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Godoh
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Joined: 26/09/2020
Location: Australia
Posts: 528

Posted: 07:46am 27 Jun 2025

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Hi Bryan, well it looks like you have the system working.
Do you have any idea how much gas pressure you will need to have in the bottles to actually do welding/cutting.
I know that the bottles have quite a bit of pressure in them when using acetylene and oxygen for welding, brazing etc, but just how much is not enough is a mystery. Especially using Hydrogen gas.
Do you have to use Oxygen as well as the Hydrogen gas for it to work?
It is great to see how things are going,
pete

Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1433

Posted: 08:03am 27 Jun 2025

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Well Pete it all depends on how much pressure that fridge pump can do so it will be interesting to see how it goes and I may have to machine up a 5 stage pump to get the pressure up.

For a bit of fun I put the acetylene reg on and made sure it was totally closed then when I opened the bottle I could hear a pressure release but nothing on the gauge registered. The E sized bottle is pretty big for what I'm doing and it will take quite a few tubes to get enough to try the oxy torch it is worth persisting.

I am going upto the bridge in the morning to see the BOC bloke as I do need a bottle connection to decanter the Oxy.

Now the hydrogen tube was totally sucked out and laying flat and the power supply is set to 10 volts over night so should see some movement in the morning.

So yes with using hydrogen Oxygen does need to be used to trim the flame and I do have a full E sized bottle here where I'm using LPG with it for silver soldering.

Regards Bryan

Edit: Day 3

Went for a drive to Murray Bridge only to find they only work a 5 day week

and everything was shut. On the way home remembered I did have some old regulators so went for a look in my shearing shed when I got home and the one I wanted was just sitting there

After cleaning out all the wasps nest found a 12mm hose fitted straight over the threaded section. This time I put hose clamps on to stop the hoses blowing off and found the oxy bottle still had about 20psi of oxy left.

Decanted the big tube and the fridge pump chugged along all the way to 40psi and I do think it won't pump much more pressure.

I do have a heap of 12 volt seajet pumps that are 100psi rated for water and they are a dual diaphragm pump so I'll see how they go.

Now one important thing I will need are flash back arresters on the hand piece to avoid blow back with the hydrogen.

So I'll just keep collecting gas over the weekend and on Monday I'll get the gas arresters then it may be time to see if I can get a hydrogen/oxy flame going.
Edited 2025-06-28 12:21 by Bryan1

Revlac

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Joined: 31/12/2016
Location: Australia
Posts: 1151

Posted: 02:16am 28 Jun 2025

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Sounds like your setup is working well

, Good to know the gas not mixed, as we like to do that only at the cutting torch.

I remember a long time ago we talked, and I might have told you about the woodgas I was making, and capturing it with 5 200l plastic drums that were in an old water tank, they would rise up the centre post while filling up, and the compressor would pull that down again.
anyway that worked well and is a story for another time and place, I put the gas into regular gas cylinders to about 130psi later I decided to go a bit more but anyway, if you can get enough pressure and volume into cylinders that the gauge and regulator can be useful and have reasonable working time than is all you need, don't have to have crazy high pressure just find a few more cylinders to fill.

Cheers Aaron
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Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1433

Posted: 05:18am 28 Jun 2025

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I have been thinking when I setup this 330 watt solar panel on a sunny day one expect around 10 amps of current which will overheat this unit in no time

So what I'm thinking is making a second unit to run in parallel so the max current is dropped to 5 amps for each unit.

Now that is best world assumptions and one can expect most of time 60-70% which is still in the ballpark for 2 units.

Now that will cut the run time down by half on filling the tubes so it would become basically a daily task of decanting.

I am going to have a go at using one of those dual diaphragm seajet pumps for the next decant just to see if it works like I think it will. That should let me get the tank to 100psi which should be enough to test.

Just thinking I do have and industrial high pressure water pump here 3,500 psi output so may have set that up on one of my engines and test it out with the hydrogen and oxy gas.

I got this pump at the Callington Auction many years ago and found out it's a brand new pump

I do have a 1/2hp single phase motor here to power it.

