How to Make a DIY Styrofoam Puncher Used in SNAP Grow Box Construction

The SNAP Hydroponics system utilizes used styroboxes (EPS foam boxes) to contain the nutrient solution and hold the seedling plugs in place. One of the steps in making grow boxes is to add the holes on the upper half of the styrobox where the seedling plugs would fit. One of the ways to accomplish this is with the use of a do-it-yourself (DIY) tool made of empty tin cans—styrofoam puncher a.k.a. pambutas ng styro.

Materials

Below are the materials required to make this tool:

Empty Tin Can

An empty tin can with a 3-inch diameter. These are pretty common since tin cans follows standard sizes. To verify if the holes made with a tin can will fit your styro cup, fit them to the can itself as demonstrated in the picture below.

I recommend using cans with ribbing along the side. The ribbing adds lateral stiffness of the can and allows it to hold its circular structure even when the lip of the cut has been cut off to sharpen the cutting edge.

Bamboo Sticks

A pair of bamboo sticks or other materials strong enough to serve as handles for the tool. For bamboo sticks I recommend making a pair of them by dividing a single half inch thick bamboo stick into a quarter inch pair by splitting the stick along the grain. It should be long enough to run along the diameter of the tin can and have around 3 inches protruding from the sides of the can. Make sure to smooth out the edges as well as the cut ends of the bamboo sticks to remove splinters and sharp edges.

Rubber Band

Rubber band or other materials that can lash the pair of sticks together. A sturdy length of string or fishing line works too.

Equipment

You’ll need a pair of tin snips to cut away the lip of the can and make a sharper cutting edge.

You’ll also need a piece of bamboo stick with a pointed end that you’ll use to add a hole on the can for the handles to go through. It should be around 3-5 inches long with the same cross section as the bamboo sticks you’ll be using as a handle.

You’ll also need a knife of a bolo to work with the bamboo and the tin can. You’ll also need a can opener to remove fully open one end of the can.

Procedure

Start by using a can opener to fully remove one end of the can.

Then using a knife or bolo add “T” shaped cut on one side of the can near the closed end. This “T” shaped cut will make sure that the hole will be centered and even when you enlarge it using your pointed bamboo implement.

Using our bamboo tool, enlarge the “T” shaped cut to make a larger hole. You can use any appropriate tool to hammer it through the can.

The “T” shaped cut makes sure that the hole enlarges evenly and stays centered as shown in the picture below. Repeat this process on the opposite side of the can.

Push one of the bamboo sticks through the holes you made. Make sure it is centered so that the length of the handles are even. Put the other half on top and so that the lid of the can is sandwiched between the pieces of bamboo. Then lash them together tightly with a rubber band or string.

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Lastly, if preferred, the cutting edge of the tool can be sharpened by cutting off the lip of the open end of the can. Although this step can be performed before any other steps, we recommend doing this last because the cut edge is indeed sharp. It is sharp enough to cut through skin. The other activities will have a risk of giving you a cut if they are performed with the lip of the can removed exposing a sharp edge.

Questions

Can I use a single piece of bamboo going through one of the hole, inside the cut, though the hole on the other side?

Using a single piece of bamboo saves time and effort. However, the rocking motion this tool will experience as you use it to make holes on your styrobox will ruin it pretty fast. The handles will exert pressure on the holes. The sides of the can is very thin and soft. The pressure exerted by the bamboo stick will be enough to enlarge it and pretty soon it will be too large for the tool be useful. Sandwiching the lid with two pieces of bamboo lashed together will transfer the force to the lid which will be able to handle the forces.

Can you show me how to cut the lip of the can with a tin snip?

I’ll upload of video soon.

That’s it. If you have any questions, please feel free to leave a comment below.