There have been a few comments by hopeful do it yourselfers who want to store up HHO gas in an old propane tank, etc. This is normally not done for a variety of reasons, and some of the biggest concerns are safety. Here is one comment we received:

The only way that I thought of possibly pressurizing the HHO would be to have the entire system pressurized. So that when the HHO bubbles are made it automatically pressurizes the tank. Then when its at the pressure you desire turn the valve to off and bleed the cell to unpressurize it to add more water or do maintenance. The highest pressure you could probably achieve is about 35-40 PSI without spending a ridiculous amount of money on expensive equipment. The tanks they are using for Hydrogen prototype cars have a cap at about 10,000 PSI But those tanks alone are about $5,000. The main problem here is pressurizing the HHO cell and lines without leaks or explosion.
From what ive seen online people seem to be yielding about 2liters per minute off their HHO cell and receive about 25% increase in efficiency. Wouldn’t you then be able to run your vehicle completly off of 5 HHO cells running simultaneously?

Ok, so here’s a few things to consider. Hydrogen weakens normal metals and materials. This leads to cracks and leaks. A lot of research was done by accredited labs, etc on hydrogen storage years ago. My understanding of the matter is that high pressure hydrogen will find a leak if even the smallest pinhole is present, and escape to atmosphere. Or, escape to the trunk and interior of your car! Also, the average home built unit will have trouble holding much pressure and the gas will start causing small leaks in your system.

Also, HHO is an explosive mixture of hydrogen and oxygen which no sane person would try to store in a jury rigged homemade container in their vehicle. It’s flat out dangerous. Most gases that are stored need oxygen to mix with them to make them burn, ie. propane. The mixing is already done with HHO generators, and this is why sometimes you can have a flashback to your production unit. If you have a little flashback and ruin your generator, that is one thing. How about packing a bomb around in your trunk? Those storage tanks mentioned are for pure hydrogen, which none of us are making with our simple generators.

The best bet in my opinion is to produce the HHO gas and burn it right away as needed in your engine. Never have your hydrogen generator running with the ignition off. Use a flashback arrestor on any high production unit. And always experiment in a well ventilated area when testing your new unit. You don’t want to take any chances.

If you must store hydrogen, you need to have ALL STAINLESS STEEL fittings. You need to use a stainless steel tank. Better yet, an expensive but safe metal hydride tank which will store the hydrogen gas in a solid form. Remember, a regular pressure pump might not have high quality stainless steel insides or corrosion resistant parts unless it is specifically built to handle acid or hydrogen. This goes for most valves, regulators or other parts you might think would work in a pressurized system.

More questions than we can handle! W don’t know all the answers either, but we will try to pass on some of what we have learned from our trial and error. I am going to post some of my thoughts on your comments so everyone will find them.

From: Gary Bruner

Hey guys I ended up making my anode out of stainless steel woven mesh and it works great and I made a simple housing using your design…….now how in the hell do I hook it up to my car. Again thanks in advance and with any luck I’ll be able to tell you about my road test soon!

From: Wooly

Hi Tim. I was wondering if their was a way to have the unit so that it only produced hho when the motor is running. eg: alternater. Or will it just take it from the battery anyway?

I want the unit only running when the motor has started is if people sit with the ignition on for some time. With a litre of hho a minute, it would soon be coming out the exhaust pipe in no time.

Disclaimer: You are responsible for anything you do with HHO information. Be careful! Make sure you take precautions, and don’t assume we have mentioned everything! Hook an untested unit up to a vehicle at your own risk! As far as hooking up your unit, there are a few things to remember. As someone pointed out in the comments, there is a heated wire in the air intake sensors to watch out for. This wire could cause an explosion, or flashback. That leaves the space between that sensor and the throttle body as safe. Don’t hook up on the upstream side of that sensor! If you don’t know vehicles, you need to find someone local who can help you out on where to put the HHO gas into the engine.

Always use a fuse on your wiring. This will help you avoid cooking any wiring in the case of a short circuit. Test your unit off the vehicle to make sure everything is good to go. Depending on how much gas your unit is producing and where you send it into the motor, you probably need a flashback arrestor to protect your generator.

For wiring into your vehicle, we can’t advise you on that since there are so many different variables on all the different models. If one of your buddies knows cars, quiz him up. Otherwise, talk to someone who installs car alarms, stereos, command start or handsfree phone kits for a living. They know more about what wire to tap into than any backyard mechanic.

You definitely have something there, Wooly. It is really important to make sure your unit isn’t running when the vehicle is shut off. That is why, for wiring, you should get professional advice or help. If it is your own vehicle, I guess you can take your chances with jury rigging a simple switch temporarily if you want. Don’t modify a vehicle for someone else and make it dangerous to use.