What I'm thinking is use the fridge pump as the feed in then the tube can be vacuumed out each time. Then go from the pump to the tank using 1/2" copper tube to deal with the pressure.
Edited 2025-06-28 16:33 by Bryan1

phil99

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Joined: 11/02/2018
Location: Australia
Posts: 2579

Posted: 07:29am 28 Jun 2025

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In most water pumps the water provides lubrication and cooling of internal parts.
If run dry they are quickly ruined.

Bryan1

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Joined: 22/02/2006
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Posts: 1433

Posted: 07:46am 28 Jun 2025

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phil99 said In most water pumps the water provides lubrication and cooling of internal parts.
If run dry they are quickly ruined.

That is true Phill but time it takes to empty the tube is around a minute using the fridge pump. Now when I empty the hydrogen tube tomorrow I will time it and I do think running that short time the pump will be OK.

Anyway I can get spares for this pump as the replacement cost is 3.5K but for me it cost nothing

phil99

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Joined: 11/02/2018
Location: Australia
Posts: 2579

Posted: 12:26pm 28 Jun 2025

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Perhaps a squirt of Lanox or WD40 in the pump inlet before hooking it up will keep it lubricated long enough.
In my experience the lanolin in Lanox sticks to surfaces better than the lubricant in WD40.

Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1433

Posted: 02:49am 29 Jun 2025

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Thats a great idea Phill

I'll put a T=piece at the input of the pump so I can give it a spray before running then just screw the plug back on.

The hydrogen tube is close to full again and the water level on the negative is about 10mm below the water line so I am keeping an eye on it and later this arvo I'll decant it.

Tomorrow I'll go in and get the pulleys and if time allows fabricate up the base so the pump will ready for the third decant as I don't the frodge pump will go much over 40psi pressure.

What has me surprised is the lack of water usage running on 3 amps, I did put a mark on 2 days ago when I topped up the water level after that shutdown due to heat and it's only dropped about 5mm since.

Doing some research yesterday on this pump it is a US made one and the replacement cost of 3.5K US means yes I will treat it with baby gloves

I knew I did have some lanolin spray and did find 2 cans of it one one them is pretty full too

One is the inox brand and the other lanotech so got enough to get me bye.
Edited 2025-06-29 12:52 by Bryan1

Revlac

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Joined: 31/12/2016
Location: Australia
Posts: 1151

Posted: 10:35pm 29 Jun 2025

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Most wobble plate pressure cleaner pumps (not yours) hate pumping air, simply not designed for it, if any of them have a chance it would be the one you have
If you want much higher pressure a multiple stage compressor is the way to go, or just use a car AC unit, I used one of them to pump all my gas and have had it up to 180psi it could go further.

Cheers Aaron
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Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1433

Posted: 11:43pm 29 Jun 2025

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Aaron this pump is a 3 piston pump not a wobble plate so hopefully it will work for me

When I decanted the hydrogen yesterday found leak so fixed it and only got to 30 psi on the second run and a trip up the bridge this week to see the BOC shop hopefully I can get some correct fittings for the tanks to suit the higher pressure.

Revlac

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Joined: 31/12/2016
Location: Australia
Posts: 1151

Posted: 11:58pm 29 Jun 2025

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Bryan, I know its not a wobble plate, thats why I said (not yours) I had one of the exact same type of pump as you have and built the motor and frame for a friend, still have the PTO adaptor drive for it.

Reminds me I need a new seal for the valve on G size oxygen cylinder.

Cheers Aaron
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Bryan1

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Joined: 22/02/2006
Location: Australia
Posts: 1433

Posted: 08:02am 30 Jun 2025

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Well went up to close the shed for the night as I had been out getting my back fixed and the hydrogen tube was full

As the hydrogen was the last fill just had to connect the hose to the tube and when I opened the valve on the bottle no leaks this time

Started the fridge compressor and it easily got the tank to 52psi so pretty happy with that.

Went up to the bridge this morning and got the flash back arrestors and asked about the threaded connectors to the bottles , well after a while I talked them into it so now got one for each bottle with a 1/4" bsp threaded end.

The next decant will be the oxy so I'll make up the proper connection and just see if the fridge compressor will do the next run to 70 psi

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