After my last post about trying to make a hydrogen generator, things weren’t going too well. So I figured I’d try something different and went out to buy a stainless steel thermos to salvage some decent metal for the project.

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I brought a neodymium magnet with me to check if the “stainless steel” was actually stainless or just some cheap magnetic alloy. I found a generic one that felt right for the job — cost me 20,000 pesos (around 20 USD).

As soon as I got home, I cut into it and peeled off a sheet from the outer wall. But the steel turned out to be really springy and hard to work with. I needed it to be softer so I could flatten it out and shape it into the plates I needed for the HHO generator.

So I decided to anneal it. I fired up a charcoal forge I built, heated the piece until it was glowing red-hot, and then let it cool down slowly. That heat treatment relaxes the internal stresses and softens the stainless steel, making it way easier to work with.

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You can see the color changes after annealing — those rainbow hues are from oxidation, and they’re a good sign that the steel hit the right temperature. Once it was annealed, I managed to flatten the sheet and cut it into square plates for the build.

Not the most elegant process, but it’s definitely working out better than before.

I looked into the specs and found out:

* Most stainless steels (like 304 or 316) need to hit 1,040°C to 1,150°C (1,900°F to 2,100°F) to properly anneal.

* A good charcoal forge (like the one I’m using) can reach up to 1,100°C to 1,200°C (2,000°F to 2,200°F).

So in theory, the setup I’m using should be perfect to get the metal where it needs to be.



##  Here's me making a couple of prototype shapes
While the stainless steel was cooking, I decided to mess around with some aluminum cans to test out what shapes might work best in the jar I’m planning to use—and how I could attach them. I cut a bunch of squares and started figuring out how to stack or space them. This helped me plan the layout I’ll probably go with for the stainless steel version.
![pic 3.jpg](https://images.hive.blog/DQmNoRaDeKHZnjaXhxfuaVmaheA7defrh7LVaroaTAaHFTG/pic%203.jpg)
Once I had a rough idea of the shape and how I’d stack the plates, I felt a lot more confident moving forward. The aluminum can mock-ups were super helpful for planning things out before cutting into the real material.

That’s it for now — just a bit of prototyping and fire, but we’re getting there.

Next post will be all about building the actual HHO generator with the stainless steel plates. Stay tuned!