Another question we’ve been hearing, is where to find stainless steel for your HHO Fuel Cell. There are a lot of places to look, all around us. Aside from the obvious choice of a metal manufacturer, machine shop or a welding supply store, even Costco has stainless cookwear.

Our first HHO hydrogen generator was made out of a stainless steel stock pot. We bought it brand new for $9.99 at a nearby department store. You can’t cut stainless with an acetylene torch, so other methods had to be found. An angle grinder with a zip disk was used to cut two strips out of the pot. They were pretty thin and hard to work with, but the anode did produce hydrogen right off the first try. Note: there were a lot of razor sharp edges and a couple of cuts, so be careful if you try this! Wear safety glasses and gloves if you use any grinding or cutting equipment.

Since then we have been buying plate in 4 foot by 8 foot sheets. Since this isn’t practical for everyone, you can use a variety of kitchen and household items. From platters, to pots, to pitchers, many items are made from 304 stainless.

Speaking of which, some would have you believe that you need to use 316 stainless. We can’t figure out why you would need that, unless you will be running acid or hydrogen sulfide through your HHO fuel cell. 316 has extra hardener and anti corrosive elements to it, which also make it harder to bend and cut. So far, none of the 304 we have used has degraded measurably. 304 will conduct a current just as well as 316, and both are non magnetic.

If yo can’t find stainless steel plate to build your hydrogen generator, we can help you out. We can supply 16 gauge  4″ x 4″ & 4″ x 12″ 304 stainless steel plates, precut and ready to use. The details can be found in the Storefront widget on the right side. Before you buy, look around and see if you can locate what you need locally to save yourself shipping.

We have gotten a lot of questions about bubbler containers, overheating of HHO generators and things related.Here is a recent comment:

• Hey guys, I build a simple HHO generator and I got a good output I tested it already with my nissan sentra 1.6L ‘93model, my exhaus emit drops of water. My only problem is the water inside my HHO generator getting too hot, do I need to add cooling device or have something to adjust in my generator? I used spiral stainless wire with 13 turns .5 inch gap., distilled water with 1 teaspoon of baking soda. thanks,
  Allan / Manila, Philippines

First off, good work so far, Allen. There are quite a few things to cover here. The water can get pretty hot if your container can handle it. If it is made out of PVC, you have to be careful that it stays below 70 degrees Celsius or the plastic will start to ‘creep’ and change shape as the material becomes slightly liquid. A stainless steel or internally coated metal container could of course handle any temperature you might subject it to. A glass container can take heat but not impacts or any possible explosions. If you have to use PVC or other plastic, you will need to cool your fuel cell. Similarly, if your hydrogen generator is boiling the water it will need cooling to keep the water from steaming out of the unit.

A bubbler tank can help circulate the water and reduce the chances of a flashback destroying your generator at the same time. In the following video we show one experiment we filmed using a small bubbler tank to recirculate the water. The unit we were testing was composed of 4 stainless steel strips, 1 inch wide by 12 inches long, sandwiched together with a 1/8 inch gap. The HHO fuel cell was drawing over 20 amps. The more amps, the more heat produced. This small bubbler tank failed to keep the unit cool enough. Our conclusions were that this unit would need a bubbler at least as large as the unit itself, or a small cooler such as for a transmission. We decided to go with a smaller unit to reduce electrical use and keep the heat production down.

One of the most common containers being made for a simple HHO generator is a tube made from PVC pipe. PVC is found at hardware stores all over North America. It is relatively inexpensive and easy to work with. More complicate containers would be made from stainless steel or regular steel that has been internally coated after construction. For the home enthusiast or tinkerer, these types of containers may be more than they want to take on. Just to get involved in hydrogen generators, you can build a cheap PVC housing with just a few tools.
What You Need for one housing and a bubbler - recirculate tank:

1. PVC pipe - 3″ ,or 4″
2. End caps of same size as pipe
3. 1/2″ threaded fittings with 3/8″ tubing outlet
4. 1/2″ thread tap
5. Drill and bits
6. Wood hand saw or other tool to cut pipe
7. Plastic glue, marine epoxy or other waterproof sealant
8. PVC glue
9. 3/8″ Plastic tubing or rubber fuel line tubing

The first step is to drill holes for your inlet and outlet, then use the thread tap to thread them for your fittings. If you have never done this, you need to make a hole smaller than the tap or you will be getting a new end cap! On our coiled anodes,we use a torch to heat the ends of our electrical connection tabs until they are hot enough to melt holes in the plastic, then push them through the cap. If you are using bolts or wires or some other electrical connection, you will have to drill holes for those too. We don’t recommend ANY internal connections unless you really know what you are doing. Watch our Hydrogen Generator Safety video for more info.

