise, I recommend projecting the designs I've created and then tracing the letters. As you can see, I used real text for the first have of my nutrition label and I created fake text for the smaller text, what you want to do is up to you. Either way, I recommend using masking tape to create a thin black box in the nutrition label about a 1/4" from the edge of the box. I also think it is a good idea to use masking tape to create the lines within the box so that they are straight and even.

Step 16: You're Done!

Your Cereal Box is done! You can now move it to wherever you want to keep it, and you can fill up the shelves with all you're secret and valuable belongings.

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