I was trying to build a surfboard core from a cardboard

The idea of filling each space in the lattice with lightweight clay had finally made this seem possible.

I immediately began pressing the clay I had purchased into each individual opening.

Even though the experimental core was quite small, the work required far more patience than I had expected.

Eventually, I finished filling every space. I stood the core in a well-ventilated place and left it there to dry thoroughly.

Several days later, after making sure that it was completely dry, I began cutting it with a utility knife designed for cardboard.

Working slowly and carefully, I managed to cut out something that resembled the outline of a surfboard.

But then I discovered another problem.

Whenever I cut diagonally across the lattice, pieces of the clay would break loose and fall out.

I would glue each fallen piece back into place and then continue cutting.

Again and again, I repeated the same process.

After dealing with one small problem after another, I finally finished cutting the entire outline. For the first time, I held a prototype shaped like a surfboard in my hands.

The real challenge, however, was only beginning.

I now had to transform this flat outline into the three-dimensional form of a surfboard.

I needed to create smooth curves running lengthwise, across the width, and diagonally over the entire surface.

"How am I supposed to do that?"

"What kind of tool should I use, and how should I use it?"

This was a completely unknown field to me.

I searched through books at the library and looked for information on the internet.

No matter how much I searched, however, I could not find a direct answer to my question.

Perhaps that was only natural.

I might have been the only person in the world attempting to do such a thing.

With that thought in mind, I decided to take a chance and use a disc grinder that I had at home.

Looking back, it was a dangerous experiment. I did not yet fully understand either the nature of the material or the power of the tool.

I plugged the grinder into an electrical outlet and switched it on.

"All right. Let's do this."

The grinding wheel began spinning with a loud, low roar. I moved it toward the surfboard core.

The moment it touched the surface, there was a sudden explosive sound.

Pieces of material flew in every direction.

A cloud of white dust spread through the workspace like smoke.

For a moment, I had no idea what had happened.

I forced myself to remain calm and first checked my body for injuries.

Fortunately, I was unharmed.

Only then did I look around.

The small surfboard prototype I had worked so hard to create had been destroyed around its outer edge.

The lightweight clay that had taken so much time and effort to pack into the lattice had been blown away. Parts of the cardboard framework had also been torn apart.

For a while, I could only stand there, staring at the wreckage.

But I knew that remaining discouraged would lead nowhere.

I began to think about why it had happened.

The clay did not have enough adhesive strength to remain firmly fixed inside the lattice. I also realized that power tools such as a disc grinder or an electric planer produced too much force and vibration. Once a weak section began to break, the damage quickly spread through the surrounding structure.

Through this failure, I learned an important principle firsthand.

"If I want to create the curves of a surfboard from this core, I must work by hand instead of relying on power tools."

The failure had shown me one possible direction.

At the same time, however, it had created a new question.

If I was going to shape it by hand, what kind of tool should I use?