Once you have used the PVC glue to attach the bottom end cap, it is time to fit your anodes and top end cap together, which will depend on what style of generator anodes you have decided to use. You will need to seal with glue any spots that don’t have a tight fit.

The threaded fittings need teflon tape or thread sealant to keep them from leaking. It is best not to glue these since you might want to remove them later.

Many people put a sight glass on the side to check water level, and this is done by tapping and threading a couple more holes on the side of your housing. Threaded fittings top and bottom point towards each other, with a piece of clear tubing between.

Making a bubbler tank is very similar. This one should have a fitting on it for gas/ water in from the generator, a return line, and a gas out line. The in and return lines need to be located near  the bottom of the bubbler, below the fluid level. The gas out line should be at the highest point of the unit.

Next post we will have pictures of a complete setup.

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Aron and I have made several styles of HHO hydrogen generators. The easiest one to build was the wrapped cylindrical model. It is composed of 2 stainless steel 16 gauge plates, rolled into a cylinder. We cut a strip part way on each one, then bend it up to use for a connector lead. This means we can build a cell with no internal connections, since our electrical lead extends out of the casing. In this video clip, we show our home made roller, our finished anodes and a quick test in pre-treated tap water to make sure everything is working. The water was used before with a different generator, but has no electrolytes or caustic additives. Adding electrolyte to the solution would increase production of this cell drastically, but we always test without it first. To see a test of a cell very similar to this, look at HHO Hydrogen Fuel Cell #4 Demo.

For anyone who wants one of these generator anodes, but doesn’t want to build one themselves, check out our sales box on the right. These anodes will fit inside a 3″ PVC housing, but would require a bubbler tank with recirculating capabilities to avoid overheating. We have yet to find a design which makes large quantities of HHO without heating up.

A few weeks ago we were testing one of out HHO generators. The video here is from that test. If you want to see how we made an HHO cell a lot like this, see How to Make an HHO Fuel Cell Anode.
Here’s what we show in this clip:
1. the test fuel cell hanging in pure water, with 2 amps DC running through it and producing hydrogen and oxygen (two hydrogen for one oxygen, which is the explosive HHO mixture)
2. the HHO fuel cell in its case and bubbling the hydrogen gas through water, which we timed and caught in a jar to measure production.
3. the HHO hydrogen generator bubbling into soapy water, so we can catch the bubbles to light them with a BBQ lighter. This is really loud, like earsplitting. It’s hard to believe how much force there is in just a little of this gas.
4. the hydrogen fuel cell hooked up and running the HHO to a Ford half ton. We used an older vehicle, just in case something went wrong. Expendable trucks first, please!

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Aron and I have started to build our own homemade HHO fuel cells. What we are working on isn’t rocket surgery, folks. These basic fuel cells that everyone on the internet seems to be churning out aren’t very complicated. Even so, you can really screw up and cause an explosion. In fact, we did blow up our second HHO prototype. It was on Aron’s table in his house when both end caps and the anodes blew out of the casing. Our best guess is that a corroded connection arced and lit the hydrogen oxygen gas mixture, resulting in a blast that Aron says nearly blew his eardrums and the windows in his kitchen. No one was hurt, but the generator is non functional. We have since improved our design by removing all wires and soldered connections with a one piece anode made from stainless steel (corrosion proof).
If you go to look at our video on YouTube, you will see that Smartscarecrow left a comment pointing out we would have had a real problem if we had used a glass container instead of plastic. You may know that there are units with glass containers being sold online. I wonder how one of these units would hold up mounted under the hood of a car, with vibration and possible road garbage bouncing up.

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When Aron and I first started talking about hydrogen and uses for it, it was 1996. It was a little beyond both of us at the time. We didn’t have the resources we do now.

Lately, it seems like hydrogen information is coming out of the woodwork. We started trying to make our own hydrogen generators in the last while, since it isn’t really that complex. And we aren’t alone; many others are busy building their own HHO.

A lot of people want to find out more about homemade hydrogen generators. Not everyone will actually build one. Many of you probably just find it an interesting idea, and others will decide actually building one will be more work than they want to do themselves.

We can help out there, too. We will be reviewing the products of others, as well as showing you how we made our HHOs. We will give you links to materials ans even to completed units. Check back here later, or subscribe for email HHO hydrogen article updates.