There has been a couple of threads about why cakes should be braced:
[Edit] I merged a thread about "Cakes - Stake Tape or Boards?" into this one and I changed the title to "Braces & Barricades & Boards & Tape"
From these threads we learned a simple rule of ABC:
Always Brace Cakes
Always Barricade Cakes
Instead of another thread about why to brace cakes, this thread will be about how to brace cakes. This thread will be about techniques and items you can use to brace or barricade your cakes. I hope other members will suggest and show pictures of how they brace their cakes.
Click for full size: http://www.pyrouniverse.com/gallery2...arricade01.jpg
My favorite technique is the barricade box. You will note there are two black wooden boxes (about 2'x2'x1'). These two boxes have a wooden floor as well. This is where I put bigger, harder hitting cakes. Between these two boxes I clamp two wooden boards (8'-10' long) that are clamped to the boxes with heavy duty clamps. This forms a large box about, 12' long by 2' wide and 1' high. The smaller cakes are placed in between the wooden boards. There are even small slits in the black boxes to make it easier to run ematch wire.
Interesting enough, it was at this show, in the above picture that the barricade box proved itself. This was the only time I had trouble with a cake. During the show, while a cake was about 3/4 of the way done, it blew apart. Some of the tubes were laying at odd angles when they fired. All those shots stayed in the barricade box, instead of firing in every direction or angle. Instead of having a safety issue, the box turned into an amazing mine display as the shells broke inside the box. No other cake was damaged or knocked over by malfunctioning one. So the barricade box "worked as intended".
Click here for full size:http://www.pyrouniverse.com/gallery2...arricade02.jpg
Here is another view of the barricade box at another venue. If you look between the two boards, you will note that there are sets of cakes duct taped together. This is another way to make cakes more secure and stable. The cakes are braced up against each other.
Click for full size: http://www.pyrouniverse.com/gallery2...arricade03.jpg
Sometimes the ground at a site is rather soft. So you can place one of the side boards on the ground and place the cakes on it. The other side board acts as a barricade between the cakes and the spectators. Obviously, this is only effective if the spectators are in one direction, instead of several directions.
Click for full size: http://www.pyrouniverse.com/gallery2...arricade04.jpg
Here is the side the audience sees.
Click for full size: http://www.pyrouniverse.com/gallery2...arricade05.JPG
Here are some examples of stakes I use. The ones on the left are wooden 1"x2" stakes. They are either 12 or 16 inches long. You just take a 8' 1x2 and cut it into either 6 or 8 pieces. You then take a saw or a hatchet and make the end pointed. The other stakes are 1/8" steel rods. You bend them into "crochet hoops" of whatever size you wish (long and narrow, or wide and shorter) and works best for the cake you are trying to stake.
Click for full size: http://www.pyrouniverse.com/gallery2...arricade06.JPG
Here is an example of a staked cake. There are two wooden stakes on either side of the cake. There is gaff tape (duct tape, strapping tape, fiber tape, etc) wrapped around the cake and the stakes. The stakes are on the sides that are towards and away from the audience (the stronger sides). If cake should malfunction, the sides 90 degrees to the audience are weaker. This should encourage any tubes or fireworks to go 90 degrees to the audience instead of at them, if the tape should fail. Since the cake is wedged between the stakes, this will also keep the cake from moving about.
Click for full size:http://www.pyrouniverse.com/gallery2...arricade07.JPG
Here are examples of staking cakes using the wire or "crochet hoop" stakes. Like the wooden stakes the wire stakes are placed on either side of the cakes (towards and away from the audience. The wire stakes can be rebent to better fit the cake and the hardness or softness of the soil (softer soil needs longer stakes). The cake is wedged tightly between the stakes and gaff tape (duct, strapping, fiber, etc) is wrapped around the stakes and cake.
You will note that the back cake has its own wooden base. The wire stakes work well for staking down the corners of the wooden base to the ground. If desired, tape can be wrapped around the body of the cake.