The first thing that you will need to build is the actual HHO generator. This process isn't too bad but it does take a while to run down all of the parts you need. One of the most popular methods is using either stainless steel wires or plates inside of a mason jar. I decided to go with the plates.

For the lid of your generator you will want to find a plastic lid to make sure that you don't short it out. I ended up buying some lids online because I couldn't find what I wanted at the store. This part is pretty easy and just consists of drilling a few holes and attaching some parts to the lid. I put a bubbler cap, a check valve, and a fitting to hook up the vacuum line to on the lid. I still had two holes open for attaching the plates as well.

For the plates I found some stainless steel wall plates in the electrical section at the hardware store. With these I just welded some tabs to the top of them, bent over the tab at the top and drilled a 1/4" hole to attach it to the lid. If you don't have a welder then just use the stainless wire instead of plates, no welding needed for that. I also used nylon bolts and washers to separate the plates from each other and keep them from shorting.

From there all I had to do was bolt the plates to the lid and attach the vacuum hose and the generator was built. I was still a little skeptical if this would work though so I had to try it out.

I pulled the 12V battery out of my lawn mower and hooked it up to the HHO kit to see what would happen. I ran the vacuum line off of the generator into another jar that was filled with water and let it start bubbling. I used a fireplace lighter to light the bubbles as they were coming out of the water. Almost couldn't believe it but this thing actually works and it does make a flammable gas.